Backlight module and head-up display

Abstract

This invention relates to a backlight module and a head-up display. The backlight module includes: an outer frame, a primary array lens, a secondary microstructure lens, and a lamp board. The lamp board has a mounting surface on which multiple LEDs are disposed. The primary array lens includes a primary carrier plate and multiple primary lenses disposed on the primary carrier plate. Each LED corresponds to a primary lens, and the corresponding primary lenses and LEDs are offset from each other in a direction perpendicular to the mounting surface. The side of the secondary microstructure lens facing the primary array lens is the light-incident surface, and several refractive surfaces inclined to the light-incident surface are recessed or raised on the light-incident surface. Because the primary lenses and corresponding LEDs are offset from each other, the light from the LEDs is projected and refracted by the primary lenses, resulting in lateral deflection. Combined with the inclined refractive surfaces on the secondary microstructure lens, the light emitted by the LEDs can be emitted at an angle, allowing the backlight module to match the tilt angle of the windshield without requiring tilting.

Description

Technical Field

[0001] This invention relates to the field of backlight technology, and in particular to a backlight module and a head-up display. Background Technology

[0002] PHUD (Panoramic Head-Up Display Backlight Module) is an automotive display solution that utilizes the black coated area at the bottom of the windshield to achieve an ultra-wide display from A-pillar to A-pillar through projection or screen reflection, replacing the traditional dashboard. PHUD relies on a high-performance backlight module to provide high brightness (peak values ​​of 7000–10000 nits), high contrast (millions of nits), and local dimming capabilities to cope with strong light environments and achieve a super-retina-level display effect.

[0003] Current automotive PHUDs employ a tilted placement design to adapt to the windshield's angle. While this achieves basic optical compatibility, the tilted placement causes secondary reflections, leading to light loss and reduced system luminous efficiency. To improve brightness, increased luminous power is required, resulting in higher power consumption, uneven heat flux distribution, and locally high temperatures. Therefore, the current tilted placement design for automotive PHUDs has significant drawbacks. Summary of the Invention

[0004] Therefore, it is necessary to provide a backlight module and a head-up display.

[0005] A backlight module includes: an outer frame, a primary array lens, a secondary microstructure lens, and a lamp panel;

[0006] An installation cavity is provided within the outer frame. The lamp panel, the primary array lens, and the secondary microstructure lens are sequentially arranged within the installation cavity. The lamp panel and the primary array lens are arranged adjacent to each other, and the secondary microstructure lens is arranged on the side of the primary array lens away from the lamp panel.

[0007] The lamp panel has a mounting surface on which a plurality of lamp beads are disposed. The mounting surface faces the primary array lens. The primary array lens includes a primary carrier plate and a plurality of primary lenses disposed on the primary carrier plate. Each lamp bead corresponds to a primary lens, and the projections of the corresponding primary lenses and the lamp beads on the mounting surface are offset from each other.

[0008] The side of the secondary microstructure lens facing the primary array lens is the light-incident surface, and the light-incident surface is provided with a plurality of refractive surfaces that are inclined to the light-incident surface, either recessed or raised.

[0009] In one embodiment, each of the primary lenses corresponds to at least two of the refractive surfaces, and the corresponding primary lenses and the refractive surfaces are offset from each other in a direction perpendicular to the mounting surface.

[0010] In one embodiment, the light-incident surface is provided with a plurality of V-shaped microstructures, each of the V-shaped microstructures having a refractive surface inclined to the light-incident surface.

[0011] In one embodiment, the two sides of each of the V-shaped microstructures are asymmetrical.

[0012] In one embodiment, each primary lens includes a convex lens and a concave lens, the convex lens and the concave lens being located on two opposite surfaces of the primary carrier plate, the concave lens facing the LED bead, and the convex lens facing the secondary microstructure lens, the central axis of the concave lens being offset from the central axis of the corresponding LED bead.

[0013] In one embodiment, the central axis of the convex lens and the central axis of the concave lens of the same primary lens are offset from each other.

[0014] In one embodiment, the central axis of the convex lens of the primary lens is offset from the central axis of the corresponding lamp bead.

[0015] In one embodiment, the central axis of the convex lens of each primary lens is located on one side of the central axis of the corresponding lamp bead, and the central axis of the concave lens is located on the other side of the central axis of the corresponding lamp bead.

[0016] In one embodiment, a diffusion film is further included, which is disposed on the side of the secondary microstructure lens away from the primary array lens.

[0017] A head-up display includes the backlight module described in any of the above embodiments.

