CN219533528U

CN219533528U - Backlight assembly, image source device, head-up display, and traffic device

Info

Publication number: CN219533528U
Application number: CN202223190066.0U
Authority: CN
Inventors: 吴慧军
Original assignee: Futurus Technology Co Ltd
Current assignee: Futurus Technology Co Ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-08-15
Anticipated expiration: 2032-11-30

Abstract

The disclosure provides a backlight assembly, an image source device, a head-up display and traffic equipment, and relates to the technical field of head-up display. Wherein, the backlight assembly includes: the first light guide structure is used for homogenizing incident light; the light splitting element is arranged on the light emitting side of the first light guide structure and is used for splitting the light subjected to light homogenizing treatment, coupling out the first light obtained by light splitting to the second light guide structure and transmitting the second light obtained by light splitting to the direction adjusting element; the direction adjusting element is used for adjusting the transmission direction of the second light so as to enable the second light to be coupled out to the second light guide structure. With the above backlight assembly, the size of the backlight assembly can be further reduced while improving the uniformity of light.

Description

Backlight assembly, image source device, head-up display, and traffic device

Technical Field

The present disclosure relates to the field of optical display technologies, and in particular, to a backlight assembly, an image source device, a head-up display, and a traffic device.

Background

Head Up Display (HUD) projects image light onto a display device, and a user can directly see an imaging picture formed by the display device without lowering the head, so that better driving experience is brought.

Disclosure of Invention

One technical problem to be solved by the present disclosure is to improve light uniformity, and to provide a backlight assembly, an image source device, a head-up display, and a traffic device.

According to a first aspect of the present disclosure, there is provided a backlight assembly including: the first light guide structure is used for homogenizing incident light;

the light splitting element is arranged on the light emitting side of the first light guide structure and is used for splitting the light subjected to light homogenizing treatment, coupling out the first light obtained by light splitting to the second light guide structure and transmitting the second light obtained by light splitting to the direction adjusting element;

the direction adjusting element is used for adjusting the transmission direction of the second light so as to enable the second light to be coupled out to the second light guide structure.

In some embodiments, the light splitting element and the direction adjusting element are spaced along the length of the first light guiding structure; and/or the light splitting element and the direction adjusting element are relatively parallel arranged along the length direction of the first light guide structure; and/or the backlight assembly omits an adjustment element disposed at the light incident side of the first light guide structure.

In some embodiments, the thickness of the first light guiding structure is greater than or equal to h and less than 2h, where h is the length of the light source light emitting surface along the thickness direction of the first light guiding structure.

In some embodiments, the light splitting element comprises a polarization transflector, the first light comprises a first polarized light having a first polarization characteristic, the second light comprises a second polarized light having a second polarization characteristic, the first polarization characteristic being different from the second polarization characteristic, and the second light guiding structure comprises a polarization converting element and a light guiding element: the polarization conversion element is configured to perform polarization state conversion on one of the first polarized light and the second polarized light, so that polarization characteristics of the converted third polarized light are the same as polarization characteristics of unconverted polarized light; the light guiding element is configured to receive the unconverted polarized light and the third polarized light, and couple out the unconverted polarized light and the third polarized light.

In some embodiments, the first light guiding structure is a cavity structure, and includes a first light guiding plate and a second light guiding plate, so that incident light is reflected between the first light guiding plate and the second light guiding plate for multiple times to achieve uniform light; or the first light guide structure is a solid structure and comprises a first light guide surface and a second light guide surface, and the first light guide structure is used for enabling incident light to be reflected between the first light guide surface and the second light guide surface for multiple times so as to realize uniform light.

In some embodiments, the first light guide plate and the second light guide plate are disposed relatively parallel, or the first light guide surface and the second light guide surface are disposed relatively parallel; or the first light guide plate and the second light guide plate are arranged in a relatively inclined manner, and the included angle between the first light guide plate and the second light guide part is smaller than or equal to the divergence angle of the light from the light source, or the first light guide surface and the second light guide surface are arranged in a relatively inclined manner, and the included angle between the first light guide surface and the second light guide surface is smaller than or equal to the divergence angle of the incident light.

In some embodiments, at least one of the first light guide plate and the second light guide plate is provided with a reflective film.

In some embodiments, the direction adjusting element is a reflecting element, and the reflecting element is spaced from the light splitting element; or the direction adjusting element is a reflecting surface of a solid light-transmitting structure, the light splitting element is attached to one surface of the solid light-transmitting structure, and the reflecting surface is one surface, far away from the light splitting element, of the solid light-transmitting structure.

In some embodiments, the light guiding element comprises: the light guide body is used for transmitting the light entering the light guide element; the coupling-out element group is arranged in the light guide body and is positioned in the projection area of the display panel, and the coupling-out element group is used for coupling out part of received light to the display panel and continuously transmitting the other part of the received light in the light guide body.

In some embodiments, the light guiding element further includes a coupling-in element group disposed in the light guiding body and located outside the projection area of the display panel, for reflecting the received light to the coupling-out element group; and/or the light guiding element further comprises a reflecting element group, the reflecting element group comprises at least one reflecting element, the reflecting element group is positioned in a projection area of the display panel and positioned at the tail end of the coupling-out element group along the propagation direction of light in the light guiding body, and the reflectivity of the reflecting element is 1.

