WO2022022675A1

WO2022022675A1 - Image source, head-up display, and traffic device

Info

Publication number: WO2022022675A1
Application number: PCT/CN2021/109526
Authority: WO
Inventors: 徐俊峰; 吴慧军; 方涛
Original assignee: 未来（北京）黑科技有限公司
Priority date: 2020-07-30
Filing date: 2021-07-30
Publication date: 2022-02-03
Also published as: CN114063284A

Abstract

An image source (10), a head-up display, and a traffic device. In the image source (10), the light rays emitted by the light source (100) have a first polarisation and a second polarisation different to the first polarisation, and an image generating part (200) is configured to use first polarised light (101) having the first polarisation or second polarised light (102) having the second polarisation to generate image light rays; a beam splitting element (300) is configured to split the light rays incident on the beam splitting element (300) into first polarised light (101) and second polarised light (102), the first polarised light (101) being propagated to the image generating part (200), and the second polarised light (102) being propagated to a direction changing element (400); the direction changing element (400) is configured to change the propagation direction of the light rays incident on the direction changing element (400) to direct same towards the image generating part (200); a polarisation conversion element (500) is configured to convert the polarised light amongst the first polarised light (101) and the second polarised light (102) that cannot be used by the image generating part (200) into polarised light that can be used by the image generating part (200) before the polarised light reaches the image generating part (200), thereby increasing the rate of utilisation of the light rays emitted by the light source.

Description

Image sources, head-up displays, and transportation equipment

This application claims the priority of Chinese Patent Application No. 202010754547.6 filed on July 30, 2020, and the contents disclosed in the above Chinese patent application are hereby cited in their entirety as a part of this application.

technical field

At least one embodiment of the present disclosure relates to an image source, a heads-up display, and a transportation device.

Background technique

Head Up Display (HUD) technology can use reflective optical design to project image light (including vehicle information such as vehicle speed) from an image source onto an imaging window (such as windshield, imaging panel, etc.) The driver can directly see the information without looking down at the instrument panel during driving, which can not only improve the driving safety factor, but also bring a better driving experience.

SUMMARY OF THE INVENTION

At least one embodiment of the present disclosure provides an image source, a heads-up display, and a transportation device.

At least one embodiment of the present disclosure provides an image source, including: a light source and an image generating part. The light emitted by the light source has a first polarization and a second polarization different from the first polarization, and the image generating unit is configured to use the first polarization having the first polarization or the first polarization having the first polarization. The bipolar second polarized light generates image light. The image source further includes a beam splitting element, a direction changing element and a polarization conversion element, the beam splitting element is configured to split the light emitted by the light source and incident on the beam splitting element into the first polarized light and the second polarized light, the first polarized light propagating to the image generating section, the second polarized light propagating to the direction changing element; the direction changing element configured to change the incident to the The second polarized light propagation direction of the direction changing element is directed toward the image generating portion; the polarization conversion element is configured to convert the first polarized light and the second polarized light that cannot be The polarized light utilized by the image generating unit is converted into polarized light usable by the image generating unit before the polarized light reaches the image generating unit.

For example, the first polarized light or the second polarized light used by the image generating unit includes polarized light obtained by converting one of the first polarized light and the second polarized light by the polarization conversion element, and The other of the first polarized light and the second polarized light not converted by the polarization conversion element.

For example, in any of the above embodiments of the present disclosure, both the first polarized light and the second polarized light include linearly polarized light, and the image generating part includes a polarizing layer, and the polarizing layer is located in the image generating section. The side of the portion close to the light source, and the polarization axis of the polarizing layer is parallel to the polarization direction of the first polarized light or the second polarized light, and the polarization conversion element is configured to convert the first polarized light Among the light and the second polarized light, the polarized light whose polarization direction is not parallel to the polarization axis is converted into polarized light whose polarization direction is parallel to the polarization axis before the polarized light reaches the image generating section.

For example, in any of the above embodiments of the present disclosure, the polarization axis of the polarizing layer is parallel to the polarization direction of the second polarized light, and the beam splitting element is configured to detect the light having the first polarization The transmittance is greater than the transmittance of the light with the second polarization, and/or the reflectivity of the light with the second polarization is greater than the reflectance of the light with the first polarization, so the direction changing element is configured to reflect the second polarized light incident on the direction changing element to the image generating portion; the polarization converting element is located between the beam splitting element and the image generating portion, and is configured to convert the first polarized light transmitted from the beam splitting element into the second polarized light, and the second polarized light obtained by the conversion is directed toward the image generating unit.

For example, in any of the above embodiments of the present disclosure, the polarization axis of the polarizing layer is parallel to the polarization direction of the first polarized light, and the beam splitting element is configured to detect the light having the first polarization The transmittance is greater than the transmittance of the light with the second polarization, and/or the reflectivity of the light with the second polarization is greater than the reflectance of the light with the first polarization, so The beam splitting element is configured to transmit the light having the first polarization among the light source rays to the image generating unit, and reflect the light having the second polarization among the light source rays to the image generating unit. the direction changing element. The polarization conversion element is located between the direction change element and the image generation part and is configured to convert the second polarized light reflected from the direction change element to the first polarized light, and the resultant obtained by conversion is the first polarized light is directed towards the image generating section; or the polarization conversion element is located between the direction changing element and the beam splitting element and is configured to be reflected from the beam splitting element towards the The second polarized light of the direction changing element is converted into the first polarized light, and the direction changing element is configured to reflect the first polarized light obtained by the conversion to the image generating section.

For example, in any of the above embodiments of the present disclosure, where the polarization conversion element is located between the direction changing element and the beam splitting element, the polarization conversion element is configured to convert the second The polarized light is converted to the first polarized light, or the polarization conversion element is configured to convert the second polarized light reflected from the beam splitting element toward the direction changing element to a third polarized light, so The third polarized light is reflected by the direction changing element and then passes through the polarization conversion element again and is converted into the first polarized light, and the first polarized light obtained through the conversion is directed to the image generating unit.

For example, in any of the above embodiments of the present disclosure, the direction changing element is located outside or in the optical path in which the polarization converting element is located. Among the first polarized light and the second polarized light, the polarized light that is not converted by the polarization conversion element is processed by the direction changing element and then used by the image generating unit; or, the first polarized light After one of the polarized light and the second polarized light is processed by the direction changing element, it is converted into the polarized light that can be used by the image generating unit through the polarization conversion element; or the first polarized light and the second polarized light After one of the polarization conversion elements is converted into polarized light that can be used by the image generation part, it is processed by the direction changing element; or one of the first polarized light and the second polarized light is processed by The polarization conversion element is converted for the first time, then processed by the direction changing element, and then converted into polarized light that can be used by the image generating unit after being converted for the second time by the polarization conversion element.

For example, in any of the above embodiments of the present disclosure, the polarization conversion element is configured to convert polarized light incident thereon at least once. The polarization conversion element is configured to convert the polarized light incident thereon once, and the polarization conversion element includes a half-wave plate; the polarization conversion element is configured to convert the polarized light incident thereon Two conversions are performed, and the polarization converting element includes a quarter wave plate.

For example, in any of the above embodiments of the present disclosure, the polarization conversion element is attached to at least one of the beam splitting element and the direction changing element.

For example, in any of the above embodiments of the present disclosure, a transparent substrate is provided between the polarization conversion element and at least one element attached thereto, and the polarization conversion element and the element attached thereto are respectively attached to the Two surfaces of the transparent substrate that are opposite to each other are arranged in parallel.

For example, in any of the above embodiments of the present disclosure, the polarization directions of the first polarized light and the second polarized light are perpendicular, and one of the first polarized light and the second polarized light includes S polarization The other one of the first polarized light and the second polarized light includes the light of the P polarized state.

For example, in any of the above embodiments of the present disclosure, the direction changing element is located on the side of the beam splitting element facing the light source, and the beam splitting surface of the beam splitting element and the reflective surface of the direction changing element Or, the beam splitting surface of the beam splitting element and the reflection surface of the direction changing element have a non-zero included angle.

For example, in any of the above embodiments of the present disclosure, the image source includes a plurality of light conversion parts, and each light conversion part includes one of the beam splitting elements, one of the direction changing elements, and one of the polarization conversion elements, The number of the light sources is multiple, the multiple light sources and the multiple light conversion parts are arranged in a one-to-one correspondence, and the light emitted by each light source passes through a corresponding light conversion part and then goes to the image generation part.

For example, in any of the above embodiments of the present disclosure, the image generating section includes a liquid crystal display panel.

For example, in any of the above embodiments of the present disclosure, the image source further includes a reflective light guide element, a light beam condensing element, and a light beam diffusing element, and at least part of the reflective light guide element is located between the light source and the beam splitter. between the elements, and is configured to reflect the light emitted by the light source so that the light emitted from the reflective light guide element is collimated light; The light beams are converged; the beam diffusing element is located between the beam condensing element and the image generating part, and/or between the beam splitting element and the reflective light guide element, and is configured to pass through The light beam of the light beam diffusing element is diffused.

For example, in any of the above embodiments of the present disclosure, the image generating part is located on the light exit side of the light source; the beam splitting element is located between the light source and the image generating part.

For example, in any of the above embodiments of the present disclosure, the polarization conversion element is attached to a side of the beam splitting element away from the direction changing element.

For example, in any of the above embodiments of the present disclosure, a transparent substrate is provided between the beam splitting element and the polarization conversion element, and the beam splitting element and the polarization conversion element are respectively attached to the transparent substrate The two surfaces facing each other are arranged in parallel.

For example, in any of the above embodiments of the present disclosure, in the case where the polarization conversion element converts the polarized light incident thereon twice, the polarization conversion element is attached to the direction changing element to face One side of the beam splitting element; a transparent substrate may be arranged between the direction changing element and the polarization conversion element, and the direction changing element and the polarization conversion element are respectively attached to opposite sides of the transparent substrate. two surfaces.

For example, in any of the above embodiments of the present disclosure, the reflective element and the polarization conversion element are arranged to be attached to each other.

At least one embodiment of the present disclosure provides a head-up display, comprising: any of the above image sources; and a reflective imaging unit configured to reflect light emitted from the image source to an observation area and transmit ambient light.

For example, in at least one embodiment of the present disclosure, the reflective imaging part is provided with a wedge-shaped film, and the wedge-shaped film is located in the interlayer of the reflective imaging part; or, the reflective imaging part faces the surface of the image source A selective reflection film is provided, and the selective reflection film is configured so that the reflectivity of the wavelength band where the image light emitted from the image generating part is located is greater than the reflectivity of the wavelength band other than the wavelength band where the image light is located; or, the The light emitted by the image generation part toward the reflection imaging part includes light in a P-polarized state, and a surface of the reflection imaging part facing the image source is provided with a P-polarized light reflection film to reflect the image generation part toward the image source. The light of the P-polarized state of the reflection imaging part; or, the light of the image generating part directed to the reflection and imaging part includes the light of the S-polarized state, and the surface of the reflection imaging part facing the image source is provided with a No. a phase retardation part, the first phase retardation part is configured to convert the light of the S polarization state incident into the first phase retardation part into the light of the non-S polarization state.

For example, in any of the above embodiments of the present disclosure, the head-up display further includes: a second phase retardation part located between the image source and the reflection imaging part. The light emitted by the image generating part includes light in an S-polarized state, and the second phase retardation part is configured to convert the light in the S-polarized state incident to the second phase retardation part into a light in a circular polarization state or The light in the elliptically polarized state, the converted light in the circularly polarized state or the elliptically polarized state is reflected by the reflection imaging part and then directed to the observation area.

At least one embodiment of the present disclosure provides an image source including a light source and an image generating part. The image generating part is located on the light-emitting side of the light source, the light emitted by the light source includes a first polarized light and a second polarized light whose polarization directions are perpendicular, and the image generating part is configured to use the first polarized light or the second polarized light. The second polarized light generates image light. The image source further includes a beam splitting element, a direction changing element, and a polarization conversion element, the beam splitting element being located between the light source and the image generating section and configured to divert light incident to the beam splitting element The beam splitting is the first polarized light and the second polarized light, the first polarized light is directed to the image generating part, and the second polarized light is directed to the direction changing element; the direction changing element is configured to change the propagation direction of light incident on the direction changing element so as to be directed toward the image generating portion; the polarization converting element is configured to convert the first polarized light and the second polarized light into The polarized light that cannot be utilized by the image generating unit is converted into polarized light that can be utilized by the image generating unit before reaching the image generating unit.

For example, in at least one embodiment of the present disclosure, the image generating part includes a polarizing layer, the polarizing layer is located on a side of the image generating part close to the light source, and the polarization axis of the polarizing layer is parallel to the light source. the polarization direction of the first polarized light or the second polarized light, and the polarization conversion element is configured to convert the polarization direction of the first polarized light and the second polarized light that is not parallel to the polarization axis The light is converted into polarized light whose polarization direction is parallel to the polarization axis before reaching the image generating section.

