Fresnel lens and cylindrical lens combined HUD backlight system

Abstract

The utility model relates to the technical field of HUD backlight systems, in particular to a Fresnel lens and cylindrical lens combined type HUD backlight system which comprises an LED lamp panel, a Fresnel collimating lens, a cylindrical lens and an LCD screen, the Fresnel collimating lens is cylindrical, the transmission face, facing the LED lamp panel, of the Fresnel collimating lens is a sawtooth Fresnel face, and the cylindrical lens is arranged on the LCD screen. The face, back to the LED lamp panel, of the Fresnel collimating lens is a plane, the focal length of the cylindrical lens is negative, the transmission face, facing the Fresnel collimating lens, of the cylindrical lens is a plane, the face, back to the Fresnel collimating lens, of the cylindrical lens is a concave face, and the LCD screen faces the concave face of the cylindrical lens. The technical problems that in the prior art, a large number of LED lamp beads need to be arranged for collimation through a total reflection lens, the light utilization rate is low, the collimation effect is poor, in addition, a high-cost fly-eye lens is needed for dodging in the follow-up process, and consequently the overall cost is high, and the effect is poor are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of HUD backlight systems, in particular to a Fresnel lens and cylindrical lens combined HUD backlight system. Background Art

[0002] A head-up display (HUD), also known as a head-up display, is an optical virtual image display system. Using reflection or refraction through optical lenses, this system presents various information related to the vehicle or aircraft's operation through a magnified virtual image directly in front of the driver's line of sight. The virtual image and the scenery appear simultaneously in the driver's field of view, allowing the driver to maintain their sightline on the road without having to look down at the instrument panel or center console. This effectively mitigates the aforementioned safety risks.

[0003] The existing technical solution is as follows: the light emitted by the LED lamp bead is relatively collimated by a total reflection lens, then uniformed by a compound eye lens, the uniformed light beam is angle-controlled by a plano-convex lens, and then the beam is deflected by a plane reflector. The deflected light beam is converged and shaped by a double convex lens, and finally enters the LCD screen through a diffuser.

[0004] The defects of the existing technology are: the light utilization rate of the total reflection lens is not very high, the collimation effect is not good, a lot of light will be wasted, and the number of LEDs used is large, so a compound eye lens is required. The processing of the compound eye lens is relatively complicated and the cost is relatively high. Summary of the Invention

[0005] In order to solve the technical problems in the existing technology that the use of total reflection lenses for collimation requires a large number of LED lamp beads, has low light utilization and poor collimation effect, and also requires high-cost compound eye lenses for subsequent light uniformity, resulting in high overall cost and poor effect, this application proposes a Fresnel lens and cylindrical lens combined HUD backlight system to solve the above technical problems.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] The utility model provides a Fresnel lens and cylindrical lens combined HUD backlight system, comprising: an LED light board; a Fresnel collimating lens, wherein the Fresnel collimating lens is cylindrical, the transmission surface of the Fresnel collimating lens facing the LED light board is a sawtooth Fresnel surface, and the surface of the Fresnel collimating lens facing away from the LED light board is a plane; a cylindrical lens, wherein the focal length of the cylindrical lens is negative, the transmission surface of the cylindrical lens facing the Fresnel collimating lens is a plane, and the surface of the cylindrical lens facing away from the Fresnel collimating lens is a concave surface; and an LCD screen, wherein the LCD screen faces the concave surface of the cylindrical lens.

[0008] Furthermore, the center of the Fresnel collimating lens is aligned with the center of the LED light board, and the extending direction of the Fresnel collimating lens is the same as the extending direction of the LED lamp beads on the LED light board.

[0009] Furthermore, the LCD screen is tilted to face the concave surface of the cylindrical lens.

[0010] Furthermore, five groups of lamp beads are arranged horizontally on the LED lamp board.

[0011] Furthermore, the saw teeth of the Fresnel collimating lens are saw teeth with equal depth and unequal width; or saw teeth with equal width and unequal depth.

[0012] Furthermore, the saw teeth of the Fresnel collimating lens have equal depths and the width of the saw teeth does not exceed 0.5 mm.

[0013] Based on the above technical solution, the technical effects that can be achieved by the present invention are:

[0014] The Fresnel lens and cylindrical lens combined HUD backlight system of the present invention uses a Fresnel lens and a cylindrical lens to collimate the light emitted by the LED light panel, thereby obtaining a relatively good collimation effect. The light is then expanded by the cylindrical lens to achieve an ideal beam angle and finally reaches the LCD screen for imaging, thereby replacing the total reflection lens and the compound eye lens. This solves the technical problems in the prior art of using total reflection lenses for collimation, which require a large number of LED lamp beads, have low light utilization rate, and poor collimation effect. In addition, a high-cost compound eye lens is required for subsequent light uniformity, resulting in high overall cost and poor effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of the Fresnel lens and cylindrical lens combined HUD backlight system of the present invention;

[0016] Figure 2 This is a schematic diagram of the LED light board of the present utility model;

[0017] Figure 3 This is a forward schematic diagram of the Fresnel collimating lens of the present invention;

[0018] Figure 4 This is a left side view of the Fresnel collimating lens of the present invention;

[0019] Figure 5 It is a left side view of the cylindrical lens of the present invention;

[0020] Figure 6 This is a partial optical path diagram of the Fresnel lens and cylindrical lens combined HUD backlight system of the present invention.