[0018] The beneficial effects of this invention are as follows: Because the primary lens and the corresponding LED are staggered, the light from the LED is projected and refracted by the primary lens, resulting in a lateral deflection. This, combined with the refracting surface tilted on the secondary microstructure lens, allows the light emitted by the LED to ultimately exit at an angle towards the light panel. This eliminates the need for a tilted backlight module to match the windshield's angle, thus eliminating the mechanical tilting mechanism of traditional solutions. This effectively reduces the size of the backlight module and head-up display, minimizing space requirements and significantly lowering production costs. Furthermore, since the backlight module features its own tilted light emission, there is no need to increase power to avoid brightness loss due to secondary reflections, effectively reducing the backlight module's power consumption and preventing localized overheating. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a cross-sectional structural diagram of a backlight module according to an embodiment;

[0021] Figure 2 This is a partial cross-sectional structural diagram of a backlight module according to an embodiment;

[0022] Figure 3 This is a cross-sectional view of a secondary microstructure lens and a schematic diagram showing the light emission direction, according to one embodiment.

[0023] Figure 4 This is a schematic diagram of the light emission direction in the first direction, showing the cross-sectional structure of the primary lens and the LED in one embodiment.

[0024] Figure 5 This is a schematic diagram of the light emission direction in the second direction, showing the cross-sectional structure of the primary lens and the LED in one embodiment.

[0025] Figure 6 This is a top view schematic diagram of the primary lens and LED chip in one embodiment.

[0026] Explanation of reference numerals in the attached figures:

[0027] 10. Backlight module; 100. Primary array lens; 200. Secondary microstructure lens; 300. Outer frame; 400. Lamp board; 301. Mounting cavity; 410. Mounting surface; 500. Lamp bead; 110. Primary carrier plate; 120. Primary lens; 210. Secondary carrier plate; 220. Light-transmitting microstructure; 221. Refractive surface; 121. Convex lens; 122. Concave lens; 600. Diffuser film; 310. Face frame; 320. Bottom shell; 311. Light outlet; 123. Smooth transmission section. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figure 1 and Figure 2 As shown, it is a backlight module 10 according to an embodiment of the present invention, including: an outer frame 300, a primary array lens 100, a secondary microstructure lens 200, and a lamp panel 400;

[0030] An installation cavity 301 is provided inside the outer frame 300. The lamp panel 400, the primary array lens 100 and the secondary microstructure lens 200 are sequentially arranged in the installation cavity 301. The lamp panel 400 and the primary array lens 100 are arranged adjacent to each other. The secondary microstructure lens 200 is arranged on the side of the primary array lens 100 away from the lamp panel 400.

[0031] The lamp panel 400 has a mounting surface 410 on which a plurality of lamp beads 500 are disposed. The mounting surface 410 faces the primary array lens 100. The primary array lens 100 includes a primary carrier plate 110 and a plurality of primary lenses 120 disposed on the primary carrier plate 110. Each lamp bead 500 corresponds to a primary lens 120, and the projections of the corresponding primary lenses 120 and the lamp beads 500 on the mounting surface 410 are offset from each other.

[0032] The side of the secondary microstructure lens 200 facing the primary array lens 100 is the light-incident surface, and a plurality of refractive surfaces 221 inclined to the light-incident surface are provided on the light-incident surface, either recessed or raised.

[0033] In this embodiment, the outer frame 300 provides support and protection, and the mounting cavity 301 supports the lamp board 400, the primary array lens 100, and the secondary microstructure lens 200. Specifically, the edges of the lamp board 400, the primary carrier plate 110, and the secondary carrier plate 210 can be fixedly connected to the inner side of the outer frame 300 by screws or snap-fit ​​structures, thereby realizing the installation of the lamp board 400, the primary array lens 100, and the secondary microstructure lens 200. The mounting cavity 301 has a light outlet 311, which is located at the end of the outer frame 300 away from the lamp board 400. The mounting surface 410 of the lamp board 400 faces the light outlet 311, so that the light emitted by the lamp beads 500 on the lamp board 400 passes through the primary array lens 100 and the secondary microstructure lens 200 in sequence and exits outside the light outlet 311. In this embodiment, the lamp beads 500 are LED (light-emitting diode) lamp beads 500.

[0034] In this embodiment, since the projection of the LED 500 on the mounting surface 410 and the projection of the primary lens 120 on the mounting surface 410 are offset from each other, the primary lens 120 generates polarized light, causing the light to deflect. The refractive surface 221 on the secondary microstructure lens 200 is tilted, which can refract the deflected light at an angle, thereby achieving tilted light output. In this way, there is no need to configure a mechanical tilting structure, which effectively reduces the volume of the backlight module 10 and reduces the space occupied by the backlight module 10 in the vehicle.

[0035] In the above embodiment, because the primary lens 120 and the corresponding LED 500 are staggered, the light from the LED 500 is projected and refracted by the primary lens 120, resulting in a lateral deflection. This, combined with the refracting surface 221 tilted on the secondary microstructure lens 200, allows the light emitted by the LED 500 to ultimately exit at an angle towards the lamp panel 400. This eliminates the need for the backlight module 10 to be tilted to match the windshield's angle, thus eliminating the mechanical tilting mechanism of traditional solutions. This effectively reduces the size of the backlight module 10 and the head-up display, minimizing space requirements and lowering the production cost of the backlight module 10. Furthermore, since the backlight module 10 has its own tilted light emission, there is no need to increase power to avoid brightness loss due to secondary reflections, effectively reducing the power consumption of the backlight module 10 and preventing localized overheating.