In some embodiments, the second light guiding structure further comprises: and the dimming element is arranged between the first light guide structure and the light guide element and is used for toning the first light or the second light.

In some embodiments, the dimming element comprises at least one of a wavelength conversion element and a color filter.

In some embodiments, the backlight assembly further includes a light source disposed at the light incident side of the first light guide structure.

According to a second aspect of the present disclosure, there is provided a backlight assembly including: the first light guide structure comprises a light homogenizing part and a coupling-out part, wherein the light homogenizing part is used for homogenizing light from a light source; the light splitting element is arranged on the light emitting side of the light homogenizing part so as to omit an adjusting element arranged on the light entering side of the first light guiding structure, the light splitting element is used for splitting the light subjected to light homogenizing treatment to obtain first light and second light, the first light is coupled to the second light guiding structure by the light splitting element, and the second light is transmitted to the second light guiding structure through the coupling-out part.

According to a third aspect of the present disclosure, there is provided a backlight assembly including: the first light guide structure is used for homogenizing the incident light and transmitting the homogenized light to the second light guide structure; a second light guiding structure comprising: the light guide body is used for transmitting the light entering the second light guide structure; the coupling-out element group is arranged in the light guide body and is positioned in the projection area of the display panel, and the coupling-out element group is used for coupling out part of the received light to the display panel and continuously transmitting the other part of the received light in the light guide body.

According to a fourth aspect of the present disclosure, there is provided an image source apparatus including: a light source; a backlight assembly as described above; and a display panel for receiving light emitted from the backlight assembly and forming image light according to the light emitted from the backlight assembly.

In some embodiments, the image source device further comprises at least one of the following elements: a direction control element disposed between the backlight assembly and the display panel, for controlling a direction of light emitted from the backlight assembly so that the light emitted from the backlight assembly can be incident toward the display panel; and the light diffusion element is arranged between the backlight assembly and the display panel and used for diffusing light coupled out of the backlight assembly.

According to a fifth aspect of the present disclosure, there is provided a head-up display comprising: an image source device as described above for emitting image light; and the display device is used for generating an imaging picture according to the image light.

According to a sixth aspect of the present disclosure, there is provided a traffic device comprising: a head-up display as hereinbefore described.

In some embodiments, the display device is a windshield of the traffic device or a separately provided imaging panel.

Other features of the present disclosure and its advantages will become apparent from the following detailed description of exemplary embodiments of the disclosure, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The disclosure may be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic structural view of a backlight assembly according to some embodiments of the present disclosure;

fig. 2 is a schematic structural view of a backlight assembly according to other embodiments of the present disclosure;

fig. 3 is a schematic structural view of a backlight assembly according to still other embodiments of the present disclosure;

FIG. 4 is a schematic diagram of an arrangement of coupling-out elements in accordance with some embodiments of the present disclosure;

FIG. 5 is a schematic diagram of an arrangement of coupling-out elements according to further embodiments of the present disclosure;

FIG. 6 is a schematic diagram of a structure of a derivation element in accordance with some embodiments of the present disclosure;

fig. 7 is a schematic structural diagram of an image source device according to some embodiments of the present disclosure;

fig. 8 is a schematic structural view of an image source device according to other embodiments of the present disclosure;

fig. 9 is a schematic structural view of an image source device according to further embodiments of the present disclosure;

FIG. 10 is a schematic diagram of a structure of a light source according to some embodiments of the present disclosure;

fig. 11 is a schematic structural diagram of a head-up display according to some embodiments of the present disclosure.

Fig. 12 is a schematic structural view of a traffic device according to some embodiments of the present disclosure.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative, and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments should be construed as exemplary only and not limiting unless otherwise specifically stated.

The terms "first," "second," and the like, as used in this disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises" and the like means that elements preceding the word encompass the elements recited after the word, and not exclude the possibility of also encompassing other elements. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

In this disclosure, when a particular element is described as being located between a first element and a second element, there may or may not be intervening elements between the particular element and the first element or the second element. When it is described that a specific component is connected to other components, the specific component may be directly connected to the other components without intervening components, or may be directly connected to the other components without intervening components.

All terms (including technical or scientific terms) used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs, unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

A backlight assembly is used in a head up display device. The inventors of the present utility model found in the study that: first, since the light emitted by the light source tends to be uneven, for example, the light emitted by the (LED) tends to be bright in the center and dark in the periphery, and in the related art, the uniformity of the light emitted by the light source after being coupled out by the backlight assembly is poor; the second, the product size of the backlight assembly in the related art is bigger, occupation space is bigger for the whole product size of new line display device is bigger, has restricted new line display device's application scope, has influenced user experience.

In view of this, the present disclosure proposes a backlight assembly, an image source device, a head-up display, and a traffic device to reduce a product size while improving uniformity of light.

Fig. 1 is a schematic structural view of a backlight assembly according to some embodiments of the present disclosure. As shown in fig. 1, a backlight assembly of an embodiment of the present disclosure includes: the first light guiding structure 110, the light splitting element 120, and the direction adjusting element 130.