For example, in any of the above embodiments of the present disclosure, the polarization axis of the polarizing layer is parallel to the polarization direction of the second polarized light, and the beam splitting element is configured to transmit the first of the light sources polarized light reflecting the second polarized light in the light source to the direction changing element configured to reflect the second polarized light incident on the direction changing element to the image a generating portion; the polarization converting element is located between the beam splitting element and the image generating portion, and is configured to convert the first polarized light transmitted from the beam splitting element to the second polarized light , the converted second polarized light is directed to the image generating part.

For example, in any of the above embodiments of the present disclosure, the polarization axis of the polarizing layer is parallel to the polarization direction of the first polarized light, and the beam splitting element is configured to transmit the first one of the light sources polarized light to the image generating portion, reflecting the second polarized light in the light source to the direction changing element, the polarization conversion element being located between the direction changing element and the image generating portion and being The second polarized light reflected from the direction changing element is configured to be converted into the first polarized light, and the converted first polarized light is directed toward the image generating section.

For example, in any of the above embodiments of the present disclosure, the polarization axis of the polarizing layer is parallel to the polarization direction of the first polarized light, and the beam splitting element is configured to transmit the first one of the light sources polarizing light to the image generating section, and reflecting the second polarized light in the light source toward the direction changing element, the polarization conversion element being located between the direction changing element and the beam splitting element, and is configured to convert the second polarized light reflected from the beam splitting element towards the direction changing element to the first polarized light, the direction changing element being configured to convert the converted first polarized light The polarized light is reflected to the image generating section.

For example, in any of the above embodiments of the present disclosure, the polarization converting element includes a half wave plate.

For example, in any of the above embodiments of the present disclosure, the polarization axis of the polarizing layer is parallel to the polarization direction of the first polarized light, and the beam splitting element is configured to transmit the first one of the light sources polarizing light to the image generating section, and reflecting the second polarized light in the light source toward the direction changing element, the polarization conversion element being located between the direction changing element and the beam splitting element, and is configured to convert the second polarized light reflected from the beam splitting element towards the direction changing element to a third polarized light, the third polarized light being reflected by the direction changing element and passing through the polarization The conversion element is then converted into the first polarized light, and the converted first polarized light is directed to the image generating unit.

For example, in any of the above embodiments of the present disclosure, the third polarized light is circularly polarized light or elliptically polarized light.

For example, in any of the above embodiments of the present disclosure, the polarization converting element comprises a quarter wave plate.

For example, in any of the above embodiments of the present disclosure, one of the first polarized light and the second polarized light includes light in an S-polarized state, and the other of the first polarized light and the second polarized light A ray that includes the P-polarized state.

For example, in any of the above embodiments of the present disclosure, the direction changing element is located on the side of the beam splitting element facing the light source, and the beam splitting surface of the beam splitting element and the reflective surface of the direction changing element parallel.

For example, in any of the above embodiments of the present disclosure, the image source further includes a reflective light guide element, a beam condensing element, and a beam diffusing element. At least part of the reflective light guide element is located between the light source and the beam splitting element, and is configured to reflect light emitted by the light source to collimate the light emitted from the reflective light guide element a light beam; the beam condensing element is located between the direction changing element and the beam splitting element and the image generating portion, and is configured to align the light ray emitted from the direction changing element to the image generating portion and all The light beams emitted by the beam splitting element towards the image generating part are converged; the light beam diffusing element is located between the beam condensing element and the image generating part, and/or is located between the beam splitting element and the reflection guide between the optical elements, and is configured to spread the light beam passing through the light beam diffusing element.

At least one embodiment of the present disclosure provides a head-up display, including: the image source provided in any of the foregoing embodiments and a reflection imaging unit. The reflection imaging part is located on the light emitting side of the image source, and is configured to reflect the light emitted from the image source to the observation area and transmit ambient light.

For example, in at least one embodiment of the present disclosure, the reflective imaging portion is provided with a wedge-shaped film, and the wedge-shaped film is located in the interlayer of the reflective imaging portion.

For example, in any of the above embodiments of the present disclosure, a surface of the reflective imaging part facing the image source is provided with a selective reflective film, and the selective reflective film is configured to reflect the image emitted by the image generating part The reflectivity of the wavelength band where the light is located is greater than the reflectivity of the wavelengths other than the wavelength band where the image light is located.

For example, in any of the above embodiments of the present disclosure, the light emitted by the image generating portion toward the reflective imaging portion includes light in a P-polarized state, and the surface of the reflective imaging portion facing the image source is provided with P-polarized light. The light reflection film reflects the light of the P-polarized state emitted by the image generating part toward the reflection imaging part.

For example, in any of the above embodiments of the present disclosure, the light emitted by the image generating portion toward the reflective imaging portion includes light in an S-polarized state, and the surface of the reflective imaging portion facing the image source is provided with a first A phase retardation part, the first phase retardation part is configured to convert the light of the S polarization state incident into the first phase retardation part into the light of the non-S polarization state.

At least one embodiment of the present disclosure provides a transportation device, including the head-up display provided by any of the foregoing embodiments.

For example, in at least one embodiment of the present disclosure, the reflective imaging portion is a windshield of the traffic equipment.

Description of drawings

In order to explain the technical solutions of the embodiments of the present disclosure more clearly, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, rather than limit the present disclosure. .

FIG. 1A is a schematic partial structure diagram of an image source provided according to at least one example of an embodiment of the present disclosure;

FIG. 1B is a schematic partial structure diagram of an image source provided according to at least one example of an embodiment of the present disclosure;

1C is a schematic diagram of a partial structure of a liquid crystal display panel provided according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of the bonding arrangement of the beam splitting element and the polarization conversion element shown in FIG. 1B ;

3 is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure;

4 is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure;

5 is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure;

6 and 7 are schematic diagrams of partial structures of an image source provided according to at least one example of an embodiment of the present disclosure;

8A to 8C are schematic structural diagrams of different reflective light guide elements provided according to at least an embodiment of the present disclosure;

FIG. 9 is a schematic partial structure diagram of an image source provided according to at least one example of an embodiment of the present disclosure;

FIG. 10 is a schematic structural diagram of a beam condensing element provided according to at least one embodiment of the present disclosure;

11 is a schematic diagram of an optical path of a combination of a beam condensing element and a beam diffusing element provided according to at least one embodiment of the present disclosure;

12A is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure;

12B is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure;

13 is a schematic partial structural diagram of a head-up display provided according to at least one embodiment of the present disclosure;

14 is a schematic partial structural diagram of a head-up display provided according to another example of at least one embodiment of the present disclosure;

15 is a schematic partial structural diagram of a head-up display provided according to another example of at least one embodiment of the present disclosure;

FIG. 16 is a schematic partial structural diagram of a head-up display provided according to another example of at least one embodiment of the present disclosure; and

17 is an exemplary block diagram of a transportation device provided in accordance with at least one embodiment of the present disclosure.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present disclosure.

Unless otherwise defined, technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. As used in this disclosure, "first," "second," and similar terms do not denote any order, quantity, or importance, but are merely used to distinguish the various components. "Comprises" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things.

The features such as "parallel", "perpendicular" and "same" used in the embodiments of the present disclosure all include features such as "parallel", "perpendicular", "same" in strict sense, and "substantially parallel", "substantially perpendicular", Conditions such as "substantially the same" and the like contain some error, given the measurement and the errors associated with the measurement of the specified quantity (ie, limitations of the measurement system), and represent what is acceptable for the specified value as determined by one of ordinary skill in the art within the deviation range. For example, "approximately" can mean within one or more standard deviations, or within 10% or 5% of the stated value. The dimensions and proportions of elements in the drawings are only schematic and do not limit the dimensions and proportions of actual elements. "At least one" mentioned in this disclosure means "one or more", and "a plurality" mentioned in this disclosure means "at least two", that is, "two or more".

During research, the inventors of the present disclosure found that when a head-up display (HUD) projects an image on an imaging window such as a vehicle windshield, the image source of the HUD requires a high display brightness so that the driver can clearly see What the HUD displays. For example, imaging brightness can be increased by increasing the power of the HUD's image source. However, the method of improving the imaging brightness by increasing the power of the image source of the HUD not only causes the problems of high power consumption and heat generation of the image source, but also needs to meet the high heat dissipation requirements of the HUD.

The following describes the image source, head-up display, and traffic equipment provided by the embodiments of the present disclosure with reference to the accompanying drawings and specific embodiments. For multiple protection subjects such as head-up displays and traffic equipment, the same or similar content is not repeated in each protection subject, and reference may be made to the descriptions in the embodiments corresponding to other protection subjects.

At least one embodiment of the present disclosure provides an image source, a heads-up display, and a transportation device. The image source includes a light source and an image generating section. The light emitted by the light source has a first polarization and a second polarization different from the first polarization, and the image generating unit is configured to use the first polarization with the first polarization or the second polarization with the second polarization Generate image rays. The image source further includes a beam splitting element, a direction changing element and a polarization conversion element. The beam splitting element is configured to split the light emitted by the light source and incident on the beam splitting element into a first polarized light and a second polarized light, the first polarized light being the first polarized light. Propagating to the image generating portion, the second polarized light propagates to the direction changing element; the direction changing element is configured to change the propagation direction of the light incident on the direction changing element so as to be directed toward the image generating portion; the polarization converting element is configured to convert the first Among the first polarized light and the second polarized light, the polarized light that cannot be utilized by the image generating unit is converted into polarized light that can be utilized by the image generating unit before the polarized light reaches the image generating unit. In at least one embodiment of the present disclosure, by arranging a beam splitting element, a direction changing element and a polarization converting element in the image source, the utilization efficiency of the light emitted by the light source can be improved, so that the light source can provide images with higher brightness under the same power condition .

The image source, the head-up display, and the transportation equipment provided by the embodiments of the present disclosure are described below with reference to the accompanying drawings.

FIG. 1A is a schematic partial structural diagram of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 1A , the image source 10 includes a light source 100 and an image generation unit 200 . The image generating part 200 is located on the light-emitting side of the light source 100 , for example, the light emitted by the light source 100 may be directed to the image generating part 200 ; For example, the light source 100 may be located on the side or the back of the image generating part 200 . In any example of the embodiments of the present disclosure, "shooting" may include direct shooting or indirect shooting. Direct shooting refers to the ray directly shooting towards the target component without passing through other optical elements, and indirect shooting refers to the light passing through one or more other optical elements. Optical elements, such as reflective elements, polarization conversion elements, beam condensing elements, and beam diffusing elements, etc., are then directed toward the target component. For example, the light emitted by the light source 100 may be directed to the image generating unit 200 without passing through other optical elements, or may be directed to the image generating unit 200 after being reflected by, for example, a mirror. The light emitted by the light source 100 has a first polarization and a second polarization different from the first polarization. For example, the light emitted by the light source 100 includes a first polarized light 101 and a second polarized light 102 whose polarization directions are perpendicular, and the light emitted by the light source 100 is unpolarized light. The "non-polarized light" here means that the light emitted by the light source can have multiple polarization characteristics at the same time but does not exhibit a unique polarization characteristic. The unpolarized light emitted by the light source can be decomposed into two mutually orthogonal/perpendicular polarization states. The image generating section 200 is configured to generate image light using the first polarized light having the first polarization or the second polarized light having the second polarization. For example, the image generation part 200 is configured to generate image light using the first polarized light 101 or the second polarized light 102 , for example, one of the first polarized light 101 and the second polarized light 102 can be used by the image generation part 200 to generate an image Polarized light of light. For example, the polarized light usable by the image generating unit may refer to polarized light that can be incident inside the image generating unit, or may refer to polarized light required when the image generating unit forms image light of a specific polarization state.

As shown in FIG. 1A , the image source 10 further includes a beam splitting element 300 , a direction changing element 400 and a polarization converting element 500 . The beam splitting element 300 is configured to split the light emitted by the light source 100 and incident on the beam splitting element 300 into a first polarized light 101 and a second polarized light 102. Polarized light 102 propagates to direction changing element 400 . For example, after the light emitted by the light source 100 is incident on the beam splitting element 300, it can be split into two polarized lights whose polarization directions are perpendicular to each other. The first polarized light 101 described above is directed toward the image generating unit 200 , and the second polarized light 102 is directed toward the direction changing element 400 . For example, FIG. 1A schematically shows that the first polarized light 101 is directly directed toward the image generating unit 200 , and the second polarized light 102 is directed toward the direction changing element 400 , but not limited to this, the first polarized light 101 may also pass through other optical systems Elements, such as optical elements such as the beam condensing element 700 and the beam diffusing element 800 described later, are directed to the image generating part 200 ; for example, the second polarized light 102 can also be directed to the direction changing element 400 after passing through other optical elements. For example, the propagation direction of the light emitted by the light source 100 before being split by the beam splitting element 300 is the same as the propagation direction of the first polarized light 101 , both of which are propagated to the image generating unit 200 ; The propagation direction before beam splitting is different from the propagation direction of the second polarized light 102 before being incident on the direction changing element 400 . For example, the beam splitting element 300 is located between the light source 100 and the image generating part 200 ;

As shown in FIG. 1A , the direction changing element 400 is configured to change the propagation direction of the light incident on the direction changing element 400 , eg, the second polarized light 102 , so as to be directed toward the image generating section 200 . For example, the light incident on the direction changing element 400 may also be the light after polarization conversion of the second polarized light 102 , such as the light 103 described later. For example, at least part of the second polarized light 102 split by the beam splitting element 300 propagates toward the direction changing element 400 , and the direction changing element 400 can change the propagation direction of the second polarized light 102 directed to the direction changing element 400 . For example, the above-mentioned second polarized light 102 directed toward the image generating unit 200 may include the second polarized light 102 directly directed toward the image generating unit 200 without passing through other optical elements, or may include the second polarized light passing through other optical elements, for example, as described later. The optical elements such as the beam condensing element and the beam diffusing element are sent to the image generating section. As shown in FIG. 1A , the polarization conversion element 500 is configured to convert the polarized light that cannot be utilized by the image generation unit 200 among the first polarized light 101 and the second polarized light 102 into an image capable of being generated by the image generation unit 200 before reaching the image generation unit 200 . section 200 utilizes polarized light. For example, the polarized light that cannot be used by the image generating unit may refer to the polarized light that cannot be incident inside the image generating unit. The light may refer to polarized light that is not selected by the image generating section.