[0036] In one embodiment, each of the primary lenses 120 corresponds to at least two of the refractive surfaces 221, and the primary lenses 120 and the refractive surfaces 221 that have a corresponding relationship are offset from each other in a direction perpendicular to the mounting surface 410.

[0037] In this embodiment, the light emitted by each LED 500 is refracted at an angle by the corresponding primary lens 120 and then emitted toward two or more refractive surfaces 221. Each LED 500 and each primary lens 120 corresponds to one or more refractive surfaces 221, and these corresponding refractive surfaces 221 are offset from the corresponding LED 500 and primary lens 120 in a direction perpendicular to the mounting surface 410. This allows the refractive surfaces 221 to fully receive the light transmitted by the corresponding primary lens 120, resulting in more effective angled light emission.

[0038] In one embodiment, such as Figure 3 As shown, the light-incident surface is provided with a plurality of V-shaped microstructures, and each of the V-shaped microstructures has a refractive surface 221 inclined to the light-incident surface.

[0039] In this embodiment, the light-incident surface of the secondary microstructure lens 200 has multiple light-transmitting microstructures 220, which are V-shaped microstructures. In this embodiment, the secondary microstructure lens 200 includes a secondary carrier plate 210 and light-transmitting microstructures 220. The secondary carrier plate 210 is connected to the outer frame 300, and the side of the secondary carrier plate 210 facing the primary carrier plate 110 is the light-incident surface. The light-transmitting microstructures 220 are disposed on the light-incident surface of the primary carrier plate 110.

[0040] Specifically, in this embodiment, the V-shaped microstructures are arranged sequentially to form a sawtooth structure, which allows light to be transmitted and refracted to the light outlet 311 at the required angle. In one embodiment, the two sides of each V-shaped microstructure are asymmetrical. In one embodiment, one side of the V-shaped microstructure is a refractive surface 221, and the other side is a reflective surface. The refractive surface 221 and the reflective surface are asymmetrical about the central axis of the V-shaped microstructure. Thus, by utilizing the reflection of the reflective surface, light can be concentrated and reflected in the direction refracted by the refractive surface 221, thereby improving brightness and avoiding light loss caused by transmission and refraction of the reflective surface. To achieve reflection of the reflective surface, in one embodiment, the reflective surface of the V-shaped microstructure is provided with a reflective coating, which makes the reflection of the reflective surface more sufficient. It is worth mentioning that the reflective coating is provided on the inner side of the reflective surface of the V-shaped microstructure, so that it can reflect more effectively in the direction of the refractive surface 221.

[0041] In one embodiment, such as Figure 3 As shown, the secondary microstructure lens 200 has multiple arc-shaped surfaces on the side facing away from the primary carrier plate 110. By setting the arc-shaped surfaces, light can be further diffused, and light rays with different incident angles can be further refracted into collimated beams, making the outgoing light more uniform.

[0042] In one embodiment, please combine Figure 2 and Figure 4 Each of the primary lenses 120 includes a convex lens 121 and a concave lens 122. The convex lens 121 and the concave lens 122 are located on two opposite surfaces of the primary carrier plate 110. The concave lens 122 faces the lamp bead 500, and the convex lens 121 faces the secondary microstructure lens 200. The central axis of the concave lens 122 is offset from the central axis of the corresponding lamp bead 500.

[0043] In this embodiment, each primary lens 120 includes an integral convex lens 121 and a concave lens 122. The convex lens 121 protrudes towards the secondary microstructure lens 200, while the concave lens 122 is recessed away from the LED bead 500. Both the convex lens 121 and the concave lens 122 have arc-shaped cross-sections. It is worth noting that in all embodiments, the central axis of the LED bead 500, the central axis of the convex lens 121, and the central axis of the concave lens 122 are all perpendicular to the mounting surface 410. Because the central axis of the concave lens 122 is offset from the central axis of the LED bead 500, the light emitted by the LED bead 500 is refracted by the offset concave lens 122, resulting in offset and tilted light emission.

[0044] To ensure that the light from the LED 500 is sufficiently deflected and tilted after passing through the primary lens 120, in one embodiment, such as... Figure 4 As shown, the central axis of the convex lens 121 and the central axis of the concave lens 122 of the same primary lens 120 are offset from each other.

[0045] In this embodiment, the central axis of the convex lens 121 and the central axis of the concave lens 122 are perpendicular to the mounting surface 410. Each primary lens 120 is asymmetrical in shape, and the convex lens 121 and concave lens 122 of each primary lens 120 are offset from each other. In this way, when the concave lens 122 receives the light from the lamp bead 500, it needs to undergo lateral refraction and offset before it can be transmitted out through the convex lens 121, thereby forming a lateral offset tilted light output and achieving a better tilted emission effect.