[0021] In the utility model: 1-LED light board, 11-LED lamp beads; 2-Fresnel collimating lens; 3-cylindrical lens; 4-LCD screen. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] like Figure 1-6 As shown, the utility model provides a HUD backlight system combined with a Fresnel lens and a cylindrical lens, comprising an LED light board 1, a Fresnel collimating lens 2, a cylindrical lens 3 and an LCD screen 4. The Fresnel collimating lens 2 is cylindrical, and the transmission surface of the Fresnel collimating lens 2 facing the LED light board 1 is a sawtooth Fresnel surface. The surface of the Fresnel collimating lens 2 facing away from the LED light board 1 is a plane. The focal length of the cylindrical lens 3 is negative, and the transmission surface of the cylindrical lens 3 facing the Fresnel collimating lens 2 is a plane. The surface of the cylindrical lens 3 facing away from the Fresnel collimating lens 2 is a concave surface. The LCD screen 4 faces the concave surface of the cylindrical lens 3.

[0024] In the Fresnel lens and cylindrical lens combined HUD backlight system of the present invention, the light emitted by the LED light board 1 is collimated by the Fresnel collimating lens 2 to obtain a relatively good collimation effect, and then the light is expanded by the cylindrical lens 3 to achieve an ideal beam angle and finally reach the LCD screen 4 for imaging, replacing the total reflection lens and the compound eye lens, thereby solving the technical problems in the prior art that the use of total reflection lenses for collimation requires a large number of LED lamp beads 11, has low light utilization rate and poor collimation effect, and further requires a high-cost compound eye lens for subsequent light uniformity, resulting in high overall cost and poor effect.

[0025] In a preferred embodiment of the present invention, the center of the Fresnel collimating lens 2 is aligned with the center of the LED light board 1, and the extension direction of the Fresnel collimating lens 2 is the same as the extension direction of the LED lamp beads 11 on the LED light board 1 to obtain a better focusing effect. The specific position relationship is as follows: Figure 2 Medium Fresnel collimating lens 2 with Figure 3 The middle LED light board 1 is facing.

[0026] In a preferred embodiment of the present invention, the LCD screen 4 is tilted to face the concave surface of the cylindrical lens 3 to prevent the LCD screen 4 from reflecting light.

[0027] In a preferred embodiment of the present invention, five groups of lamp beads are horizontally arranged on the LED lamp board 1 .

[0028] In the embodiment of the present invention, the saw teeth of the Fresnel collimating lens 2 are saw teeth with equal depth and unequal width; or saw teeth with equal width and unequal depth.

[0029] In a preferred embodiment of the present invention, the saw teeth of the Fresnel collimating lens 2 have equal depths and the width of the saw teeth does not exceed 0.5 mm.

[0030] It should be understood that the specific embodiments described above are only used to explain the present invention and are not intended to limit the present invention. Obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A Fresnel lens and cylindrical lens combined HUD backlight system, characterized in that: include: LED light board (1); A Fresnel collimating lens (2), wherein the Fresnel collimating lens (2) is cylindrical, the transmission surface of the Fresnel collimating lens (2) facing the LED light board (1) is a sawtooth Fresnel surface, and the surface of the Fresnel collimating lens (2) facing away from the LED light board (1) is a flat surface; a cylindrical lens (3), wherein the focal length of the cylindrical lens (3) is negative, the transmission surface of the cylindrical lens (3) facing the Fresnel collimating lens (2) is a plane, and the surface of the cylindrical lens (3) facing away from the Fresnel collimating lens (2) is a concave surface; An LCD screen (4), the LCD screen (4) faces the concave surface of the cylindrical lens (3).

2. The Fresnel lens and cylindrical lens combined HUD backlight system according to claim 1, characterized in that: The center of the Fresnel collimating lens (2) is aligned with the center of the LED light board (1), and the extension direction of the Fresnel collimating lens (2) is the same as the extension direction of the LED lamp beads (11) on the LED light board (1).

3. The Fresnel lens and cylindrical lens combined HUD backlight system according to claim 1, characterized in that: The LCD screen (4) is tilted and faces the concave surface of the cylindrical lens (3).

4. The Fresnel lens and cylindrical lens combined HUD backlight system according to claim 1, characterized in that: Five groups of lamp beads are arranged horizontally on the LED lamp board (1).

5. The Fresnel lens and cylindrical lens combined HUD backlight system according to claim 1, characterized in that: The saw teeth of the Fresnel collimating lens (2) are saw teeth of equal depth and unequal width; or saw teeth of equal width and unequal depth.

6. The Fresnel lens and cylindrical lens combined HUD backlight system according to claim 1, characterized in that: The saw teeth of the Fresnel collimating lens (2) have equal depths, and the width of the saw teeth does not exceed 0.5 mm.

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