The image source provided in at least one embodiment of the present disclosure utilizes a beam splitting element, a direction changing element, and a polarization converting element to convert almost all the unpolarized light emitted by the light source into light with a specific polarization state that can be utilized by the image generating unit, which can improve the The utilization rate of the light emitted by the light source, the light source can provide images with higher brightness under the same power conditions.

FIG. 1B is a schematic partial structural diagram of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 1B , the image source 10 includes a light source 100 and an image generation unit 200 . The image generating unit 200 is located on the light-emitting side of the light source 100 , for example, the light emitted by the light source 100 is directed to the image generating unit 200 . The light emitted by the light source 100 includes a first polarized light 101 and a second polarized light 102 whose polarization directions are vertical. For example, the light emitted by the light source 100 is unpolarized light. The image generating part 200 includes a polarizing layer 210 located on the side of the image generating part 200 close to the light source 100 , and the polarization axis of the polarizing layer 210 is parallel to the polarization direction of the first polarized light 101 or the second polarized light 102 . For example, when the polarization axis of the polarizing layer 210 is parallel to the first polarized light 101, the first polarized light 101 can pass through the polarizing layer 210 and then enter the image generating part 200, while the second polarized light 102 cannot enter the image generating part 200, the first polarized light 101 is the polarized light that can be used by the image generating unit 200, and the second polarized light 102 is the polarized light that cannot be used by the image generating unit 200; the polarization axis of the polarizing layer 210 is parallel to the second polarized light In the case of the light 102, the second polarized light 102 can enter the image generating part 200 after passing through the polarizing layer 210, and the first polarized light 101 cannot enter the image generating part 200, so the second polarized light 102 can be generated by the image. The first polarized light 101 is polarized light that cannot be used by the image generation unit 200 . Thus, one of the first polarized light 101 and the second polarized light 102 can enter the image generating part 200 through the polarizing layer 210 . As shown in FIG. 1B , the image source 10 further includes a beam splitting element 300 , a direction changing element 400 and a polarization converting element 500 . For example, the beam splitting element 300 , the direction changing element 400 , and the polarization converting element 500 are all located between the light source 100 and the image generating part 200 . The beam splitting element 300 is configured to split the light emitted by the light source 100 and incident on the beam splitting element 300 into the first polarized light 101 and the second polarized light 102 . For example, the light emitted by the light source 100 is incident on the beam splitting element 300 (for example, incident on the beam splitting surface of the beam splitting element), the beam is split into two polarized lights whose polarization directions are perpendicular to each other. The first polarized light 101 described above is directed toward the image generating unit 200 , and the second polarized light 102 is directed toward the direction changing element 400 . For example, the propagation direction of the light emitted by the light source 100 before being split by the beam splitting element 300 is the same or substantially the same as the propagation direction of the first polarized light 101 , for example, both are propagated to the image generating unit 200 ; The propagation direction of the beam splitting element 300 before beam splitting is different from the propagation direction of the second polarized light 102 before being incident on the direction changing element 400 .

As shown in FIG. 1B , the direction changing element 400 is configured to change the propagation direction of the light incident on the direction changing element 400 , eg, the second polarized light 102 , to be directed toward the image generating section 200 . For example, at least part of the second polarized light 102 split by the beam splitting element 300 propagates toward the direction changing element 400 , and the direction changing element 400 can change the propagation direction of the second polarized light 102 directed to the direction changing element 400 . For example, all of the second polarized light 102 split by the beam splitting element 300 may propagate toward the direction changing element 400 .

As shown in FIG. 1B , the polarization conversion element 500 is configured to convert the polarized light whose polarization direction is not parallel to the polarization axis of the polarizing layer 210 among the first polarized light 101 and the second polarized light 102 into a polarized light having a polarization direction not parallel to the polarization axis of the polarizing layer 210 before reaching the image generating section 200 Polarized light with a polarization direction parallel to the polarization axis.

For example, polarized light with a polarization direction parallel to the polarization axis may be all polarized light with a polarization direction parallel to the polarization axis, or may be most of the light (eg, greater than 50%, 60%, 70%, 80% , 90% or 95% of the total amount of light), the polarization direction is parallel to the polarization axis.

For example, when the polarization axis of the polarizing layer 210 is parallel to the first polarized light 101 , the polarization conversion element 500 converts the second polarized light 102 split and formed by the beam splitting element 300 into the first polarization before reaching the image generating unit 200 . Light 101 ; in the case where the polarization axis of the polarizing layer 210 is parallel to the second polarized light 102 , the polarization conversion element 500 converts the first polarized light 101 split by the beam splitting element 300 into a second polarized light 101 before reaching the image generating section 200 Polarized light 102 .

For example, the first polarized light 101 or the second polarized light 102 used by the image generation unit 200 includes the polarized light obtained after one of the first polarized light 101 and the second polarized light 102 is converted by the polarization conversion element 500 , and the polarized light that is not converted by the polarization conversion element 500 . The other of the first polarized light 101 and the second polarized light 102 converted by the polarization conversion element 500 . For example, the image generating unit 200 may directly use the first polarized light 101, or may use the polarized light obtained by converting the second polarized light 102; or, the image generating unit 200 may directly use the second polarized light 102, or may use The polarized light obtained after a polarized light 101.

For example, the light source 100 may include at least one electroluminescent device that generates light through electric field excitation, such as Light Emitting Diode (LED), Organic Light-Emitting Diode (OLED), Mini LED (Mini LED) , Micro LED, Cold Cathode FluoreScent LamP (CCFL), Cold LED Light (CLL), Electro LumineScent (EL), Electron Emission (Field EmiSSion DiSPlay, FED) or quantum dot light source (Quantum Dot, QD).

For example, the image generation part 200 may include a liquid crystal display panel. FIG. 1B schematically shows that the image generating part 200 includes two

polarizing layers

210 and 220, and a structure 230 located between the two polarizing layers.

For example, the liquid crystal display panel may be a transmissive liquid crystal display panel or a reflective liquid crystal display panel.

For example, FIG. 1C is a schematic diagram of a partial structure of a liquid crystal display panel provided according to at least one embodiment of the present disclosure. As shown in FIG. 1C , the liquid crystal display panel may include an array substrate 231 , an opposite substrate 232 , a liquid crystal layer 233 between the array substrate 231 and the opposite substrate 232 , and a frame sealant 234 for encapsulating the liquid crystal layer 233 . For example, the liquid crystal display panel further includes a first polarizing layer 210 disposed on a side of the array substrate 231 away from the opposite substrate 232 and a second polarizing layer 220 disposed on a side of the opposite substrate 232 far away from the array substrate 231 . For example, the light source 100 is configured to provide the backlight BL to the liquid crystal display panel, and the backlight BL is converted into the image light IML after passing through the liquid crystal display panel.

For example, the polarization axis direction of the first polarizing layer 210 and the polarization axis direction of the second polarizing layer 220 are perpendicular to each other, but not limited thereto. For example, the first polarizing layer 210 may pass the first linearly polarized light, and the second polarizing layer 220 may pass the second linearly polarized light, but not limited thereto. For example, the polarization direction of the first linearly polarized light is perpendicular to the polarization direction of the second linearly polarized light.

For example, light with a specific polarization state may pass through the first polarizing layer 210 between the liquid crystal layer 233 and the light source 100 to be incident inside the liquid crystal display panel, and be used for imaging. For example, when the light emitted by the light source is non-polarized light, at most 50% of the light emitted by the light source can be utilized by the image generating unit, and the rest of the light will be wasted or absorbed by the liquid crystal layer to generate heat. However, in at least one embodiment of the present disclosure, by arranging a beam splitting element, a direction changing element, and a polarization converting element between the light source and the image generating unit, almost all of the unpolarized light emitted by the light source can be converted into light that can be utilized by the image generating unit. The light of a specific polarization state can effectively improve the utilization rate of the light emitted by the light source.

For example, as shown in FIG. 1B , the polarization axis of the polarizing layer 210 (for example, the above-mentioned first polarizing layer) of the image generating unit 200 is parallel to the polarization direction of the second polarized light 102 , and the image generating unit 200 can utilize the second polarizing light 102 Polarized light 102 . The beam splitting element 300 is configured to transmit the first polarized light 101 in the light source 100 and reflect the second polarized light 102 in the light source 100 to the direction changing element 400 .

For example, the beam splitting element 300 may have the function of transmitting light of one characteristic and reflecting light of another characteristic, for example, the beam splitting element 300 may have the characteristic of transmitting light of one polarization state and reflecting light of another polarization state , the beam splitting element can realize beam splitting by utilizing the above-mentioned transflective characteristics. For example, beam splitting element 300 is configured to transmit light having a first polarization greater than light having a second polarization, and/or reflect light having a second polarization greater than light having a second polarization The reflectance of light of the first polarization.

For example, the beam splitting element 300 may be a transflective film, which achieves beam splitting by transmitting part of the light and reflecting another part of the light. For example, the transflective film may transmit the first polarized light 101 in the light emitted by the light source 100 and reflect the second polarized light 102 in the light emitted by the light source 100 .

For example, the transflective film can be an optical film with polarized transflective function, which can split the unpolarized light into two optical films with mutually perpendicular polarization states through transmission and reflection; the above-mentioned optical film can be composed of multiple layers The film layers with different refractive indices are combined in a certain stacking order, and the thickness of each film layer is about 10-1000nm; the material of the film layer can be selected from inorganic dielectric materials, such as metal oxides and metal nitrides; Polymeric materials such as polypropylene, polyvinyl chloride or polyethylene can also be selected.

For example, the direction changing element 400 is configured to reflect the second polarized light 102 incident on the direction changing element 400 to the image generating section 200 .

For example, the direction changing element 400 may be a reflective element for reflecting the second polarized light 102 emitted from the beam splitting element 300 to the image generating part 200 . In the case where the polarization axis of the polarizing layer 210 of the image generating unit 200 is parallel to the polarization direction of the second polarized light 102 , the second polarized light 102 directed from the direction changing element 400 to the image generating unit 200 can be utilized by the image generating unit 200 , for example, is directly used by the image generation unit 200 .

For example, as shown in FIG. 1B , the polarization converting element 500 is located between the beam splitting element 300 and the image generating part 200 , and is configured to convert the first polarized light 101 transmitted from the beam splitting element 300 to the second polarized light 102 , The converted second polarized light 102 is directed to the image generating unit 200 to be utilized by the image generating unit 200 . For example, the polarization conversion element 500 may be a phase retardation film, and by rotating the polarization direction of the first polarized light 101 incident thereon by 90 degrees, the light emitted from the phase retardation film to the image generating part 200 can be transmitted by the image generating part 200 utilizes the second polarized light 102 .

In the image source provided by at least one embodiment of the present disclosure, a polarization conversion element is used to convert the polarized light formed after the beam splitting element that cannot be used by the image generation part into the polarized light that can be used by the image generation part, which can effectively improve the light source. The utilization of light emitted.

For example, as shown in FIG. 1B , the polarization converting element 500 is located on the side of the beam splitting element 300 away from the direction changing element 400 . For example, the beam splitting element 300 includes a first side and a second side opposite to each other, the beam splitting element 300 transmits the first polarized light 101 toward its first side, reflects the second polarized light 102 toward its second side, and converts the polarization Element 500 is located on the first side of beam splitting element 300 to convert first polarized light 101 to second polarized light 102 , and polarization converting element 500 may be located on the side of beam splitting element 300 away from direction changing element 400 .

For example, one of the first polarized light 101 and the second polarized light 102 includes light in the S polarization state, and the other of the first polarized light 101 and the second polarized light 102 includes light in the P polarization state. For example, the angle between the first polarized light 101 and the second polarized light 102 may be approximately 90°, for example, the polarization states of the first polarized light 101 and the second polarized light 102 are orthogonal to each other, for example, the first polarized light 101 and the second polarized light 102 are orthogonal to each other. The second polarized light 102 is both linearly polarized light, and the polarization directions of the two are perpendicular to each other. The embodiments of the present disclosure are not limited thereto, for example, the embodiments of the present disclosure are not limited to one of the first polarized light 101 and the second polarized light 102 including the light of the S polarization state, and the other of the first polarized light 101 and the second polarized light 102 The first polarized light 101 and the second polarized light 102 can also be non-S polarized light or non-P polarized light, and the polarization directions of the first polarized light and the second polarized light can be vertical, and/or, The polarization states of the first polarized light and the second polarized light are orthogonal. For example, the first polarized light and the second polarized light can be two linearly polarized lights with mutually orthogonal polarization directions, or two kinds of mutually orthogonal polarization states. Circularly polarized light, or two kinds of elliptically polarized light whose polarization states are orthogonal to each other, etc.