[0046] In one embodiment, the projection shape of the primary lens 120 onto the primary carrier plate 110 is elliptical. In this embodiment, the elliptical structure of the primary lens 120, compared with the traditional circular lens light-emitting structure, can effectively improve the edge brightness uniformity, while avoiding the central bright spot of the circular structure, resulting in more uniform light emission and better display effect.

[0047] In one embodiment, please see again Figure 4 The central axis of the convex lens 121 of the primary lens 120 is offset from the central axis of the corresponding lamp bead 500.

[0048] In this embodiment, the central axis of the convex lens 121 and the central axis of the lamp bead 500 are perpendicular to the mounting surface 410. This allows the projection of the convex lens 121 of the first-stage lens 120 onto the mounting surface 410 and the projection of the lamp bead 500 onto the mounting surface 410 to be staggered. Thus, due to the lateral offset between the convex lens 121 and the lamp bead 500, the light from the lamp bead 500 can be effectively refracted at an angle.

[0049] In one embodiment, please see again Figure 4 The central axis of the convex lens 121 of each primary lens 120 is located on one side of the central axis of the corresponding lamp bead 500, and the central axis of the concave lens 122 is located on the other side of the central axis of the corresponding lamp bead 500.

[0050] In this embodiment, the central axis of the convex lens 121, the central axis of the concave lens 122, and the central axis of the lamp bead 500 are all perpendicular to the mounting surface 410. In this embodiment, the central axes of the convex lens 121 and the concave lens 122 of the same first-stage lens 120 are located on both sides of the central axis of the corresponding lamp bead 500. This is beneficial for fully covering the lamp bead 500, effectively refracting and transmitting the light from the lamp bead 500, and better lateral offset and tilt refraction of the light from the lamp bead 500. It is worth mentioning that if the central axis of the convex lens 121 and the central axis of the concave lens 122 of the first-stage lens 120 are both located on the same side of the central axis of the corresponding lamp bead 500, it is equivalent to the first-stage lens 120 being offset from the lamp bead 500. In this way, although the light emitted by the lamp bead 500 can also produce a tilted emission effect, the refraction directions between the lamp beads 500 are parallel to each other, and the light transmitted by each first-stage lens 120 is relatively independent, resulting in more obvious bright and dark stripes between the lamp beads 500. The combination of the convex lens 121 and the concave lens 122 has a more obvious focusing effect on the light of the corresponding lamp bead 500, thus further aggravating the obvious brightness and darkness between the lamp beads 500. Therefore, in this embodiment, the central axis of the convex lens 121 and the central axis of the concave lens 122 of the same first-stage lens 120 are located on both sides of the central axis of the corresponding lamp bead 500, so that the concave lens 122 can absorb light from a position more biased towards the first side of the lamp bead 500 and diffuse the light to the convex lens 121 which is closer to the second side, thus achieving oblique refraction of light. Furthermore, this structure makes the concave lens 122 closer to the convex lens 121 of the adjacent first-stage lens 120, so that the light emitted from the two adjacent first-stage lenses 120 is closer and interlaced, effectively reducing the obviousness of bright and dark stripes and reducing the intensity of light and dark contrast. This achieves oblique light emission while making the light output more uniform and effectively weakening the intensity of light and dark contrast.

[0051] In one embodiment, the width of the convex lens 121 is greater than the width of the concave lens 122. This allows the convex lens 121 to fully cover the LED 500, and also allows the light from the LED 500 to be diffused over a wider area, thus improving the uniformity of the backlight.

[0052] In one embodiment, such as Figure 4As shown, the central axis of the convex lens 121 of each primary lens 120 is located on one side of the central axis of the corresponding lamp bead 500, and the distance between the central axis of the convex lens 121 and the central axis of the corresponding lamp bead 500 is L2. The central axis of the concave lens 122 is located on the other side of the central axis of the corresponding lamp bead 500, and the distance between the central axis of the concave lens 122 and the central axis of the corresponding lamp bead 500 is L1, L2=L1. The distance between the central axis of the convex lens 121 and the central axis of the concave lens 122 of the same primary lens 120 is L3, where L3=L2+L1.

[0053] In this embodiment, the central axes of the convex lens 121 and the concave lens 122 are symmetrically arranged about the central axis of the corresponding LED bead 500. However, the widths of the convex lens 121 and the concave lens 122 are different. For example, the width of the convex lens 121 is greater than the width of the concave lens 122, and the curvature of the convex lens 121 is different from that of the concave lens 122. This means that the convex lens 121 and the concave lens 122 are not completely symmetrical about the central axis of the LED bead 500, but only their central axes are symmetrical about the central axis of the LED bead 500. With this configuration, the concave lens 122 is responsible for the initial focusing and deflection, while the convex lens 121 performs the second refraction and collimates and guides the light. The symmetrical setting of the central axis L2 = L1 ensures the symmetry and consistency of light refraction, so that the light emitted from each LED 500 has a highly consistent tilt angle and directionality, and allows the light from adjacent primary lenses 120 to interleave, greatly weakening the contrast between light and dark.