The first light guiding structure 110 is used for homogenizing the incident light. For example, the first light guiding structure receives light emitted by the light source and performs light homogenizing treatment on the received light.

The light splitting element 120 is disposed on the light emitting side of the first light guiding structure 110, and is configured to split the light after the light homogenizing process, couple out the first light obtained by the light splitting to the second light guiding structure, and transmit the second light obtained by the light splitting to the direction adjusting element 130. For example, the spectroscopic element 120 is a polarization transflective element. For example, the spectroscopic element 120 is an element that reflects light of parallel polarization and transmits light of perpendicular polarization. Alternatively, the spectroscopic element 120 is an element that reflects light of perpendicular polarization and transmits light of parallel polarization.

The direction adjusting element 130 is configured to adjust a transmission direction of the second light, so that the second light is coupled out to the second light guiding structure. For example, the direction adjustment element 130 is a reflective member provided alone, or a reflective surface included in a solid structure provided alone.

In the embodiment of the disclosure, the light emitted by the light source can be converted into linearly polarized light under the condition of minimizing light loss by arranging the light splitting element and the direction adjusting element, so that the linearly polarized light is utilized by the display panel, the utilization rate of the light is improved, and the brightness of the light emitting brightness of the backlight assembly is improved. In addition, by providing the light splitting element 120 and the direction adjusting element 130 on the light emitting side of the first light guiding structure, compared with the light splitting element provided on the light incident side of the first light guiding structure in the related art, the adjustment of the light splitting and the light propagation direction can be achieved without providing additional elements, so that the size of the backlight assembly, particularly the thickness of the backlight assembly, can be reduced, the volume of the backlight assembly is smaller, and the application range of the backlight assembly can be improved. Moreover, compared with the related art, since the embodiment of the present disclosure omits the adjustment element provided at the light incident side of the first light guide structure, the adjustment element is used to change the propagation direction of the light, so that the light can continue to propagate within the first light guide structure, and the cost of the backlight assembly can be further reduced.

In some embodiments, the light splitting element 120 and the direction adjusting element 130 are disposed at intervals along the length direction of the first light guiding structure 110. For example, the light splitting elements and the direction adjusting elements are disposed in parallel and at intervals along the length direction of the first light guiding structure 110. This can realize light splitting, and make the outgoing direction of the first light and the outgoing direction of the second light after light splitting the same.

In some embodiments, the direction adjustment element 130 is a reflective element that is provided separately and spaced apart from the light splitting element.

In some embodiments, the direction adjusting element 130 is a reflective surface of a solid structure, and the light splitting element 120 is attached to one surface of the solid structure, and the reflective surface is a surface of the solid structure away from the light splitting element 120. For example, the spectroscopic element is a polarization transmission film provided on the surface of the solid structure, or the spectroscopic element is a polarization transmission reflection element which is attached to one surface of the solid structure and is provided separately.

The second light guide structure is used for converting received light into surface light source and coupling out.

In some embodiments, the first light received by the second light guiding structure comprises first polarized light having a first polarization characteristic, and the second light received by the second light guiding structure comprises second polarized light having a second polarization characteristic, the first polarization characteristic being different from the second polarization characteristic. And the second light guide structure is used for carrying out polarization state conversion on one of the first polarized light and the second polarized light so that the polarization characteristic of the converted third polarized light is the same as that of the unconverted polarized light, and coupling out the third polarized light and the unconverted polarized light. In the embodiment of the disclosure, the second light guide structure is provided, and the second light guide structure converts the incident light into two beams of light with the same polarization characteristic, so that the two beams of polarized light can be utilized by the display panel, thereby improving the light utilization rate in the backlight assembly and further being beneficial to improving the light-emitting brightness of the backlight assembly.

The first light guide structure and the second light guide structure are described in detail below.

The first light guide structure 110 includes a first light guide portion 111 and a second light guide portion 112. By causing light to be reflected between the first light guide portion 111 and the second light guide portion 112 a plurality of times, it is helpful to improve uniformity of light output from the backlight assembly.

In some embodiments, the first light guiding structure 110 is a solid transparent structure, and the first light guiding portion 111 and the second light guiding portion 112 are two opposite surfaces of the solid transparent structure, which are respectively denoted as a first light guiding surface and a second light guiding surface. Light from the light source is reflected between the first light guide plate and the second light guide plate for multiple times so as to realize uniform light. The first light guide structure is made to be a solid transparent structure, and light rays are reflected between the first light guide surface and the second light guide surface for multiple times, so that the light emitting uniformity can be improved, the light transmission loss can be reduced, and the light utilization rate can be improved.

Alternatively, in some embodiments, the first light guiding structure 110 is a cavity structure, and the first light guiding portion 111 and the second light guiding portion 112 are two light guiding plates disposed opposite to each other, which are respectively denoted as a first light guiding plate and a second light guiding plate, and are configured to make incident light reflect multiple times between the first light guiding plate and the second light guiding plate, so as to achieve uniform light. The first light guide structure is made to be a cavity structure, and light rays are reflected between the first light guide plate and the second light guide plate for multiple times, so that the light emitting uniformity can be improved, the weight of the backlight assembly is reduced, and the product weight is reduced.