For example, the first polarized light 101 shown in FIG. 1B is the light of the P polarization state, and the second polarized light 102 is the light of the S polarization state as an example. The image generating unit 200 can utilize the light of the S-polarized state (ie, the S-polarized light), the beam splitting element 300 can reflect the S-polarized light, and transmit the light of the P-polarized state (ie, the P-polarized light), and the direction changing element 400 can reflect the S-polarized light Light. The S-polarized light in the light emitted by the light source 100 is reflected by the beam splitting element 300 to the direction changing element 400 . The P-polarized light in the light emitted by the light source 100 is transmitted through the beam splitting element 300, and after transmission, passes through the polarization conversion element 500 and is converted into S-polarized light, which realizes that the non-polarized light emitted by the light source 100 is converted into the image generator 200. S polarized light.

For example, the beam splitting element 300 may be an element formed by coating or sticking a film on a transparent substrate. For example, the beam splitting element 300 can be a transflective film with the characteristics of reflecting S-polarized light and transmitting P-polarized light, such as a reflective polarized brightness enhancement film (Dual Brightness Enhance Film, DBEF) or a prism film ( Brightness Enhancement Film, BEF) and so on. The embodiments of the present disclosure are not limited thereto, for example, the beam splitting element may also be an integrated element.

For example, the direction changing element 400 can be a common reflective plate, such as a metal or glass reflective plate; it can also be a reflective film with the characteristic of reflecting S-polarized light plated or pasted on the substrate. For example, the direction changing element 400 may also have transflective properties, and have the same transflective properties as the transflective film included in the beam splitting element 300 , such as the property of reflecting S-polarized light and transmitting P-polarized light. This embodiment of the present disclosure does not limit this, as long as the direction changing element 400 can reflect S-polarized light.

For example, the polarization conversion element 500 includes a half-wave plate.

For example, FIG. 2 is a schematic diagram of the bonding arrangement of the beam splitting element and the polarization conversion element shown in FIG. 1B . As shown in FIG. 2 , for example, the polarization conversion element 500 and the beam splitter element 300 are attached and disposed. For example, a transparent substrate 035 may be disposed between the beam splitting element 300 and the polarization conversion element 500, and the beam splitting element 300 and the polarization conversion element 500 are respectively attached to two opposite surfaces of the transparent substrate 035 for convenient arrangement. The embodiments of the present disclosure are not limited thereto, for example, the beam splitting element can also be attached to the polarization conversion element (eg, the beam splitter element is directly attached to the surface of the polarization conversion element) to achieve a light, thin and weight-reducing design of the image source.

For example, it is taken as an example that the first polarized light 101 shown in FIG. 1B is the light of the S polarization state, and the second polarized light 102 is the light of the P polarization state. The image generating unit 200 can use the light of the P polarization state (ie, the P-polarized light), the beam splitting element 300 can reflect the P-polarized light, and transmit the light of the S-polarized state (ie, the S-polarized light), and the direction changing element 400 can reflect the P polarization Light. The P-polarized light in the light emitted by the light source 100 is reflected to the direction changing element 400 by the beam splitting element 300 , and the P-polarized light reflected to the direction changing element 400 is reflected by the direction changing element 400 and then exits to the image generating unit 200 . The S-polarized light in the light emitted by the light source 100 is transmitted through the beam splitting element 300, and after transmission, passes through the polarization conversion element 500 and then converted to P-polarized light, so that the non-polarized light emitted by the light source 100 can be converted into the image generator 200. used P-polarized light. For example, the beam splitting element 300 has the property of reflecting P-polarized light and transmitting S-polarized light; the direction changing element 400 has the property of reflecting P-polarized light.

3 is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 3 , the image source 10 includes a light source 100 and an image generation unit 200 . The light source 100 and the image generation unit 200 shown in FIG. 3 may have the same features as the light source 100 and the image generation unit 200 shown in FIG. 1B , and the positional relationship between the light source 100 and the image generation unit 200 shown in FIG. 3 may be the same as that shown in FIG. 1B The illustrated positional relationship between the light source 100 and the image generating unit 200 is the same or similar, and will not be repeated here.

As shown in FIG. 3 , the image source 10 further includes a beam splitting element 300 , a direction changing element 400 and a polarization converting element 500 . The beam splitting element 300 is located between the light source 100 and the image generating part 200, and is configured to split the light incident on the beam splitting element 300 into the first polarized light 101 and the second polarized light 102, for example, the light emitted by the light source 100 After being incident on the beam splitting element 300 (eg, incident on the beam splitting surface of the beam splitting element), the beam is split into two first polarized light 101 and second polarized light 102 whose polarization directions are perpendicular to each other. The first polarized light 101 propagates to the image generating section 200 , and the second polarized light 102 propagates to the direction changing element 400 . For example, FIG. 3 schematically shows that the first polarized light 101 is directly directed toward the image generating unit 200 , and the second polarized light 102 is directed toward the direction changing element 400 , but not limited to this, the first polarized light 101 may also pass through other optical Elements, such as optical elements such as the beam condensing element 700 and the beam diffusing element 800 described later, are directed to the image generating part 200 ; for example, the second polarized light 102 can also be directed to the direction changing element 400 after passing through other optical elements. For example, the propagation direction of the light emitted by the light source 100 before being split by the beam splitting element 300 is the same as the propagation direction of the first polarized light 101 , both of which are propagated to the image generating unit 200 ; The propagation direction before beam splitting is different from the propagation direction of the second polarized light 102 before being incident on the direction changing element 400 . For example, the beam splitting element 300 shown in FIG. 3 has the same features as the beam splitting element 300 described in FIGS. 1A-2 .

For example, the above-mentioned beam splitting element may include a stereo beam splitter formed by two bonded prisms, and the beam splitting surface of the beam splitting element may refer to splitting a beam of incident light emitted by a light source into a first polarized light and a second polarized light. The bonding surface of two prisms of dipolarized light. For example, the above-mentioned beam splitting element may include a stacked structure of multiple layers of different refractive index films, and the beam splitting surface of the beam splitting element may refer to the whole of the stacked structure of multiple layers of different refractive index layers.

As shown in FIG. 3 , the direction changing element 400 is located on the side of the beam splitting element 300 facing the light source 100 , and the direction changing element 400 is configured to change the propagation direction of the second polarized light 102 incident on the direction changing element 400 so as to be directed toward Image generation unit 200 . For example, at least part of the second polarized light 102 split by the beam splitting element 300 propagates toward the direction changing element 400 , and the direction changing element 400 can change the propagation direction of the second polarized light 102 directed toward the direction changing element 400 . For example, sending the second polarized light 102 to the image generating part 200 may include that the second polarized light is sent to the image generating part 200 after passing through the polarization conversion element 500 . Of course, the second polarized light 102 may also pass through other optical elements, such as optical elements such as a beam condensing element and a beam diffusing element described later, and then go to the image generating unit.

For example, as shown in FIG. 3 , if the polarization axis of the polarizing layer 210 of the image generating unit 200 is parallel to the polarization direction of the first polarized light 101 , the image generating unit 200 can use the first polarized light 101 . The beam splitting element 300 is configured to transmit the first polarized light 101 in the light source 100 to the image generating section 200 and to reflect the second polarized light 102 in the light source 100 to the direction changing element 400.

For example, beam splitting element 300 is configured to transmit light having a first polarization greater than light having a second polarization, and/or to reflect light having a second polarization greater than The reflectance of light having the first polarization. For example, the beam splitting element 300 may be a transflective film that transmits the first polarized light 101 in the light emitted by the light source 100 and reflects the second polarized light 102 in the light emitted by the light source 100 . Since the polarization axis of the polarizing layer 210 of the image generating part 200 is parallel to the polarization direction of the first polarized light 101 , the first polarized light 101 emitted from the beam splitting element 300 to the image generating part 200 can be used by the image generating part 200 , for example It is directly used by the image generation unit 200 .

For example, as shown in FIG. 3 , the direction changing element 400 may be a reflective element for reflecting the second polarized light 102 incident on the direction changing element 400 toward the image generating part 200 .

For example, as shown in FIG. 3 , the polarization conversion element 500 is located between the direction change element 400 and the image generation part 200, and is configured to convert the second polarized light 102 reflected by the direction change element 400 into the first polarized light 101, The converted first polarized light 101 is directed to the image generating unit 200 .

For example, the polarization conversion element 500 may be a phase retardation film, such as a half-wave plate, and the polarization direction of the second polarized light 102 incident thereon may be rotated by 90 degrees so as to be directed from the phase retardation film to the image generating part The light ray 200 is the first polarized light 101 that can be used by the image generating unit 200 .

The image source provided in at least one embodiment of the present disclosure utilizes a beam splitting element, a direction changing element, and a polarization converting element to convert almost all the unpolarized light emitted by the light source into light with a specific polarization state that can be utilized by the image generating unit, which can improve the The utilization rate of the light emitted by the light source, so that the light source can provide images with higher brightness under the same power conditions.

For example, as shown in FIG. 3 , the direction changing element 400 includes a first side and a second side that are opposite to each other, and the beam splitting element 300 is located on the first side of the direction changing element 400 to provide direction change to the direction changing element 400 (eg, the direction changing element 400 ). The surface facing the beam splitting element 300 or the surface away from the beam splitting element 300) reflects the second polarized light 102; The same side of the element 400 to convert the second polarized light 102 directed to the image generating part 200 into the first polarized light 101 .

For example, one of the first polarized light 101 and the second polarized light 102 includes light in the S polarization state, and the other of the first polarized light 101 and the second polarized light 102 includes light in the P polarization state.

For example, as shown in FIG. 3 , the conversion film layer of the polarization conversion element 500 is parallel to the polarizing layer 210 , which can make the polarization conversion efficiency higher on the one hand, and make the element easy to install on the other hand.

For example, as shown in FIG. 3 , the conversion film layer of the polarization conversion element 500 is perpendicular to the main direction of propagation of the second polarized light 102 or the main optical axis propagation direction of the second polarized light 102 , which can make the polarization conversion efficiency higher.

For example, it is taken as an example that the first polarized light 101 shown in FIG. 3 is a light of the S polarization state, and the second polarized light 102 is a light of the P polarization state. The light source 100 emits non-polarized light, the image generation unit 200 can use the S-polarized light (ie S-polarized light), and the beam splitting element 300 can reflect the P-polarized light (ie P-polarized light), and transmit the S-polarized light , the direction changing element 400 can reflect P-polarized light. The S-polarized light in the light emitted by the light source 100 can be directly used by the image generating unit 200 after being transmitted by the beam splitting element 300 . The P-polarized light in the light emitted by the light source 100 is reflected to the direction changing element 400 by the beam splitting element 300, and the P-polarized light reflected to the direction changing element 400 is reflected by the direction changing element 400 and then directed to the image generating unit 200. Before reaching the image generating unit 200 , the P-polarized light directed to the image generating unit 200 is converted into S-polarized light after passing through the polarization conversion element 500 , so that the unpolarized light emitted by the light source 100 is converted into available light for the image generating unit 200 . S polarized light. For example, the beam splitting element 300 may have the same characteristics of reflecting P-polarized light and transmitting S-polarized light as the beam splitting element in the example shown in FIG. 1B ; the direction changing element 400 may be the same as that in the example shown in FIG. 1B . The direction changing element has the same property of reflecting P-polarized light.

For example, the first polarized light 101 shown in FIG. 3 is the light of the P polarization state, and the second polarized light 102 is the light of the S polarization state as an example. The light source 100 emits unpolarized light, the image generation unit 200 can use the P-polarized light (ie P-polarized light), and the beam splitter 300 can reflect the S-polarized light (ie S-polarized light), and transmit the P-polarized light , the direction changing element 400 can reflect S-polarized light. After the P-polarized light in the light emitted by the light source 100 is transmitted through the beam splitting element 300 , it can be directly used by the image generating unit 200 . The S-polarized light in the light emitted by the light source 100 is reflected to the direction changing element 400 by the beam splitting element 300 , and the S-polarized light reflected to the direction changing element 400 is reflected by the direction changing element 400 and then directed to the image generating unit 200 . Before reaching the image generating part 200, the S-polarized light directed to the image generating part 200 is converted into P-polarized light after passing through the polarization conversion element 500, so as to realize the conversion of the unpolarized light emitted by the light source 100 (for example, uniform conversion or most conversion). ) is P-polarized light usable by the image generation unit 200 . For example, the beam splitting element 300 may have the same characteristics of reflecting S-polarized light and transmitting P-polarized light as the beam splitting element in the example shown in FIG. 1B ; the direction changing element 400 may be the same as that in the example shown in FIG. 1B . The direction changing element has the same property of reflecting S-polarized light.