[0054] It is worth mentioning that, in this embodiment, as Figure 4As shown, the width of the convex lens 121 is greater than the width of the concave lens 122, so that the projection of the edge of the concave lens 122 on the mounting surface 410 is intersected or adjacent to the projection of the convex lens 121 of the other first-stage lens 120 on the mounting surface 410. In this way, the convex lens 121 and the concave lens 122 of the two adjacent first-stage lenses 120 are intersected or adjacent to each other, so that the range of the incident light of the lamp bead 500 is intersected with the range of the emitted light of the adjacent lamp bead 500, thereby realizing that the light of the adjacent lamp beads 500 can be intersected, greatly weakening the contrast between light and dark. It should be understood that this structure achieves the interleaving of the convex lenses 121 and concave lenses 122 of two adjacent primary lenses 120, rather than simply interleaving the two primary lenses 120 with each other. The reason is that the convex lenses 121 of two adjacent primary lenses 120 cannot be simply interleaved. If the convex lenses 121 of two adjacent primary lenses 120 are forcibly interleaved, the curvature of the two adjacent convex lenses 121 will be insufficient, resulting in them becoming flat and unable to form a light-gathering effect, thus preventing the convex lenses 121 from playing their due role. Similarly, the concave lenses 122 of two adjacent primary lenses 120 cannot be simply interleaved. Excessive interleaving of the concave lenses 122 will also result in insufficient curvature of the concave lenses 122, resulting in them becoming flat. Therefore, in this embodiment, convex lenses 121 and concave lenses 122 that are not intersected in the longitudinal direction are used, but are intersected in the transverse direction, so that two adjacent first-stage lenses 120 are intersected, thereby achieving the intersecting of light emission and weakening the contrast between adjacent lamp beads 500.

[0055] In one embodiment, the ratio of the chord length of the convex lens 121 to the chord length of the concave lens 122 is (1.2~1.4):1. Preferably, the ratio is 1.3:1, and the distance between the central axis of the convex lens 121 and the central axis of the concave lens 122 of the same first-stage lens 120 is L3. The difference in length is D1, where 1 / 2D1 < L3 < D1. In this embodiment, the chord length of the convex lens 121 refers to the chord length of the convex arc portion of the convex lens 121, that is, the length of the projection of the convex arc portion of the convex lens 121 onto the mounting surface 410. The chord length of the concave lens 122 refers to the chord length of the concave arc portion of the concave lens 122, that is, the length of the projection of the concave arc portion of the concave lens 122 onto the mounting surface 410. The distance L3 between the central axes of the convex lens 121 and the concave lens 122 is less than the difference D1 between the chord lengths of the convex lens 121 and the concave lens 122, and greater than half of the distance D1 between the central axes of the convex lens 121 and the concave lens 122. This causes the concave lens 122 to shift towards the center of the convex lens 121, and the edge of the concave lens 122 can extend to the outer edge of the convex lens 121, so that the concave lens 122 can intersect with the convex lens 121 of the other first-stage lens 120. In this way, the light from the two adjacent first-stage lenses 120 can be refracted out in an interlaced manner, thereby weakening the contrast between the brightness and darkness of the adjacent lamp beads 500. It is worth mentioning that the overlap between the concave lens 122 and the convex lens 121 of adjacent primary lenses 120 should not be too large. For example, if the concave lens 122 extends too far into the range of the adjacent convex lens 121, the convex lens 121 of the same primary lens 120 as the concave lens 122 will not be able to fully refract and focus the light, resulting in poor tilting emission effect. On the other hand, if the overlap between the concave lens 122 and the convex lens 121 of adjacent primary lenses 120 is too small, the light from adjacent LEDs 500 will be relatively independent, resulting in dark lines between the light from adjacent LEDs 500, thus forming a more obvious light-dark slit and producing a more obvious contrast between light and dark. Therefore, in this embodiment, the ratio of the chord length of the convex lens 121 to the chord length of the concave lens 122 is 1.3:1, which allows the concave lens 122 to be offset relative to the convex lens 121, providing space for the offset of the concave lens 122. In addition, with 1 / 2D1 < L3 < D1, the intersection range of adjacent concave lenses 122 and convex lenses 121 can be maximized, thereby more effectively weakening the contrast between light and dark, reducing the light and dark gap, and effectively maintaining the tilted refraction effect of the first-stage lens 120 on the lamp bead 500, making the tilted refraction effect better.