After entering the first light guiding structure 110, the light is reflected between the first light guiding portion 111 and the second light guiding portion 112 for multiple times in a total reflection or non-total reflection manner, so that the light can be fully mixed before being coupled out from the light emitting side of the first light guiding structure, and the uniformity of the light is improved. For example, by controlling the emission angle of the light emitted from the light source and the shape of the first light guide structure, the incident angle of the light incident on the first light guide portion and the second light guide portion is made to be greater than or equal to the critical angle of total reflection, so that the light is reflected multiple times between the first light guide portion and the second light guide portion in a total reflection manner.

The light emitted by the light source typically has a certain divergence angle, such as a divergence angle of + -10 degrees. After the light enters the first light guiding structure 110, the light is reflected between the first light guiding portion 111 and the second light guiding portion 112 for a plurality of times. Since the light beam has a divergence angle, the incident angles of light incident on the first light guide portion or the second light guide portion at different distances from the center of the light beam may be different, and thus reflected to different positions, the light rays can be sufficiently mixed by multiple reflections, so that the uniformity of the light (particularly, the brightness uniformity) is increased. Further, by causing light to undergo total reflection between the first light guide portion and the second light guide portion a plurality of times, not only can uniformity of light be improved, but also transmission loss of light in the first light guide structure can be reduced, and light utilization efficiency can be improved.

In some embodiments, the first light guiding portion 111 and the second light guiding portion 112 are disposed obliquely with respect to each other, and an included angle between the two is smaller than a divergence angle of light incident to the first light guiding structure. Through the above setting, on the one hand, can reduce the distance of at least some region between first light guide part and the second light guide part, and then help increasing the reflection number of times of light in first light guide structure, improve first light guide structure's even light effect, on the other hand, help promoting the even light effect of wide-angle light.

In some embodiments, at least one of the first light guide 111 and the second light guide 112 is provided with a reflective film. For example, a reflective film is provided on the second light guide 112. For example, a metal film such as an aluminum film may be provided on the second light guide portion by means of a film or a plating film. By arranging the reflecting film on at least one of the first light guide part and the second light guide part, the loss caused by refraction when light rays are transmitted inside the first light guide structure can be reduced, the light utilization rate is improved, and the light emitting brightness of the backlight assembly is improved.

In some embodiments, the second light guiding structure includes a light guiding element 140 and a polarization conversion element 150. And a polarization conversion element 150 for performing polarization conversion on the first polarized light or the second polarized light so that the polarization state of the converted third polarized light is the same as that of the unconverted polarized light, thereby obtaining two polarized light beams with the same polarization state. As shown in fig. 1, the polarization conversion element 150 is configured to convert the polarization state of the second polarized light, so that the polarization state of the converted third polarized light is the same as that of the first polarized light. For example, the polarization conversion element 140 is a half wave plate.

The light guiding element 140 is configured to receive and couple out two polarized lights with the same polarization state. For example, as shown in fig. 1, the light guiding element 140 is configured to receive light of the first polarization and light of the third polarization, and couple out the light of the first polarization and the light of the third polarization.

In some embodiments, the light guiding element 140 includes a light guiding body 141 and a set of coupling-out elements.

The light guiding body 141 is used for transmitting the light entering the light guiding element. In some embodiments, the light guiding body 141 is a cavity structure. Thus, the overall weight can be reduced, and the weight can be reduced.

In some embodiments, the light guiding body 141 is a hollow cavity structure and is a solid transparent structure. Therefore, the structure is more compact, and the loss in the light transmission process is smaller, thereby being beneficial to improving the energy efficiency.

The coupling-out element group is arranged in the light guide body and is positioned in the projection area of the display panel, and the coupling-out element group is used for coupling out part of the received light to the display panel and continuously transmitting the other part of the received light in the light guide body.

In some embodiments, the coupling-out element group includes a plurality of coupling-out elements 142 disposed in the light guiding body, and the coupling-out elements are used to couple out a part of the received light to the display panel and to continue transmitting another part of the received light in the light guiding body. By arranging the plurality of coupling-out elements on the light guide body, light from the first light guide structure can be spatially expanded to convert incident light into a surface light source, so that the light emitting uniformity of the backlight assembly is further improved.

In some embodiments, the plurality of coupling-out elements included in the coupling-out element group are disposed in parallel and spaced apart from each other in the light guiding body 141.

In some embodiments, the plurality of out-coupling elements are arranged in order of the coupling-out ratio in a direction along the light transmission in the light guiding body. For example, as shown in fig. 1, light is transmitted from right to left in the light guide body, and the coupling-out ratio of the plurality of coupling-out elements arranged in order from right to left increases. By gradually changing the coupling rate of the plurality of coupling-out elements, the uniformity of the backlight assembly can be further improved.

In some embodiments, the out-coupling element is a transflective element or an out-coupling grating. For example, the light guiding body is of a cavity structure, and the coupling-out element is a transflective element separately arranged inside the light guiding body. For example, the light guiding body is a solid structure, and the coupling-out element is a transflective film disposed on an inner surface of the light guiding body.