FIG. 4 is a schematic partial structure diagram of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 4 , the image source 10 includes a light source 100 and an image generation unit 200 . The light source 100 and the image generating unit 200 shown in FIG. 4 may have the same features as the light source 100 and the image generating unit 200 shown in FIG. 1B , and the positional relationship between the light source 100 and the image generating unit 200 shown in FIG. 4 may be the same as that shown in FIG. 1B The illustrated positional relationship between the light source 100 and the image generating unit 200 is the same, and details are not repeated here.

As shown in FIG. 4 , the image source 10 further includes a beam splitting element 300 , a direction changing element 400 and a polarization converting element 500 . The beam splitting element 300 is located between the light source 100 and the image generating unit 200 . For example, beam splitting element 300 is configured to transmit light having a first polarization greater than light having a second polarization, and/or reflect light having a second polarization greater than light having a second polarization The reflectance of light of the first polarization. For example, the beam splitting element 300 is configured to split light incident on the beam splitting element 300 into the first polarized light 101 and the second polarized light 102 . For example, after the light emitted by the light source 100 is incident on the beam splitting element 300 (for example, incident on the beam splitting surface of the beam splitting element), it is split into two first polarized light 101 and second polarized light 102 whose polarization directions are perpendicular to each other. . The first polarized light 101 propagates to the image generating section 200 , and the second polarized light 102 propagates to the direction changing element 400 . For example, FIG. 4 schematically shows that the first polarized light 101 is directly directed toward the image generating unit 200 , and the second polarized light 102 is directed toward the direction changing element 400 after passing through the polarization conversion element 500 , but not limited to this, the first polarized light 101 It can also pass through other optical elements, such as the optical elements such as the beam condensing element 700 and the beam diffusing element 800 described later, and then go to the image generating part 200; for example, the second polarized light 102 can also pass through other optical elements and then go to the direction changing element. 400. For example, the propagation direction of the light emitted by the light source 100 before being split by the beam splitting element 300 is the same as the propagation direction of the first polarized light 101 , for example, both are propagated to the image generating unit 200 ; The propagation direction before 300 beam splitting is different from the propagation direction of the second polarized light 102 before being incident on the direction changing element 400 . For example, the beam splitting element 300 shown in FIG. 4 has the same features as the beam splitting element 300 described in FIGS. 1A-2 .

As shown in FIG. 4 , the direction changing element 400 is located on the side of the beam splitting element 300 facing the light source 100 , and the direction changing element 400 is configured to change the propagation direction of the polarized light incident on the direction changing element 400 to be directed toward the image generating section 200. For example, at least part of the second polarized light 102 split by the beam splitting element 300 propagates toward the direction changing element 400 , and the direction changing element 400 can change the propagation direction of the second polarized light 102 directed to the direction changing element 400 . For example, the above-mentioned second polarized light 102 directed to the image generating unit 200 may include that the second polarized light is directed to the image generating unit after passing through other optical elements, such as optical elements such as a beam converging element and a beam diffusing element described later.

For example, as shown in FIG. 4 , the polarization axis of the polarizing layer 210 of the image generating unit 200 is parallel to the polarization direction of the first polarized light 101 , and the image generating unit 200 can use the first polarized light 101 . The beam splitting element 300 is configured to transmit the first polarized light 101 in the light source 100 to the image generating section 200 , and to reflect the second polarized light 102 in the light source 100 toward the direction changing element 400 .

For example, the beam splitting element 300 may be a transflective film that transmits the first polarized light 101 in the light emitted by the light source 100 and reflects the second polarized light 102 in the light emitted by the light source 100 . Since the polarization axis of the polarizing layer 210 of the image generating unit 200 is parallel to the polarization direction of the first polarized light 101 , the first polarized light 101 emitted from the beam splitting element 300 to the image generating unit 200 can be directly utilized by the image generating unit 200 .

For example, as shown in FIG. 4, the polarization conversion element 500 is located between the direction changing element 400 and the beam splitting element 300, and is configured to convert the second polarized light 102 reflected from the beam splitting element 300 toward the direction changing element 400 into a second polarized light 102 A polarized light 101 , and the direction changing element 400 is configured to reflect the converted first polarized light 101 to the image generating section 200 .

For example, the polarization conversion element 500 may be a phase retardation film, such as a half-wave plate, and the polarization direction of the second polarized light 102 incident thereon may be rotated by 90 degrees so that the direction changing element 400 is transmitted from the phase retardation film by 90 degrees. The light beam directed to the image generation unit 200 is the first polarized light 101 that can be utilized by the image generation unit 200 .

In at least one embodiment of the present disclosure, the polarization conversion element located between the beam splitting element and the direction changing element can convert the second polarized light emitted from the beam splitting element to the first polarized light before incident on the direction changing element, and after the conversion When the first polarized light is reflected to the image generating part by the direction changing element, the polarization direction is no longer converted by the polarization converting element.

For example, as shown in FIG. 4 , the polarization converting element 500 may be a planar sheet (eg, may be a parallel planar sheet with opposing major surfaces that are substantially parallel), and the planar sheet may be perpendicular to the polarizing layer 210 . For example, the propagation direction of the second polarized light 102 incident on the polarization conversion element 500 may be perpendicular or nearly perpendicular to the polarization conversion element 500 .

For example, the first polarized light 101 shown in FIG. 4 is the light of the S polarization state, and the second polarized light 102 is the light of the P polarization state as an example. The light source 100 emits non-polarized light, the image generation unit 200 can use the S-polarized light (ie S-polarized light), and the beam splitting element 300 can reflect the P-polarized light (ie P-polarized light), and transmit the S-polarized light , the direction changing element 400 can reflect S-polarized light. The S-polarized light in the light emitted by the light source 100 can be directly used by the image generating unit 200 after being transmitted by the beam splitting element 300 . The P-polarized light in the light emitted by the light source 100 is reflected to the direction changing element 400 by the beam splitting element 300, and the P-polarized light reflected to the direction changing element 400 is converted into S-polarized light after passing through the polarization converting element 500 before reaching the direction changing element 400. , the converted S-polarized light is reflected to the image generating unit through the direction changing element 400 , so that the unpolarized light emitted by the light source 100 is converted into S-polarized light usable by the image generating unit 200 . For example, the beam splitting element 300 may have the same characteristics of reflecting P-polarized light and transmitting S-polarized light as the beam splitting element in the example shown in FIG. 1B ; the direction changing element 400 may be the same as that in the example shown in FIG. 1B . The direction changing element has the same property of reflecting S-polarized light.

For example, the first polarized light 101 shown in FIG. 4 is the light of the P polarization state, and the second polarized light 102 is the light of the S polarization state as an example. The light source 100 emits unpolarized light, the image generation unit 200 can use the P-polarized light (ie P-polarized light), and the beam splitter 300 can reflect the S-polarized light (ie S-polarized light), and transmit the P-polarized light , the direction changing element 400 can reflect P-polarized light. After the P-polarized light in the light emitted by the light source 100 is transmitted through the beam splitting element 300 , it can be directly used by the image generating unit 200 . The S-polarized light in the light emitted by the light source 100 is reflected to the direction changing element 400 by the beam splitting element 300, and the S-polarized light reflected to the direction changing element 400 is converted into P-polarized light after passing through the polarization converting element 500 before reaching the direction changing element 400. , the converted P-polarized light is reflected to the image generating unit 200 by the direction changing element 400 , realizing the conversion (eg, both conversion) of the unpolarized light emitted by the light source 100 into P-polarized light usable by the image generating unit 200 . For example, the beam splitting element 300 may have the same characteristics of reflecting S-polarized light and transmitting P-polarized light as the beam splitting element in the example shown in FIG. 1B ; the direction changing element 400 may be the same as that in the example shown in FIG. 1B . The direction changing element has the same property of reflecting P-polarized light.

FIG. 5 is a schematic partial structure diagram of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 5 , the image source 10 includes a light source 100 and an image generation unit 200 . The light source 100 and the image generating unit 200 shown in FIG. 5 may have the same features as the light source 100 and the image generating unit 200 shown in FIG. 1B , and the positional relationship between the light source 100 and the image generating unit 200 shown in FIG. 4 may be the same as that shown in FIG. 1B The illustrated positional relationship between the light source 100 and the image generating unit 200 is the same, and details are not repeated here.

As shown in FIG. 5 , the image source 10 further includes a beam splitting element 300 , a direction changing element 400 and a polarization converting element 500 . The beam splitting element 300 is located between the light source 100 and the image generating unit 200 . For example, beam splitting element 300 is configured to transmit light having a first polarization greater than light having a second polarization, and/or reflect light having a second polarization greater than light having a second polarization The reflectance of light of the first polarization. For example, the beam splitting element 300 is configured to split light incident on the beam splitting element 300 into the first polarized light 101 and the second polarized light 102 . For example, after the light emitted by the light source 100 is incident on the beam splitting element 300 (for example, incident on the beam splitting surface of the beam splitting element), it is split into two first polarized light 101 and second polarized light 102 whose polarization directions are perpendicular to each other. . The first polarized light 101 is directed toward the image generating section 200 , and the second polarized light 102 is directed toward the direction changing element 400 . For example, the propagation direction of the light emitted by the light source 100 before being split by the beam splitting element 300 is the same as the propagation direction of the first polarized light 101, and propagates to the image generating unit 200, for example, to the image generating unit 200; The propagation direction of the light ray before being split by the beam splitting element 300 is different from the propagation direction of the second polarized light 102 before it is incident on the direction changing element 400 .

As shown in FIG. 5 , the direction changing element 400 is located on the side of the beam splitting element 300 facing the light source 100 , and the direction changing element 400 is configured to change the propagation direction of the polarized light incident on the direction changing element 400 so as to be directed toward the image generating section 200. For example, at least part of the second polarized light 102 split by the beam splitting element 300 propagates toward the direction changing element 400 , and the direction changing element 400 can change the propagation direction of the second polarized light 102 directed to the direction changing element 400 . For example, the above-mentioned light rays whose propagation direction is changed by the direction changing element and then directed to the image generating part may pass through the polarization conversion element and then be directed to the image generating part, and of course may also pass through other optical elements, such as the beam condensing element 700 and the beam diffusing element described later. 800 and other optical elements are then directed to the image generation unit.

For example, as shown in FIG. 5 , if the polarization axis of the polarizing layer 210 of the image generating unit 200 is parallel to the polarization direction of the first polarized light 101 , the image generating unit 200 can use the first polarized light 101 . The beam splitting element 300 is configured to transmit the first polarized light 101 in the light source 100 to the image generating section 200 , and to reflect the second polarized light 102 in the light source 100 toward the direction changing element 400 .

For example, the beam splitting element 300 may be a transflective film that transmits the first polarized light 101 in the light emitted by the light source 100 and reflects the second polarized light 102 in the light emitted by the light source 100 . Since the polarization axis of the polarizing layer 210 of the image generating part 200 is parallel to the polarization direction of the first polarized light 101 , the first polarized light 101 emitted from the beam splitting element 300 to the image generating part 200 can be used by the image generating part 200 , for example It is directly used by the image generation unit 200 .

For example, as shown in FIG. 5, the polarization conversion element 500 is located between the direction changing element 400 and the beam splitting element 300, and is configured to convert the second polarized light 102 reflected from the beam splitting element 300 toward the direction changing element 400 into a second polarized light 102 Three polarized lights 103 . The third polarized light 103 is reflected by the direction changing element 400 and converted into the first polarized light 101 after passing through the polarization conversion element 500 , and the converted first polarized light 101 is directed to the image generating unit 200 .

For example, the polarization conversion element 500 can be a phase retardation film, such as a quarter-wave plate, and can convert the second polarized light 102, such as linearly polarized light, incident thereon into a third polarized light 103, such as circularly polarized light Or elliptically polarized light, so that the polarized light incident on the direction changing element 400 after passing through the phase retardation film is no longer linearly polarized light. The third polarized light 103 incident on the direction changing element 400 is changed in the direction of propagation by the direction changing element 400 to propagate toward the image generation part 200 , and the third polarized light 103 before reaching the image generation part 200 passes through the polarization conversion element 500 again to It is converted into the first polarized light 101 that can be used by the image generation unit 200 .

As shown in FIG. 1A to FIG. 5 , the direction changing element is located outside or in the optical path where the polarization conversion element is located, wherein the polarized light that is not converted by the polarization conversion element in the first polarized light and the second polarized light is changed in direction. After the element is processed, it is used by the image generation part; or, after one of the first polarized light and the second polarized light is processed by the direction changing element, it is converted into the polarized light that can be used by the image generation part through the polarization conversion element; One of the polarized light and the second polarized light is converted by the polarization conversion element into polarized light that can be used by the image generation unit, and then processed by the direction change element; or one of the first polarized light and the second polarized light After the first conversion by the polarization conversion element, after being processed by the direction changing element, and after the second conversion by the polarization conversion element, it is converted into polarized light that can be used by the image generating unit.