[0056] It is worth mentioning that the LEDs 500 on the lamp panel 400 of the backlight module 10 are arranged in a multi-row, multi-column array, and the primary lens 120 corresponding to the LEDs 500 is also arranged in a multi-row, multi-column array. Since multiple primary lenses 120 are arranged in both the horizontal and vertical directions, in order to avoid the light from the backlight module 10 tilting in different directions and to ensure that the light from the backlight module 10 is emitted only in one direction, in one embodiment, please refer to... Figures 4 to 6 The central axis of the convex lens 121 of each primary lens 120 is located on one side of the central axis of the corresponding lamp bead 500 in the first direction, and the distance between the central axis of the convex lens 121 and the central axis of the corresponding lamp bead 500 in the first direction is L2. The central axis of the concave lens 122 is located on the other side of the central axis of the corresponding lamp bead 500 in the first direction, and the distance between the central axis of the concave lens 122 and the central axis of the corresponding lamp bead 500 in the first direction is L1, L2=L1. The distance between the central axis of the convex lens 121 and the central axis of the concave lens 122 of the same primary lens 120 in the first direction is L3, where L3=L2+L1. The central axis of the convex lens 121 and the central axis of the concave lens 122 of each primary lens 120 coincides with the central axis of the lamp bead 500 in the second direction. The first direction and the second direction are perpendicular to each other, and both the first direction and the second direction are parallel to the mounting surface 410. In this embodiment, the width of the convex lens 121 in the first direction is greater than the width of the concave lens 122 in the first direction, and the ratio of the chord length of the convex lens 121 in the first direction to the chord length of the concave lens 122 in the first direction is 1.3:1. The difference between the chord length of the convex lens 121 in the first direction and the chord length of the concave lens 122 in the first direction is D1, where 1 / 2D1 < L3 < D1. The width of the convex lens 121 in the second direction is greater than the width of the concave lens 122 in the second direction.

[0057] In this embodiment, the convex lens 121 and the concave lens 122 are offset from each other in the first direction and are also offset from the LED 500, so that the light emitted by the LED 500 can be obliquely emitted from the surface of the backlight module 10. For example, when the backlight module 10 is installed on a vehicle, the first direction is the front of the vehicle. In this way, the backlight module 10 can obliquely emit light in the front, so that the backlight module 10 can emit light obliquely without being obliquely installed. The convex lens 121, the concave lens 122 and the LED 500 are aligned with each other in the second direction, so that the backlight module 10 will not be oblique in the second direction. For example, the second direction is the left and right direction of the vehicle. In this way, the obliqueness of the backlight module 10 in the left and right direction is avoided, so that the backlight module 10 can focus on the front for oblique projection. Furthermore, since the width of the convex lens 121 in the first direction is greater than the width of the concave lens 122 in the first direction, and the central axes of the convex lens 121 and the concave lens 122 are offset in the first direction, the projection of the edge of the concave lens 122 on the mounting surface 410 in the first direction is intersected or adjacent to the projection of the convex lens 121 of the other first-stage lens 120 on the mounting surface 410, thereby effectively weakening the contrast between light and dark emitted by the backlight module 10 in the first direction.

[0058] In order to reduce the contrast between light and dark in the backlight module 10 in the second direction, in one embodiment, such as Figure 5 As shown, a smooth transmission section 123 is provided between the convex lens 121 of each primary lens 120 and the convex lens 121 of the other primary lens 120 adjacent in the second direction. The smooth transmission section 123 has an arcuate structure. The chord length of the smooth transmission section 123 in the second direction is less than the chord length of the convex lens 121, and the curvature of the smooth transmission section 123 is less than the curvature of the convex lens 121. For example, the chord length of the smooth transmission section 123 in the second direction is less than or equal to one-quarter of the chord length of the convex lens 121, and greater than one-sixth of the chord length of the convex lens 121. The height of the smooth transmission section 123 protruding from the primary carrier plate 110 is less than one-fifth of the height of the convex lens 121 protruding from the primary carrier plate 110.