In some embodiments, the light guiding element further includes a coupling-in element set disposed in the light guiding body and located outside the projection area of the display panel, for reflecting all the received light to the coupling-out element set. By arranging the coupling-in element group and matching the coupling-out element group with the coupling-in element group, on one hand, the light can be coupled out to the area where the display panel is located as much as possible, so that the light can be utilized by the display panel, the light utilization rate is improved, and on the other hand, the light can be further mixed before the light is coupled out to the display panel, so that the light emitting uniformity of the backlight assembly is improved.

In some embodiments, the light guiding element further includes a reflective element group, the reflective element group includes at least one reflective element, and the reflective element group is disposed in the projection area of the display panel and is located at an end of the coupling-out element group along a propagation direction of light in the light guiding body, and a reflectivity of the reflective element is 1. The light guide element is also provided with the reflecting element group, and the reflecting element group is matched with the coupling-out element group, so that light can be coupled out to the area where the display panel is positioned as much as possible, the light loss is reduced, and the light utilization rate is improved.

In some embodiments, the projection area of the light coupled out by the coupling-out element group and the reflection element group corresponds to the display area of the display panel. For example, the total projected area of the light coupled out by the coupling-out element group and the reflecting element group is the same size as the display area of the display panel. The projection area of the light coupled out by the coupling-out element group and the reflecting element group corresponds to the display area of the display panel, so that the light can be coupled out to the area where the display panel is positioned as much as possible, the light can be utilized by the display panel, and the light utilization rate is improved.

In some embodiments, considering that the light-splitting element and the polarization-converting element are often made of a polymer material, the polymer material has a characteristic that when the incident angle of the light is relatively large (for example, 40 ° or more), the relationship between the transmittance and the wavelength of the light changes compared with the case of the light perpendicularly or almost perpendicularly incident, which is specifically expressed as follows: at high angles of incidence, its transmission for short waves (e.g. blue light) decreases, while its transmission for long waves (e.g. red light) increases. Therefore, the wave band of the light transmitted by the light-splitting element moves towards the long wave direction, the wave band of the light reflected by the light-splitting element moves towards the short wave direction, the light transmitted by the light-splitting element is yellow, the light reflected by the light-splitting element is blue, and the color cast phenomenon is generated.

In view of this, in these embodiments, in order to solve the color shift problem, the dimming element 160 is provided in the backlight assembly. The light adjusting element 160 is configured to perform color adjustment on one of the two paths of linearly polarized light, so that the colors of the two paths of linearly polarized light are consistent. For example, as shown in fig. 1, the light adjusting element 160 is disposed in the optical path of the linearly polarized light transmitted by the spectroscopic element 130.

In some embodiments, the dimming element 160 includes at least one of a wavelength conversion element and a color filter.

In the embodiment of the disclosure, through the backlight assembly, the size of the backlight assembly can be further reduced while the light emitting uniformity and the light emitting brightness of the backlight assembly are improved, and the application range of the backlight assembly is improved.

Fig. 2 is a schematic structural view of a backlight assembly according to other embodiments of the present disclosure. As shown in fig. 2, the backlight assembly of the embodiment of the present disclosure includes a first light guide structure 110, a light splitting element 120, a direction adjusting element 130, and a second light guide structure.

The backlight assembly of the embodiment of the present disclosure is mainly different from the backlight assembly shown in fig. 1 in that the first light guide portion 111 and the second light guide portion 112 in the first light guide structure 110 are disposed relatively in parallel.

In some embodiments, the first light guiding structure 110 further satisfies: the thickness of the first light guide structure is greater than or equal to h and less than 2h, wherein h is the length of the light emitting surface of the light source in the thickness direction of the first light guide structure.

For example, when the first light guide portion 111 and the second light guide portion 112 are disposed in parallel, the thickness of the first light guide structure is a fixed value, and the fixed value is equal to or greater than h and less than 2h.

For example, when the first light guide portion 111 and the second light guide portion 112 are disposed obliquely with respect to each other, the thickness of the first light guide structure on the light incident side is equal to or greater than h and less than 2h.

In the embodiment of the disclosure, the thickness of the first light guiding structure is greater than or equal to the length of the light emitting surface of the light source and less than 2 times the length of the light emitting surface of the light source, so that the light emitted by the light source is coupled into the first light guiding structure as much as possible, thereby improving the light utilization rate, and simultaneously, reducing the thickness of the backlight assembly as much as possible and improving the overall effect of the backlight assembly.

Fig. 3 is a schematic structural view of a backlight assembly according to still other embodiments of the present disclosure. As shown in fig. 3, the backlight assembly of the embodiment of the present disclosure includes a first light guide structure 110, a light splitting element 120, a direction adjusting element 130, and a second light guide structure. The second light guiding structure includes a light guiding element 140, a polarization conversion element 150, and a dimming element 160.

The backlight assembly of the embodiment of the present disclosure is mainly different from the backlight assembly shown in fig. 1 in the arrangement position of the polarization conversion element 150. And a polarization conversion element 150 disposed in the optical path of the second polarized light, for performing polarization state conversion on the second polarized light transmitted by the light splitting element so that the polarization characteristics of the converted third polarized light are the same as those of the first polarized light. Accordingly, the light guiding element 140 is configured to receive the first polarized light and the third polarized light, and couple out the first polarized light and the third polarized light.

And a light adjusting element 160 disposed in the optical path of the second polarized light transmitted by the light splitting element.