In at least one embodiment of the present disclosure, the polarization conversion element located between the beam splitting element and the direction changing element can convert the second polarized light emitted from the beam splitting element to the third polarized light before incident on the direction changing element, and after the conversion During the process of being reflected by the direction changing element toward the image generating part, the third polarized light of the 1 passes through the polarization converting element again to be converted into the first polarized light, and the converted first polarized light propagates toward the image generating part.

In at least one embodiment of the present disclosure, by arranging a beam splitting element, a direction changing element, and a polarization converting element between the light source and the image generating unit, almost all of the unpolarized light emitted by the light source can be converted into specific light that can be utilized by the image generating unit. The polarized light can effectively improve the utilization rate of the light emitted by the light source.

For example, as shown in FIG. 5 , the number of polarization conversion elements 500 may be one, then the third polarized light 103 incident on the direction changing element 400 and the third polarized light 103 reflected from the direction changing element 400 pass through (for example, both through) the same polarization conversion element 500. At least one embodiment of the present disclosure is not limited thereto. For example, the number of polarization conversion elements may also be two, and the third polarized light incident on the direction changing element and the third polarized light reflected from the direction changing element undergo different polarization conversions. component, the third polarized light can be converted into the first polarized light through the polarization conversion element.

For example, a transparent substrate may be disposed between the direction changing element 400 and the polarization converting element 500, and the direction changing element 400 and the polarization converting element 500 are respectively attached to two surfaces of the transparent substrate opposite to each other for convenient arrangement.

For example, it is taken as an example that the first polarized light 101 shown in FIG. 5 is a light of the S-polarized state, and the second polarized light 102 is a light of the P-polarized state. The light source 100 emits non-polarized light, the image generation unit 200 can use the S-polarized light (ie S-polarized light), and the beam splitting element 300 can reflect the P-polarized light (ie P-polarized light), and transmit the S-polarized light , the direction changing element 400 can reflect circularly polarized light. The S-polarized light in the light emitted by the light source 100 can be directly used by the image generating unit 200 after being transmitted by the beam splitting element 300 . The P-polarized light in the light emitted by the light source 100 is reflected to the direction changing element 400 by the beam splitting element 300, and the P-polarized light reflected to the direction changing element 400 is converted into circularly polarized light after passing through the polarization converting element 500 before reaching the direction changing element 400. , the converted circularly polarized light is reflected by the direction changing element 400 and then converted into S polarized light after passing through the polarization conversion element 500 again, and the converted S polarized light is sent to the image generating part 200, realizing the unpolarized light emitted by the light source 100. It is converted into (for example, both are converted into) S-polarized light usable by the image generation unit 200 . For example, the beam splitting element 300 may have the same characteristics of reflecting P-polarized light and transmitting S-polarized light as the beam splitting element in the example shown in FIG. 1B ; the direction changing element 400 has the characteristics of reflecting circularly polarized light. The above-mentioned converted S-polarized light directed to the image generating unit 200 may include that the converted S-polarized light does not pass through other optical elements, but directly hits the image generating unit 200; it may also include that the converted S-polarized light passes through other optical elements, such as Optical elements such as a beam condensing element and a beam diffusing element, which will be described later, are directed to the image generating section.

For example, the first polarized light 101 shown in FIG. 5 is a light of the P polarization state, and the second polarized light 102 is a light of the S polarization state as an example. The light source 100 emits unpolarized light, the image generation unit 200 can use the P-polarized light (ie P-polarized light), and the beam splitter 300 can reflect the S-polarized light (ie S-polarized light), and transmit the P-polarized light , the direction changing element 400 can reflect circularly polarized light. After the P-polarized light in the light emitted by the light source 100 is transmitted through the beam splitting element 300 , it can be directly used by the image generating unit 200 . The S-polarized light in the light emitted by the light source 100 is reflected to the direction changing element 400 by the beam splitting element 300, and the S-polarized light reflected to the direction changing element 400 is converted into circularly polarized light after passing through the polarization converting element 500 before reaching the direction changing element 400. , the converted circularly polarized light is reflected by the direction changing element 400 and then converted into P polarized light after passing through the polarization conversion element 500 again. Converted (eg, both converted) into P-polarized light usable by the image generation unit 200 . For example, the beam splitting element 300 may be a structure having the same characteristics of reflecting S-polarized light and transmitting P-polarized light as the beam splitting element in the example shown in FIG. 1B . For example, the direction changing element 400 in this example is different from the materials shown in FIGS. 1A to 4 , and has the property of reflecting circularly polarized light, which can also be considered as having a nearly reflective effect on the first polarized light 101 and the second polarized light 102 . No difference, for example, the direction changing element 400 may utilize a metal reflective surface, such as an aluminum, silver or copper plated reflective surface.

For example, as shown in FIGS. 1B to 5 , the image source 10 may include a plurality of light sources 100 and one image generation part 200 corresponding to the plurality of light sources 100 . For example, the image source 10 may include a plurality of beam splitting elements 300 , a plurality of direction changing elements 400 and a plurality of polarization conversion elements 500 , and a light source 100 , a beam splitting element 300 , a direction changing element 400 and a polarization conversion element 500 are constituted One unit group and a plurality of unit groups correspond to one image generation unit 200 .

For example, as shown in FIGS. 1A to 5 , the image source 10 includes a plurality of light conversion parts 345 , and each light conversion part 345 includes a beam splitting element 300 , a direction changing element 400 and a polarization conversion element 500 , and the light source 100 There are multiple light sources 100 and multiple light conversion parts 345 in one-to-one correspondence, and the light emitted by each light source 100 passes through a corresponding light conversion part 345 and then goes to the image generation part 200 . In the embodiment of the present disclosure, the one-to-one arrangement of the plurality of light sources and the plurality of light conversion parts not only facilitates the disassembly and assembly of the light sources and the light conversion parts, but also facilitates adjustment and control of the outgoing light, and makes the light emitted by the light source has a high utilization rate.

For example, as shown in FIGS. 1B to 5 , the direction changing element 400 is located on the side of the beam splitting element 300 facing the light source 100 , and the beam splitting surface of the beam splitting element 300 is parallel to the reflecting surface of the direction changing element 400 . For example, the propagation direction of the light emitted by the light source 100 is parallel to the beam splitting surface of the beam splitting element 300, so that the first polarized light 101 transmitted from the beam splitting element 300 and the polarized light whose propagation direction is changed by the direction changing element 400 are The directions of propagation are parallel, whereby the light rays emerging from the beam splitting element and the direction changing element are collimated or nearly collimated. For example, the angle between the polarizing layer 210 and the beam splitting surface of the beam splitting element 300 may be 43°˜47°, or 40°˜50°, for example, the angle between the polarizing layer 210 and the beam splitting surface of the beam splitting element 300 The angle between them is approximately 45°. The collimated light can be parallel or nearly parallel light, which has the characteristics of small divergence angle and uniform brightness. The utilization rate is higher, so that more light can be converted into image light through the liquid crystal layer, the brightness of the light emitted by the image source is uniform, and the light conversion rate is high. The reflective surface of the above-mentioned direction changing element refers to a surface that reflects the polarized light radiated from the beam splitting element toward the direction changing element.

For example, as shown in FIGS. 1B to 5 , the included angle between the propagation directions of the first polarized light 101 transmitted by the beam splitting element 300 and the reflected second polarized light 102 is approximately 90°.

6 and 7 are schematic diagrams of partial structures of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIGS. 6 and 7 , the beam splitting surface of the beam splitting element 300 and the reflection surface of the direction changing element 400 have a non-zero included angle. For example, the beam splitting surface of the beam splitting element 300 and the reflection surface of the direction changing element 400 are not parallel, and the included angle between the two may be 10°˜30°. In at least one embodiment of the present disclosure, by adjusting the angle between the beam splitting element and the direction changing element, the polarized light transmitted from the beam splitting element and the polarized light reflected by the direction changing element can form a diffused light beam or a concentrated light beam .

For example, the image source 10 further includes a reflective light guide element 600 , a beam condensing element 700 and a beam diffusing element 800 .

8A to 8C are schematic structural diagrams of different reflective light guide elements provided according to at least one embodiment of the present disclosure. As shown in FIGS. 8A to 8C , the reflective light guide element 600 is disposed in the light exit direction of the light source 100 , and the light emitted by the light source 100 propagates in the reflective light guide element 600 and then exits to the beam splitting element.

For example, as shown in FIG. 8A , the inner surface of the reflective light guide element 600 is provided with a reflective surface, and the large-angle light emitted by the light source 100 will be concentrated after being reflected by the reflective surface, thereby improving the utilization rate of the light emitted by the light source 100 . For example, a hollow housing with a reflective surface can be arranged inside the reflective light guide element 600, and the housing includes an end for arranging the light source 100 and a light emitting surface 601 for emitting light, and the shape of the housing can be a triangular pyramid shape , quadrangular pyramid shape, paraboloid shape or free-form surface shape. For example, after being reflected by the reflective surface of the reflective light guide element 600 , the large-angle light rays emitted by the light source 100 are adjusted to be collimated or nearly collimated and parallel to be emitted from the light emitting surface 601 . For example, the divergence angle of the large-angle light emitted by the light source 100 is greater than 15, 30, 45 or 60 degrees, for example. For example, the divergence angle refers to the angle between the luminous direction and the axial direction when the luminous intensity value emitted by the light source is half (for example, 60%, 80%, etc.) of the intensity value of the axial ray (for example, the central ray) 2 times; alternatively, it can also be considered as the angle between the diverging rays and the central rays, or it can be 2 times the angle between the diverging rays and the central rays.

For example, as shown in FIG. 8B , the reflective light guide element 600 may include a solid transparent part, the solid transparent part includes an end 630 where the light source 100 is disposed, and the refractive index of the transparent part is greater than 1, so that part of the light emitted by the light source 100 is transparent in the solid part The internal reflection surface of the component is totally reflected and then exits, and another part of the light emitted by the light source 100 is transmitted and exited in the transparent component. For example, the end 630 of the solid transparent component where the light source 100 is disposed is provided with a cavity 620, and the side of the cavity 620 close to the light emitting surface 601 is provided with a collimating portion 610 that can adjust the light emitted by the light source 100 to parallel light. For example, the internal reflection surface of the solid transparent member may be the inner surface of the solid transparent member, and the shape of the inner surface may be a curved shape, for example, may include a parabolic shape or a free-form surface shape.

For example, as shown in FIG. 8C , the reflective light guide element 600 may include a solid transparent member, the end portion 630 of the solid transparent member provided with the light source 100 is provided with a cavity 620 , and the light emitting surface 601 of the solid transparent member is provided with a cavity 620 extending toward the end portion 630 . The bottom surface of the opening 602 close to the end portion 630 is provided with a collimating portion 610 that can adjust the light emitted by the light source 100 into parallel light.

For example, FIG. 9 is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 9 , at least a part of the reflective light guide element 600 is located between the light source 100 and the beam splitting element 300 , and the reflective light guide element 600 is configured to reflect the light emitted by the light source 100 so that the light emitted from the reflective light guide element 600 is reflected from the light source 100 . Outgoing rays are collimated rays. FIG. 9 schematically takes the image source including the reflective light guide element shown in FIG. 8A as an example, but it is not limited thereto, and the image source may also include the reflective light guide element shown in FIG. 8B or FIG. 8C .

For example, FIG. 10 is a schematic structural diagram of a beam condensing element provided according to at least one embodiment of the present disclosure, and FIG. 11 is a schematic diagram of an optical path of a combination of a beam condensing element and a beam diffusing element provided according to at least one embodiment of the present disclosure. As shown in FIG. 10 , the beam condensing element 700 is configured to control the direction of the light 701 emitted from the beam splitting element 300 and the direction changing element 400, for example, to focus the light 702 emitted from the beam condensing element 700 to a certain range, for example, The observation range of the image source to further gather the light and improve the utilization of light.

For example, the light beam converging element 700 can include a lens or a lens combination, such as a Fresnel lens or a spherical lens; For example, the above-mentioned certain range may be a point, such as the focal point of a convex lens, or an area with a smaller area. Setting the light beam converging element in the image source can further condense the large-angle light emitted by the light source and improve the light utilization rate.

For example, as shown in FIG. 11 , the beam diffusing element 800 diffuses the incident beam 702 and can precisely control the degree of diffusion of the incident beam 702 . The optical axis OA of the diffused beam 801 and the optical axis of the incident beam 702 are located on the same straight line Above, it can be considered that the optical axis of the light beam passing through the light beam diffusing element 800 is unchanged, and the edge rays of the diffused light beam 801 are spread out by a certain angle along the optical axis thereof. The above-mentioned "optical axis" refers to the center line of the light beam.