[0059] In this embodiment, two adjacent convex lenses 121 are connected in the second direction by a smooth transmission section 123, so that the light between the two adjacent convex lenses 121 can be emitted through the smooth transmission section 123. It should be understood that since the convex lens 121 has a light-focusing effect, by providing a smooth transmission section 123 between the two adjacent convex lenses 121, the light-focusing range of the convex lens 121 in the second direction is reduced, and the slightly raised arc surface of the smooth transmission section 123 can also play a slight light-focusing role, making up for the dark gap between the adjacent convex lenses 121 in the second direction. It should be understood that in this embodiment, the primary lens 120 employs different structures for weakening the light and dark slits in the first and second directions. In the first direction, since the light needs to be emitted at an angle, the convex lens 121 and the concave lens 122 need to be staggered in the first direction. In this staggered structure, to weaken the contrast between light and dark, adjacent convex lenses 121 and concave lenses 122 are interleaved, so that the focusing ranges are interleaved, thereby weakening the contrast between light and dark. In the second direction, since the central axes of the convex lenses 121 and concave lenses 122 are not staggered, and the width of the convex lens 121 is greater than that of the concave lens 122, adjacent convex lenses 121 and concave lenses 122 cannot be interleaved. Therefore, a smooth transmission section 123 with a relatively small arc and curvature is used to compensate for the dark slits between adjacent convex lenses 121. The brightness is reduced, thus weakening the contrast between light and dark in the second direction. Furthermore, the structure of the smooth transmission section 123 is not suitable for the structure between the convex lenses 121 in the first direction. The specific reason is as mentioned above: if the smooth transmission section 123 is used to connect the convex lenses 121 in the first direction, the convex lenses 121 will be too flat in the first direction and will not achieve a good light-gathering effect. However, in the second direction, there is no need for excessive light gathering. Therefore, the smooth transmission section 123 can be used in the second direction. In this way, the backlight module 10 can produce tilted light emission in the first direction, and the emitted light brightness is high and more concentrated, and the contrast between light and dark in the first direction is greatly weakened. In the second direction, the light emission is uniform, and the contrast between light and dark can also be greatly weakened, thus making the overall light emission effect of the backlight module 10 better.

[0060] In one embodiment, such as Figure 2 As shown, the outer frame 300 includes a face frame 310 and a bottom shell 320. The face frame 310 and the bottom shell 320 are connected, and an inner mounting cavity 301 is formed. The lamp plate 400 is mounted on the bottom shell 320. The secondary microstructure lens 200 is disposed on the side close to the face frame 310. The face frame 310 is provided with a light outlet 311.

[0061] In this embodiment, the bottom shell 320 is made of aluminum alloy, and the face frame 310 is made of plastic. The aluminum alloy bottom shell 320 has high hardness and good thermal conductivity, which can effectively absorb the heat emitted by the lamp panel 400. The face frame 310 is made of plastic, which can effectively reduce the weight of the backlight module 10 and achieve lightweighting. In this embodiment, the light outlet 311 is located on the face frame 310, so that the light emitted by the lamp bead 500 is transmitted through the primary array lens 100 and the secondary microstructure lens 200 and emitted from the light outlet 311 of the face frame 310.

[0062] To improve light emission uniformity, in one embodiment, such as Figure 2 As shown, the backlight module 10 also includes a diffusion film 600, which is disposed on the side of the secondary microstructure lens 200 away from the primary array lens 100.

[0063] In this embodiment, by providing a diffusion film 600 within the backlight module 10, the light passing through the secondary microstructure lens 200 can be diffused more uniformly. It is worth noting that in this embodiment, the secondary microstructure lens 200 not only performs tilted refraction but also homogenizes the light, effectively reducing the gaps between the LEDs 500 and the surrounding light. The diffusion film 600 further diffuses and disperses the light, further reducing the gaps between the LEDs 500 and the surrounding light, resulting in better uniformity of the backlight module 10 and effectively improving image quality.

[0064] In one embodiment, a head-up display is provided, including the backlight module 10 described in any of the above embodiments.

[0065] In this embodiment, the primary array lens 100 is responsible for collecting the light emitted by the LED beads 500 and effectively controlling it within the designed spatial angle range. The light passes through the V-shaped microstructure of the microstructure lens, which refracts light at different incident angles into collimated beams. The collimated light is then homogenized by the diffusion film 600. In this embodiment, the surface morphology of the V-shaped microstructure is optimized to ensure optical matching with the diffusion film 600, ultimately resulting in uniform light being perpendicularly incident on the TFT (Thin Film Transistor) display panel.

[0066] In this embodiment, the lens structure features are as follows: the primary array lens 100 is laterally deflected, and the secondary microstructure lens 200 is longitudinally deflected, forming a double-stage lens deflection arrangement. This supports gradient refraction, enabling more precise beam control and accurately deflecting the collected light to the target direction. The lens angle can be adjusted according to the specific vehicle model requirements to achieve a polarization effect, allowing for precise and efficient projection onto the windshield. The backlight module 10 of this application, through a precise optical structure configuration, achieves efficient optical path control from the light source to the display panel, ensuring optical performance while providing flexible design freedom.

[0067] In this embodiment, the light-incident surface of the secondary microstructure lens 200 adopts a V-shaped microstructure. The V-shaped microstructure adopts an asymmetric surface shape to achieve active deflection of the incident light path and reduce the secondary reflection loss of the traditional tilted structure.

[0068] In addition, the first-stage lens 120 light-emitting surface adopts an olive-shaped structure. The olive-shaped light-emitting surface is optimized by using an elliptical curved surface design, which improves the uniformity of edge illumination compared to the traditional circular light-emitting surface, while avoiding the bright spot in the center of the circular structure.

[0069] The LED chips 500 and the primary lens 120 are arranged in an alternating pattern. The LED chips 500 and the primary lens 120 are arranged in an alternating pattern. Compared with the traditional orthogonal lens arrangement, this arrangement can ensure that the entire system can be placed normally without having to be tilted according to the vehicle model and the tilt angle of the windshield.