In other embodiments of the present disclosure, the polarization conversion element 150 and the dimming element 160 may also be disposed in the optical path of the first polarized light reflected by the light splitting element.

Fig. 4 is a schematic partial structure of a light guiding element according to some embodiments of the present disclosure. In fig. 4, the arrangement of the outcoupling element group and the reflecting element group is described taking an example that the outcoupling element group in the light guiding element includes 4 outcoupling elements (outcoupling elements b to e) and the reflecting element group includes 1 reflecting element (reflecting element a).

In some embodiments, the reflective element a, the coupling-out elements b to e are arranged in parallel and spaced apart from each other in the light guiding body.

In some embodiments, the light rays are transmitted inside the light guide body without total reflection from the upper and lower surfaces of the light guide body. In practice, this can be achieved by adjusting the incident angle of the light and the setting angle of the coupling-out element (i.e. the angle β shown in fig. 4). For example, the light from the first light guiding structure is made to be incident vertically or almost vertically, and the setting angle of the coupling-out element and the reflecting element is made to be 45 °.

In some embodiments, the coupling rate of the coupling-out elements b to e is greater than 0 and less than 1, and the coupling rate of the reflective element a is 1. By the arrangement, the light loss in the backlight assembly can be reduced, and the brightness of the light can be improved.

Fig. 5 is a schematic partial structure of a light guide element according to other embodiments of the present disclosure. In fig. 5, the arrangement of the outcoupling element group and the reflecting element group is described taking the example that the outcoupling element group in the light guiding element includes 3 outcoupling elements (outcoupling elements b to d) and the reflecting element group includes one reflecting element (reflecting element a).

Wherein the reflective element a, the coupling-out elements b to d are arranged in parallel and spaced apart from each other in the light guiding body.

In some embodiments, as shown in fig. 5, light is totally reflected by the upper and lower surfaces of the light guiding body when transmitted inside the light guiding body. In practice, this can be achieved by adjusting the incident angle of the light and the setting angle of the coupling-out element (i.e. the included angle β shown in fig. 5). For example, the light from the first light guiding structure is made to enter vertically or almost vertically, and the setting angle of the reflecting element and the coupling-out element is made to be 25-35 degrees.

Fig. 6 is a schematic structural view of a light guiding element according to some embodiments of the present disclosure. As shown in fig. 6, the light guiding element includes a coupling-in element group in addition to a light guiding body, a coupling-out element group and a reflecting element group disposed inside the light guiding body. Wherein the set of coupling elements comprises at least one coupling element 143.

The projection area of the light coupled out by the coupling-out element group and the reflection element group corresponds to the display area of the display panel 300. The set of coupling-out elements includes 3 coupling-out elements, namely, coupling-out element 1421, coupling-out element 1422, and coupling-out element 1423 in this order, and the coupling-out rates of the three coupling-out elements satisfy: the coupling-out element 1421< the coupling-out element 1422< the coupling-out element 1423. The reflection element group includes a reflection element 144, and the reflectance of the reflection element 144 is 1.

The coupling-in element 143 is disposed in the light guiding body, and is used for adjusting the transmission direction of the light entering the light guiding body so as to transmit the adjusted light to the coupling-out element group. In some embodiments, as shown in fig. 6, the coupling-in element 143 is a reflective element. In other embodiments, the coupling-in element may also be a transmissive element.

According to some embodiments of the present disclosure, there is also provided a backlight assembly. The backlight assembly includes a first light guide structure, a light splitting assembly, and a second light guide structure.

The first light guide structure comprises a light homogenizing part and a coupling-out part, wherein the light homogenizing part is used for homogenizing light from the light source.

The light splitting element is arranged on the light emitting side of the light homogenizing part so as to omit an adjusting element arranged on the light entering side of the first light guiding structure, and is used for splitting the light subjected to light homogenizing treatment to obtain first light and second light, wherein the first light is coupled to the second light guiding structure by the light splitting element, and the second light is transmitted to the second light guiding structure through the coupling-out part.

The second light guide structure is used for converting the received first light and the second light into surface light sources and coupling out the converted light to the display panel.

In the embodiment of the disclosure, by arranging the light splitting element on the light emitting side of the first light guiding structure, compared with the arrangement of the light splitting element on the light entering side of the first light guiding structure in the related art, the size of the backlight assembly can be reduced, especially the thickness of the backlight assembly is reduced, so that the volume of the backlight assembly is smaller, and the application range of the backlight assembly is improved. Further, by adjusting the propagation direction of the second light based on the coupling-out portion of the first light guide structure, compared to the related art, a separately provided adjustment element can be omitted, and the size of the backlight assembly can be further reduced, and the cost of the backlight assembly can be reduced.

According to some embodiments of the present disclosure, there is also provided a backlight assembly. The backlight assembly includes a first light guide structure and a second light guide structure.

The first light guide structure is used for homogenizing light from the light source and transmitting the homogenized light to the second light guide structure.

The second light guide structure comprises a light guide body and a coupling-out element group. The light guide body is used for transmitting light entering the second light guide structure. The coupling-out element group is arranged in the light guide body and is positioned in the projection area of the display panel, and the coupling-out element group is used for coupling out part of the received light to the display panel and continuously transmitting the other part of the received light in the light guide body. According to the embodiment of the disclosure, through the backlight assembly, the emergent light can be irradiated on the display area of the display panel as much as possible while the emergent light uniformity is improved, so that the emergent light utilization rate of the backlight assembly can be improved, the display area of the display panel can be illuminated, and the user watching experience can be improved.