For example, the diffusion angle β1 of the diffused light beam 801 in the first direction may be in the range of 5°˜20°, the diffusion angle β2 in the second direction may be in the range of 5°˜10°, and the diffusion angle may refer to the luminous intensity value. 2 times the angle between the light-emitting direction and the axial direction when the intensity value of the axial ray (for example, the central ray) is half (for example, 60%, 80%, etc.), or it can also refer to the two maximum diffusion axes the angle between. For example, after the incident light beam 702 passes through the beam diffusing element 800, the cross-sectional spot of the light beam along the propagation direction may be a rectangle, the first direction is the extension direction of the long side of the rectangle, and the second direction is the extension direction of the short side of the rectangle, then the first direction is the extension direction of the rectangle. The diffusion angle of the direction refers to the included angle β1 between the light rays connected to the two ends of the long side of the rectangular light spot, and the above-mentioned diffusion angle of the second direction refers to the included angle β2 of the light rays connected to the two ends of the short side of the rectangular light spot. For example, after the light beam passes through the beam diffusion structure, when the cross-sectional shape of the light beam along the propagation direction is circular, the diffusion angle is the angle between the light beam at the edge of the circular cross-section and the optical axis, and the diffusion angle in each direction is the same. The spread angles are all the same. The cross-sectional shape of the beam can refer to the cross-section obtained by cutting the light exiting the beam-diffusing element using a plane perpendicular to the centerline of the beam or the main transmission axis, and the cross-section of the beam can be considered to be perpendicular to the centerline of the beam (eg, the axial direction) .

For example, after the incident beam 702 passes through the beam diffusing element 800, it is diffused into a beam with a specific size and shape along the propagation direction, and the energy distribution is uniform or nearly uniform, and the size and shape of the cross-section (eg, spot) of the diffused beam The shape of the light spot can include, but is not limited to, line, circle, ellipse, square, and rectangle, which can be controlled by the microstructure of the surface design of the beam diffusing element 800 . For example, the propagation angle and spot size of the diffused beam determine the brightness and visible area of the final image. The smaller the diffusion angle, the higher the imaging brightness and the smaller the visible area; and vice versa.

For example, the beam diffusing element 800 can be a scattering optical element with low cost, such as a light homogenizer, a diffuser, etc. When the light beam passes through the scattering optical element such as a light homogenizer, scattering will occur, and a small amount of diffraction will also occur. The main function is that the light beam will form a larger spot after passing through the scattering optical element.

For example, the beam diffusing element 800 may also be a diffractive optical element (Diffractive Optical Elements, DOE) that controls the diffusing effect more precisely, such as a beam shaper (Beam Shaper). For example, by designing specific microstructures on the surface of a diffractive optical element, it can expand the beam of light through diffraction, and the light spot is small, and the size and shape of the light spot are controllable.

For example, FIG. 12A is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 12A , the light beam condensing element 700 may be located between the direction changing element 400 and the beam splitting element 500 and the image generating part 200, and is configured to beam and split the light rays that are directed from the direction changing element 400 to the image generating part 200 The light rays emitted by the element 300 to the image generating unit 200 are converged.

For example, as shown in FIG. 12A , the beam diffusing element 800 is located between the beam condensing element 700 and the image generating part 200, and is configured to diffuse the light condensed by the beam condensing element 700 so that the image light emitted from the image source is diffused to The predetermined area, for example, the predetermined area may be the first predetermined area mentioned later, for example, the predetermined area may include the eye box area mentioned later.

For example, FIG. 12B is a schematic diagram of a partial structure of an image source provided according to at least one example of an embodiment of the present disclosure. As shown in FIG. 12B , the difference from the example shown in FIG. 12A is that the beam spreading element 800 in this example includes a first beam spreading element 801 and a second beam spreading element 802 , and the first beam spreading element 801 is located at the beam condensing element 700 Between the image generating unit 200 , the second light beam diffusing element 802 is located between the reflective light guiding element 600 and the beam splitting element 300 , which can more uniformly diffuse the light emitted by the light source 100 . For example, the distance between the first beam diffusing element 801 and the second beam diffusing element 802 may be 30˜50 mm.

FIG. 13 is a partial structural schematic diagram of a head-up display provided according to at least one embodiment of the present disclosure. As shown in FIG. 13 , the head-up display includes the image source 10 provided in any of the examples shown in FIGS. 1A to 12B and a reflection imaging part 20 located on the light-emitting side of the image source 10 , and the reflection imaging part 20 is configured to emit the image source 10 The light reflected to the viewing area 30 transmits ambient light. A user located in the observation area 30 can view the image 40 imaged by the image source 10 reflected by the reflective imaging part 20 and the environmental scene located on the side of the reflective imaging part 20 away from the observation area 30 . For example, the image light emitted by the image source 10 is incident on the reflective imaging part 20, and the light reflected by the reflective imaging part 20 is incident on the user, such as the observation area 30 where the driver's eyes are located, and the user can observe the image formed on the outside of the reflective imaging part, for example. (eg, the side away from the user) without affecting the user's view of the external environment.

For example, the above-mentioned observation area 30 may be an eyebox area, and the eyebox area refers to an area where the user's eyes are located and where the image displayed by the head-up display can be viewed, such as a flat area. For example, when the user's eyes deviate from the center of the eye box area by a certain distance, such as moving up and down, left and right for a certain distance, the user's eyes are in the eye box area, and the user can still see the image displayed by the head-up display.

For example, the reflective imaging part 20 may be a windshield or an imaging window of a motor vehicle, corresponding to a windshield head-up display (Windshield-HUD, W-HUD) and a combined head-up display (C-HUD), respectively.

For example, after the light emitted by the light source 100 in the image source 10 passes through the beam condensing element 700 and the beam diffusing element 800 , the light emitted by the image source 10 reaches the first predetermined area (for example, the predetermined area above) after being reflected by the reflection imaging part 20 ), the first predetermined area refers to a plane observation area, and most of the light is collected in the first predetermined area (for example, more than 90% of the light intensity of the light beam incident on the plane where the first predetermined area is located is collected in the first predetermined area). In a predetermined area, more than 80% of the light intensity of the light beams incident on the plane where the first predetermined area is located is concentrated in the first predetermined area, or more than 60% of the light beams incident on the plane where the first predetermined area is located The strong light is concentrated in the first predetermined area), and the light incident on the first predetermined area spreads throughout the first predetermined area. In the case where the light beam diffusing element 800 is removed from the optical path of the image source 10 , the light emitted by the image source 10 reaches the second predetermined area within the first predetermined area after being reflected by the reflection imaging unit 20 . For example, the second predetermined area may be a small area. For example, the second predetermined area may be a point. For example, the second predetermined area may be a certain range in which the light beam condensing element 700 described above collects light. For example, the first predetermined area may include an eyebox area, such as the observation area 30, and the second predetermined area may be a small area in the observation area 30, such as a point, such as the center. Therefore, by arranging a beam diffusing element in the image source, it can be ensured that the image light incident on the observation area at least completely covers the observation area, and the normal observation is not affected while achieving high light efficiency.

For example, FIG. 14 is a schematic partial structural diagram of a head-up display provided according to another example of at least one embodiment of the present disclosure. As shown in FIG. 14 , the reflection imaging part 20 includes a first layer 20-1, a second layer 20-2, and a gap between the first layer 20-1 and the second layer 20-2 (hereinafter referred to as an interlayer) ; the wedge-shaped film 21 is located in the interlayer of the reflective imaging part 20 (ie, the gap between the first layer 20-1 and the second layer 20-2).

The reflective imaging portion 20 provided with the wedge-shaped film 21 and the head-up display shown in FIG. 14 having an anti-ghosting function will be exemplified by taking the reflective imaging portion 20 implemented as a windshield of a vehicle (eg, a front windshield). For example, the windshield adopts a double-layer glass structure, and a wedge-shaped polyvinyl butyral (PVB) layer is embedded between the two layers of glass using a special process. The windshield can make the images reflected from the inner and outer surfaces of the glass (ie, the image reflected by the first layer 20-1 and the image reflected by the second layer 20-2) overlap into one image, thereby enabling the head-up display to have ghosting suppression (eg, anti-ghosting) function. For example, the wedge-shaped film 21 has a thin end and a thick end, and also has a certain angle, and the angle of the wedge-shaped film 21 needs to be set according to the requirements of the head-up display. In at least one embodiment of the present disclosure, by arranging a wedge-shaped film on the reflective imaging part, images reflected from the surfaces of the reflective imaging part close to the image source and away from the image source can be overlapped into one image to at least improve or solve the ghosting problem.

For example, FIG. 15 is a schematic partial structural diagram of a head-up display provided according to another example of at least one embodiment of the present disclosure. As shown in FIG. 15 , the surface of the reflection imaging part 20 facing the image source 10 is provided with a selective reflection film 22 , a P-polarized light reflection film 22 or a first retardation part 22 .

For example, the surface of the reflective imaging part 20 facing the image source 10 is provided with a selective reflection film 22, and the selective reflection film 22 is configured so that the reflectivity of the wavelength band where the image light emitted from the image generating part is located is greater than that of the wavelength band other than the wavelength band where the image light is located. reflectivity of light. For example, the reflectivity of the selective reflection film 22 to the wavelength band of the image light emitted by the image generating part may be greater than 80%, 90%, 95%, 99.5% or other applicable values. For example, the reflectivity of the selective reflection film 22 to light in wavelength bands other than the wavelength band where the image light is located may be less than 30%, 20%, 10%, 5%, 1%, 0.5% or other applicable values.

For example, the selective reflection film 22 is configured to reflect the image light emitted by the image generating unit 200 and transmit light in a wavelength band other than the wavelength band where the image light is located. For example, the selective reflection film 22 reflects the image light emitted by the image generating unit 200. If the image light includes light in three wavelength bands of red, green and blue (RGB), the selective reflection film 22 reflects the light in the three wavelength bands of RGB and transmits other light in the three wavelength bands. wavelengths of light. In this way, the image light will not be reflected twice on the surface of the reflective imaging part away from the image source, thereby improving or eliminating ghosting.

For example, the above-mentioned selective reflection film 22 may include a selective transflective film formed by stacking inorganic oxide films or polymer films, and the transflective film is formed by stacking at least two film layers with different refractive indices. The "different refractive index" here means that the refractive index of the film layer is different in at least one of the three directions of xyz. For example, by pre-selecting required film layers with different refractive indices, and stacking the film layers in a preset order, a transflective film with selective reflection and selective transmission characteristics can be formed, which can selectively reflect certain Light of one characteristic, light passing through another. For example, for a film using an inorganic oxide material, the composition of the film is selected from the group consisting of tantalum pentoxide, titanium dioxide, magnesium oxide, zinc oxide, zirconium oxide, silicon dioxide, magnesium fluoride, silicon nitride, silicon oxynitride , one or more of aluminum fluoride. For example, for a film layer using an organic polymer material, the film layer of the organic polymer material includes at least two thermoplastic organic polymer film layers. For example, two thermoplastic polymer film layers are alternately arranged to form an optical film, and the two thermoplastic polymer film layers have different refractive indices. For example, the molecules of the above organic polymer materials are chain-like structures. After stretching, the molecules are arranged in a certain direction, resulting in different refractive indices in different directions. The desired thin film can be formed through a specific stretching process. For example, the above thermoplastic polymer can be polyethylene terephthalate (PET) and its derivatives with different degrees of polymerization, polyethylene naphthalate (PEN) and its derivatives with different degrees of polymerization, degree of polybutylene terephthalate (PBT) and its derivatives.

For example, the surface of the reflective imaging part 20 facing the image source 10 is provided with a P-polarized light reflective film 22 so that the reflective image generating part 200 emits the light of the P-polarized state of the reflective imaging part 20, The reflectivity of light is greater than the reflectivity of light in the S polarization state.

For example, the image light emitted by the image source 10 includes P-polarized light, and the P-polarized reflective film 22 is provided on the surface of the reflective imaging portion 20 so that the P-polarized image light is reflected by the P-polarized reflective film 22 and then enters the observation area. 30. For example, when the material of the reflective imaging part 20 includes glass, the transmittance of the glass to P-polarized light is high, and the reflectivity is low. Except for the P-polarized light reflected by the P-polarized light reflective film 22, the P-polarized light transmitted through the glass The brightness reflected by the outer surface of the reflected imaging part 20 toward the observation area 30 is very low, so that ghosting can be improved or eliminated.

For example, the structure of the P-polarized light reflective film is similar to the structure of the above-mentioned selective reflection film, which can be realized by stacking multiple layers of films, which can be a structure formed by stacking organic films or inorganic films. For example, the P-polarized light reflective film may be a reflective polarizer (Reflecting polarizer mirror, RPM), that is, an RPM film.

For example, the surface of the reflection imaging part 20 facing the image source 10 is provided with the first phase retardation part 22 , the light emitted by the image generating part 200 includes the light of the S polarization state, and the first phase retardation part 22 is configured to enter the first phase The light in the S-polarized state of the retardation part 22 is converted into light in the non-S-polarized state, such as light in the P-polarized state, circularly polarized light, or elliptically polarized light.

For example, the image light emitted from the image source 10 includes light in the S polarization state, the first phase retardation part 22 may be a 1/2 wave plate, and a part of the light in the S polarization state incident on the first phase retardation part 22 may be reflected for imaging The part 20 is reflected to the observation area 30, and the other part is converted into the light of the P-polarized state after passing through the first phase retardation part 22. The light of the P-polarized state has a very low reflectivity on the outer inner surface of the reflection imaging part 20, and is basically transmitted out. , thereby eliminating ghosting.