[0070] The dual-stage lens offset arrangement of the primary array lens 100 and the secondary microstructure lens 200 enables the formation of a three-dimensional optical path compensation by achieving primary lateral offset and secondary longitudinal offset.

[0071] In this application, the backlight module 10 features a structural paradigm innovation by adopting adaptive optical path compensation: the polarization structure unit dynamically matches the windshield tilt angle, eliminating the mechanical tilting mechanism of traditional solutions.

[0072] This application represents a technological and economic breakthrough: increased space utilization. Traditional systems require tilting angles, resulting in large space requirements; this new system perfectly solves this problem.

[0073] In this application, the energy efficiency ratio is optimized: while maintaining the same brightness, the system power consumption is reduced and the uniformity of heat flux density distribution is improved.

[0074] This application employs a technical approach that replaces mechanical compensation with a combination of microstructure and misaligned arrangement for optical calibration, achieving the following while maintaining windshield adaptability:

[0075] A leap in light efficiency;

[0076] The overall cost is reduced by more than 50% compared to traditional solutions;

[0077] Space utilization optimization reaches the best level in the industry;

[0078] This application not only resolves the inherent energy efficiency and cost contradiction of tilted structures, but also establishes a new technical standard for PHUD backlight modules: "high luminous efficiency, low cost, and small size," providing a mass-producible optimization solution for the iteration of intelligent cockpit display systems.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A backlight module, characterized in that, include: Outer frame, primary array lens, secondary microstructure lens and lamp panel; An installation cavity is provided within the outer frame. The lamp panel, the primary array lens, and the secondary microstructure lens are sequentially arranged within the installation cavity. The lamp panel and the primary array lens are arranged adjacent to each other, and the secondary microstructure lens is arranged on the side of the primary array lens away from the lamp panel. The lamp panel has a mounting surface on which a plurality of lamp beads are disposed. The mounting surface faces the primary array lens. The primary array lens includes a primary carrier plate and a plurality of primary lenses disposed on the primary carrier plate. Each lamp bead corresponds to a primary lens, and the projections of the corresponding primary lenses and the lamp beads on the mounting surface are offset from each other. The side of the secondary microstructure lens facing the primary array lens is the light-incident surface, and a plurality of refractive surfaces inclined to the light-incident surface are provided on the light-incident surface, either recessed or raised. Each of the first-stage lenses includes a convex lens and a concave lens, the convex lens and the concave lens being located on two opposite surfaces of the first-stage carrier plate, the concave lens facing the lamp bead, the convex lens facing the second-stage microstructure lens, and the central axis of the concave lens being offset from the central axis of the corresponding lamp bead. The central axis of the convex lens of each primary lens is located on one side of the central axis of the corresponding LED bead in a first direction, and the distance between the central axis of the convex lens and the central axis of the corresponding LED bead in the first direction is L2. The central axis of the concave lens is located on the other side of the central axis of the corresponding LED bead in the first direction, and the distance between the central axis of the concave lens and the central axis of the corresponding LED bead in the first direction is L1, where L2 = L1. The distance between the central axis of the convex lens and the central axis of the concave lens of the same primary lens in the first direction is L3, where L3 = L2 + L1. The central axes of the convex lens and the concave lens of each primary lens are located on the other side of the central axis of the corresponding LED bead in the first direction. The second direction coincides with the central axis of the lamp bead, wherein the first direction and the second direction are perpendicular to each other, and both the first direction and the second direction are parallel to the mounting surface. The width of the convex lens in the first direction is greater than the width of the concave lens in the first direction, such that the projection of the edge of the concave lens on the mounting surface intersects or is adjacent to the projection of the convex lens of another first-stage lens on the mounting surface. The ratio of the chord length of the convex lens in the first direction to the chord length of the concave lens in the first direction is 1.3:1, and the difference between the chord length of the convex lens in the first direction and the chord length of the concave lens in the first direction is D1, wherein 1 / 2D1 < L3 < D1. The width of the convex lens in the second direction is greater than the width of the concave lens in the second direction.

2. The backlight module according to claim 1, characterized in that, Each of the primary lenses corresponds to at least two of the refractive surfaces, and the primary lenses and the refractive surfaces that have a corresponding relationship are offset from each other in a direction perpendicular to the mounting surface.

3. The backlight module according to claim 1, characterized in that, The light-incident surface is provided with a plurality of V-shaped microstructures, each of which has a refractive surface inclined to the light-incident surface.

4. The backlight module according to claim 3, characterized in that, Each of the V-shaped microstructures has two asymmetrical sides.

5. The backlight module according to any one of claims 1-4, characterized in that, It also includes a diffusion film, which is disposed on the side of the secondary microstructure lens away from the primary array lens.

6. A heads-up display, characterized in that, Includes the backlight module as described in any one of claims 1-5.

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