Fig. 7 is a schematic structural diagram of an image source device according to some embodiments of the present disclosure. As shown in fig. 7, an image source device of an embodiment of the present disclosure includes: backlight assembly 100, display panel 300.

In some embodiments, the backlight assembly 100 includes the light source 200 in addition to the first and second light guide structures.

In some embodiments, the light source 200 includes a light source portion and a collimating element. Wherein the light source part is used for emitting light; the collimating element is used for collimating the light emitted by the light source part. By collimating the light emitted from the light source section, the light utilization efficiency is improved.

The first light guide structure and the second light guide structure are used for homogenizing light emitted by the light source and coupling out the homogenized light. Illustratively, the first light guide structure and the second light guide structure in the backlight assembly 100 may employ any of the structures of the foregoing embodiments.

The display panel 300 is configured to receive light emitted from the backlight assembly 100 and form image light according to the light emitted from the backlight assembly.

In the embodiments of the present disclosure, by the above-described design of the backlight assembly, light can be uniformly irradiated onto the display panel, thereby contributing to an improvement in the imaging effect of the display panel. At the same time, the light utilization efficiency is improved, thereby contributing to the improvement of the brightness of the display panel.

Fig. 8 is a schematic structural diagram of an image source device according to other embodiments of the present disclosure. As shown in fig. 8, the image source device according to the embodiment of the present disclosure is further improved over the embodiment shown in fig. 7, and mainly includes: a first direction control element 410, a second direction control element 420, a light expansion element 430, and an antiglare film 440 are added.

The first direction control element 410 and the second direction control element 420 are disposed between the backlight assembly 100 and the display panel 300, and are used for controlling the direction of light emitted from the backlight assembly so that the light emitted from the backlight assembly can be incident toward the display panel. For example, the first and second directional control elements 410 and 420 are lenses, fresnel lenses, or the like.

The light diffusing element 430 is disposed between the backlight assembly and the display panel, and is used for diffusing light coupled out of the backlight assembly. For example, light diffusing element 430 includes a light homogenizing sheet. By diffusing the light, the uniformity of the light can be further improved.

The anti-glare film 440 can perform an anti-glare function, contributing to an improved viewing experience for the user.

Fig. 9 is a schematic structural diagram of an image source device according to still other embodiments of the present disclosure. As shown in fig. 9, the image source device according to the embodiment of the present disclosure is mainly different from the image source device shown in fig. 8 in that a third direction control element 450 is further added.

The third directional control element 450 is disposed between the first directional control element 410 and the second directional control element 420. The first and second direction control elements 410 and 420 and the third direction control element 450 are used to control the direction of the light emitted from the backlight assembly so that the light emitted from the backlight assembly can be incident toward the display panel. For example, the first direction control element 410, the second direction control element 420, or the third direction control element 450 is a lens, or a fresnel lens, or the like.

Fig. 10 is a schematic structural view of a light source according to some embodiments of the present disclosure. As shown in fig. 10, the light source includes a light source portion 210 and a collimator element 220.

The light source 210 includes a lamp panel and a lamp bead provided on the lamp panel. Wherein the beads may emit light comprising a P-polarized light component and an S-polarized light component.

The collimating element 220, which may be a collimating lamp cup, is used to collimate the light emitted by the light source. Illustratively, the collimating cup comprises at least one of a total reflecting cup and a parabolic reflecting cup.

Fig. 11 is a schematic structural diagram of a head-up display according to some embodiments of the present disclosure. As shown in fig. 11, the head-up display includes an image source device 11 and a display device 12.

The image source device 11 is used for emitting imaging light.

And a display device 12 for reflecting the imaging light to obtain an imaging picture. The display device 12 is illustratively a windshield or a separately provided imaging plate.

According to the embodiment of the disclosure, through the head-up display, a user can see an imaging picture with uniform brightness, and user experience is improved.

Fig. 12 is a schematic structural view of a traffic device according to some embodiments of the present disclosure. As shown in fig. 12, the traffic device 1 includes a head-up display 10.

The traffic device 1 includes, but is not limited to, land vehicles such as vehicles, air vehicles such as aircraft, or water or underwater vehicles.

The head-up display 10 includes an image source device and a display device.

In some embodiments, the display device is a windshield of a traffic device or a separately provided imaging panel.

Up to this point, the backlight assembly, the image source device, the head up display, and the traffic device according to the present disclosure have been described in detail. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above description.

Claims

1. A backlight assembly, comprising:

the first light guide structure is used for homogenizing incident light, the thickness of the first light guide structure is more than or equal to h and less than 2h, and h is the length of the light source light-emitting surface in the thickness direction along the first light guide structure;

2. The backlight assembly of claim 1, wherein:

the light splitting element and the direction adjusting element are arranged at intervals along the length direction of the first light guide structure; and/or

The light splitting element and the direction adjusting element are relatively parallel to each other along the length direction of the first light guide structure; and/or

The backlight assembly omits an adjustment element disposed at an incident side of the first light guide structure.