For example, the image light emitted from the image source 10 includes light in the S polarization state, the first phase retardation part 22 may be a 1/4 wave plate, and a part of the light in the S polarization state incident on the first phase retardation part 22 may be reflected for imaging The reflection part 20 is reflected to the observation area 30, and the other part is converted into circularly polarized light after passing through the first phase retardation part 22. The circularly polarized light has a very low reflectivity on the outer inner surface of the reflection imaging part 20, which can improve or eliminate ghosting.

It should be noted that, for the purpose of illustration, there is a gap between the first phase retardation part 22 and the reflection imaging part 20, but in practical applications, the surface of the first phase retardation part 22 is close to the surface of the reflection imaging part 20; FIG. 15 The reflection imaging section 20 is also enlarged in the figure. For example, the thickness of the reflection imaging portion 20 is enlarged.

The head-up display provided in at least one embodiment of the present disclosure utilizes a beam splitting element, a direction changing element and a polarization converting element to convert almost all the unpolarized light emitted by the light source into light with a specific polarization state that can be utilized by the image generating unit, which can improve the The utilization rate of the light emitted by the light source, the light source can provide images with higher brightness under the same power conditions.

In the head-up display provided by at least one embodiment of the present disclosure, ghosting can be effectively eliminated by arranging a wedge-shaped film, a selective reflection film, a P-polarized light reflection film or a first phase retardation part in the reflection imaging part.

For example, the reflection imaging part, such as the windshield of a motor vehicle, has a relatively high reflectivity to the light in the S-polarized state (S-polarized light), and the light emitted by the image source of the head-up display generally includes the S-polarized light, for example, if the user (such as When the driver wears the sunglasses, the sunglasses filter the S-polarized light, so the driver cannot see the image of the head-up display when the driver wears the sunglasses. In at least one example of the embodiments of the present disclosure, a P-polarized light reflective film is provided on the side of the reflective imaging part in the head-up display facing the image source, and when the image light emitted by the image source includes light in the P-polarized state, the reflective imaging part may The image light in the P-polarized state is reflected to the observation area, so that the user wearing sunglasses whose eyes are located in the observation area can still see the image displayed by the image source, thereby improving the user experience.

For example, FIG. 16 is a schematic diagram of a partial structure of a head-up display provided according to at least one embodiment of the present disclosure. As shown in FIG. 16 , a second phase delay part 50 , such as a quarter wave plate, is provided between the image source 10 of the head-up display and the reflection imaging part 20 . The above-mentioned second phase delay part 50 is not closely arranged on the reflection imaging part 20 of the head-up display, and there is a certain distance between the second phase delay part 50 and the reflection imaging part, so that the light emitted by the image source 10 passes through the second phase delay part 50 After the phase delay part 50 is reflected by the reflection imaging part 20 , it does not pass through the second phase delay part 50 again, but directly exits to the observation area 30 . For example, the light emitted from the image source 10 includes the light of the S polarization state, and the second phase retardation part 50 is configured to convert the light of the S polarization state incident to the second phase retardation part 50 into the light of the circular polarization state (circularly polarized light ) or elliptically polarized light (elliptically polarized light), circularly polarized light or elliptically polarized light is reflected by the reflection imaging part 20 and then directed to the observation area 30, because the circularly polarized light or the elliptically polarized light includes a P polarization component, after being filtered by the sunglasses , the light of the P-polarized state enables a user wearing sunglasses whose eyes are located in the observation area 30 to still see the image displayed by the image source 10 , thereby improving the user experience.

For example, FIG. 17 is an exemplary block diagram of a transportation device provided in accordance with at least one embodiment of the present disclosure. As shown in FIG. 17 , the transportation device includes a heads-up display provided by at least one embodiment of the present disclosure. A front window of a traffic device (eg, a front windshield) is multiplexed as the reflective imaging portion 20 of the head-up display.

For example, the transportation equipment may be various suitable vehicles, for example, may include various types of land transportation equipment such as automobiles, or may be water transportation equipment such as boats. It can be transmitted to the front window.

It should be noted that, in the drawings for describing the embodiments of the present disclosure, the thicknesses of layers or regions are exaggerated or reduced for clarity, ie, the drawings are not drawn to actual scale.

Although the present disclosure has been described in detail above with general descriptions and specific implementations, some modifications or improvements can be made on the basis of the embodiments of the present disclosure, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present disclosure fall within the scope of the claimed protection of the present disclosure.

The following points need to be noted:

(1) In the drawings of the embodiments of the present disclosure, only the structures involved in the embodiments of the present disclosure are involved, and other structures may refer to general designs.

(2) Features in the same embodiment and different embodiments of the present disclosure may be combined with each other without conflict.

The above descriptions are only exemplary embodiments of the present disclosure, and are not intended to limit the protection scope of the present disclosure, which is determined by the appended claims.

Claims

An image source that includes:

a light source and an image generating portion, wherein the light emitted by the light source has a first polarization and a second polarization different from the first polarization, the image generating portion is configured to utilize the light having the first polarization The first polarized light or the second polarized light with the second polarization generates image light,

Wherein, the image source further includes a beam splitting element, a direction changing element and a polarization converting element,

The beam splitting element is configured to split the light emitted by the light source and incident on the beam splitting element into the first polarized light and the second polarized light, the first polarized light propagating to the image generating section, the second polarized light propagates to the direction changing element;

the direction changing element is configured to change the propagation direction of light incident on the direction changing element so as to be directed toward the image generating section;

The polarization conversion element is configured to convert the first polarized light and the second polarized light that cannot be utilized by the image generating unit into polarized light that can be used by the image generating unit before the polarized light reaches the image generating unit. polarized light used by the image generation unit.
The image source according to claim 1, wherein the first polarized light or the second polarized light used by the image generating section includes one of the first polarized light and the second polarized light being polarized by the The other of the polarized light converted by the conversion element and the first polarized light and the second polarized light not converted by the polarization conversion element.
The image source according to claim 1 or 2, wherein the first polarized light and the second polarized light both comprise linear polarized light, and the image generating part comprises a polarizing layer, the polarizing layer is located in the image The generation part is close to the side of the light source, and the polarization axis of the polarizing layer is parallel to the polarization direction of the first polarized light or the second polarized light,

The polarization conversion element is configured to convert the polarized light whose polarization direction is not parallel to the polarization axis among the first polarized light and the second polarized light into polarization before the polarized light reaches the image generating section Polarized light oriented parallel to the polarization axis.
4. The image source according to claim 3, wherein the polarization axis of the polarizing layer is parallel to the polarization direction of the second polarized light, and the beam splitting element is configured to transmit light with the first polarization. the transmittance is greater than the transmittance of light having the second polarization, and/or the reflectivity of the light having the second polarization is greater than the reflectivity of the light having the first polarization, the a direction changing element configured to reflect the second polarized light incident on the direction changing element to the image generating portion;

The polarization conversion element is located between the beam splitting element and the image generating section, and is configured to convert the first polarized light transmitted from the beam splitting element to the second polarized light by converting The obtained second polarized light is directed to the image generating unit.
4. The image source according to claim 3, wherein the polarization axis of the polarizing layer is parallel to the polarization direction of the first polarized light, and the beam splitting element is configured to transmit light with the first polarization. the transmittance is greater than the transmittance of light having the second polarization, and/or the reflectivity of the light having the second polarization is greater than the reflectivity of the light having the first polarization, the The beam splitting element is configured to transmit the light having the first polarization among the light source rays to the image generating unit, and reflect the light having the second polarization among the light source rays to the image generating unit direction changing element,

in,

The polarization conversion element is located between the direction change element and the image generating section and is configured to convert the second polarized light reflected from the direction change element to the first polarized light, and the resultant obtained by conversion is the first polarized light is directed towards the image generating section; or

The polarization conversion element is located between the direction changing element and the beam splitting element, and is configured to convert the second polarized light reflected from the beam splitting element toward the direction changing element into the first polarized light. a polarized light, and the direction changing element is configured to reflect the first polarized light obtained by the conversion to the image generating section.
6. The image source according to claim 5, wherein, in the case where the polarization conversion element is located between the direction changing element and the beam splitting element,

The polarization conversion element is configured to convert the second polarized light to the first polarized light by one conversion, or,

The polarization conversion element is configured to convert the second polarized light reflected from the beam splitting element toward the direction changing element into a third polarized light, the third polarized light being reflected by the direction changing element After passing through the polarization conversion element again, it is converted into the first polarized light, and the first polarized light obtained through the conversion is directed to the image generating unit.
2. An image source according to claim 1 or 2, wherein the direction changing element is located outside or in the optical path in which the polarization converting element is located,

in,

The polarized light that is not converted by the polarization conversion element in the first polarized light and the second polarized light is used by the image generation part after being processed by the direction changing element;

Or, after one of the first polarized light and the second polarized light is processed by a direction changing element, it is converted into polarized light that can be used by the image generating unit through the polarization converting element;

Or one of the first polarized light and the second polarized light is converted by the polarization conversion element into polarized light that can be used by the image generation unit, and then processed by the direction change element;

Or one of the first polarized light and the second polarized light is converted for the first time by the polarization conversion element, then processed by the direction change element, and then converted by the polarization conversion element for the second time. , which is converted into polarized light that can be used by the image generation unit.
7. The image source of any of claims 1-7, wherein the polarization conversion element is configured to convert polarized light incident thereon at least once, wherein,

The polarization conversion element is configured to convert the polarized light incident thereon once, and the polarization conversion element includes a half-wave plate;

The polarization conversion element is configured to convert polarized light incident thereon twice, and the polarization conversion element includes a quarter wave plate.
The image source according to any one of claims 1-8, wherein the polarization conversion element is attached to at least one of the beam splitting element and the direction changing element.
The image source according to any one of claims 1-9, wherein a transparent substrate is provided between the polarization conversion element and at least one element attached thereto, and the polarization conversion element and the element attached thereto are attached respectively The two surfaces of the transparent substrate which are opposite to each other are arranged in parallel.
The image source according to any one of claims 1-10, wherein the polarization directions of the first polarized light and the second polarized light are perpendicular, and one of the first polarized light and the second polarized light is One includes light in the S polarization state, and the other of the first polarization and the second polarization includes light in the P polarization state.
The image source according to any one of claims 1-11, wherein the direction changing element is located on the side of the beam splitting element facing the light source, and the beam splitting surface of the beam splitting element changes with the direction The reflective surfaces of the elements are parallel;

Alternatively, the beam splitting surface of the beam splitting element and the reflection surface of the direction changing element have a non-zero included angle.
The image source according to any one of claims 1-12, wherein the image source comprises a plurality of light conversion parts, each light conversion part comprises one of the beam splitting elements, one of the direction changing elements and one of the In the polarization conversion element, the number of the light sources is multiple, the multiple light sources and the multiple light conversion parts are arranged in a one-to-one correspondence, and the light emitted by each light source passes through a corresponding light conversion part and then goes to the image generation part.
The image source according to any one of claims 1-13, wherein the image generating section comprises a liquid crystal display panel.
The image source according to any one of claims 1-14, wherein the image source further comprises a reflective light guide element, a beam condensing element and a beam diffusing element,

At least a portion of the reflective light guide element is located between the light source and the beam splitting element, and is configured to reflect light emitted by the light source to collimate the light emitted from the reflective light guide element light;

the light beam condensing element is configured to condense the light rays directed to the image generating part;

The beam-spreading element is located between the beam-converging element and the image generating part, and/or between the beam-splitting element and the reflective light-guiding element, and is configured to pass through the beam-spreading element the beam is diffused.
A heads-up display comprising:

The image source of any of claims 1-15; and

The reflection imaging part is configured to reflect the light emitted from the image source to the observation area and transmit ambient light.
The head-up display according to claim 16, wherein the reflective imaging part is provided with a wedge-shaped film, and the wedge-shaped film is located in the interlayer of the reflective imaging part; or,

The surface of the reflection imaging part facing the image source is provided with a selective reflection film, and the selective reflection film is configured so that the reflectivity of the wavelength band where the image light emitted by the image generating part is located is greater than that except for the image light where the image light is located. The reflectivity of light in wavelengths outside the wavelength band; or,

The light emitted by the image generating portion toward the reflection imaging portion includes light in a P-polarized state, and a surface of the reflection imaging portion facing the image source is provided with a P-polarized light reflective film to reflect the image generating portion toward the image source. the light of the P-polarized state of the reflection imaging part; or,

The light emitted by the image generating portion toward the reflection imaging portion includes light in an S-polarized state, a surface of the reflection imaging portion facing the image source is provided with a first phase retardation portion, and the first phase retardation portion is configured In order to convert the light of the S-polarized state entering the first phase retardation part into the light of the non-S-polarized state.
The head-up display of claim 16, further comprising: a second phase retardation part located between the image source and the reflection imaging part,

Wherein, the light emitted by the image generating part includes light in an S-polarized state, and the second phase retardation part is configured to convert the light in the S-polarized state incident on the second phase retardation part to include circular polarization The converted light of the circular polarization state or the elliptical polarization state is reflected by the reflection imaging part and then directed to the observation area.
A transportation device comprising the heads-up display of any of claims 16-18.
The traffic device of claim 19, wherein the reflective imaging portion is a windshield of the traffic device.