3. The backlight assembly of claim 1, wherein:

the light splitting element includes a polarization transreflective element, the first light includes a first polarized light having a first polarization characteristic, the second light includes a second polarized light having a second polarization characteristic, the first polarization characteristic is different from the second polarization characteristic, and the second light guiding structure includes a polarization conversion element and a light guiding element:

the polarization conversion element is configured to perform polarization state conversion on one of the first polarized light and the second polarized light, so that polarization characteristics of the converted third polarized light are the same as polarization characteristics of unconverted polarized light;

The light guiding element is configured to receive the unconverted polarized light and the third polarized light, and couple out the unconverted polarized light and the third polarized light.

4. The backlight assembly of claim 1, wherein:

the first light guide structure is a cavity structure and comprises a first light guide plate and a second light guide plate, and is used for enabling incident light to be reflected between the first light guide plate and the second light guide plate for multiple times so as to realize uniform light; or alternatively

The first light guide structure is a solid structure and comprises a first light guide surface and a second light guide surface, and the first light guide structure is used for enabling incident light to be reflected between the first light guide surface and the second light guide surface for multiple times so as to realize light evening.

5. The backlight assembly of claim 4, wherein:

the first light guide plate and the second light guide plate are arranged in parallel relatively, or the first light guide surface and the second light guide surface are arranged in parallel relatively; or alternatively

The first light guide plate and the second light guide plate are arranged in a relatively inclined manner, the included angle between the first light guide plate and the second light guide plate is smaller than or equal to the divergence angle of the incident light, or the first light guide surface and the second light guide surface are arranged in a relatively inclined manner, and the included angle between the first light guide surface and the second light guide surface is smaller than or equal to the divergence angle of the incident light.

6. The backlight assembly of claim 4, wherein at least one of the first and second light guide plates is provided with a reflective film.

7. The backlight assembly of claim 1, wherein:

the direction adjusting element is a reflecting element, and the reflecting element and the light splitting element are arranged at intervals; or alternatively

The direction adjusting element is a reflecting surface of a solid light-transmitting structure, the light splitting element is attached to one surface of the solid light-transmitting structure, and the reflecting surface is one surface, far away from the light splitting element, of the solid light-transmitting structure.

8. A backlight assembly according to claim 3, wherein the light guiding element comprises:

the light guide body is used for transmitting the light entering the light guide element;

the coupling-out element group is arranged in the light guide body and is positioned in the projection area of the display panel, and the coupling-out element group is used for coupling out part of received light to the display panel and continuously transmitting the other part of the received light in the light guide body.

9. The backlight assembly of claim 8, wherein:

the light guide element further comprises a coupling-in element group, wherein the coupling-in element group is arranged in the light guide body and is positioned outside the projection area of the display panel, and is used for reflecting all received light to the coupling-out element group; and/or

The light guide element further comprises a reflecting element group, the reflecting element group comprises at least one reflecting element, the reflecting element group is located in a projection area of the display panel and located at the tail end of the coupling-out element group in the propagation direction of light in the light guide body, and the reflectivity of the reflecting element is 1.

10. The backlight assembly of any one of claims 3 to 9, wherein the second light guiding structure further comprises:

and the dimming element is arranged between the first light guide structure and the light guide element and is used for toning the first light or the second light.

11. The backlight assembly of claim 10, wherein the dimming element comprises at least one of a wavelength conversion element and a color filter.

12. The backlight assembly of claim 1, wherein: the backlight assembly further includes a light source disposed at the light incident side of the first light guide structure.

13. A backlight assembly, comprising:

the first light guide structure comprises a light homogenizing part and a coupling-out part, wherein the light homogenizing part is used for homogenizing light from a light source;

the light splitting element is arranged on the light emitting side of the light homogenizing part so as to omit an adjusting element arranged on the light entering side of the first light guiding structure, the light splitting element is used for splitting the light subjected to light homogenizing treatment to obtain first light and second light, the first light is coupled to the second light guiding structure by the light splitting element, and the second light is transmitted to the second light guiding structure through the coupling-out part.

14. A backlight assembly, comprising:

the first light guide structure is used for homogenizing the incident light and transmitting the homogenized light to the second light guide structure;

a second light guiding structure comprising:

the light guide body is used for transmitting the light entering the second light guide structure;

15. An image source device, comprising:

the backlight assembly of any one of claims 1 to 14;

and a display panel for receiving light emitted from the backlight assembly and forming image light.

16. The image source device of claim 15, wherein the image source device further comprises at least one of:

a direction control element disposed between the backlight assembly and the display panel, for controlling a direction of light emitted from the backlight assembly so that the light emitted from the backlight assembly can be incident toward the display panel;

And the light diffusion element is arranged between the backlight assembly and the display panel and used for diffusing light coupled out of the backlight assembly.

17. A head-up display, comprising:

the image source device according to any one of claims 15 or 16, configured to emit image light;

and the display device is used for generating an imaging picture according to the image light.

18. A traffic device, comprising:

the heads-up display of claim 17 wherein the display is a display.

19. The traffic device of claim 18, wherein the display device is a windshield of the traffic device or a separately provided imaging plate.