CN108957621A - A kind of annular light guide plate and automobile instrument mould group - Google Patents

Abstract

The invention discloses a kind of annular light guide plate and automobile instrument mould groups, light guide plate includes substrate, perforation is provided in the middle part of substrate, protrusion is extended with to the back side of substrate at the edge of perforation centered on the perforation, the end face of substrate is provided with the first light diffusing unit in protrusion, the knee that substrate extends protrusion is provided with the second light diffusing unit；Light source enters light guide plate from the first light diffusing unit, and the front of substrate is diffused into from the second light diffusing unit.The present invention not only can guarantee backlighting effect and illuminate range, moreover it is possible to reduce the usage quantity of LED, save the cost is more reasonably utilized limited space in automobile, to meet the labyrinth demand of automobile instrument.

Description

A ring-shaped light guide plate and an automobile instrument module

technical field

The invention relates to the technical field of light guide plates, in particular to an annular light guide plate and an automobile instrument module.

Background technique

LED backlight technology is widely used in automotive interior lighting because of its long service life and low power consumption. The common backlight structure is to fix and weld the LED PCB on one or both sides of the light guide plate. When the light beam emitted by the LED passes through the zigzag mesh and cylindrical dots on the light guide plate, it will be evenly distributed on the light guide plate. . However, this method is only applicable to the conventional backlight structure with a structural shape. When the structure of the automotive instrument is complex, the ordinary backlight structure usually encounters problems in brightness, uniformity, and LED arrangement position. It is difficult to achieve the ideal display effect.

As shown in the figure, a space of about 7mm needs to be reserved for placing LEDs in conventional backlights, and the bright spots of the LED lamp eyes enter the visible area, which limits the requirements for the shape and structure of the backlight. It will inevitably have an impact, and the product shape is forced to increase, which affects the appearance.

As shown in Figure 1, the front serrations of conventional backlights are small and dense. In order to disperse the light evenly before reaching the visible area of the light guide plate and make the brightness of the visible area of the light guide plate uniform, the pitch of the teeth generally does not exceed 0.1mm.

As shown in Figure 1, conventional backlights are placed on one side without special requirements due to the consideration of the size requirements, so the side with LEDs has higher brightness, and the side without LEDs has lower brightness, so the uniformity is poor, generally only The uniformity of 65%~75% is achieved, and the display effect is sometimes unsatisfactory.

As shown in Figure 2, if you encounter a backlight similar to a car dashboard structure, you need to hollow out the middle and assemble other light-proof components. LEDs are added around the backlight, and the use of LEDs and PCBs is large, which is not ideal in terms of cost and structural size, and because of the large number of LEDs, the brightness will be higher. For products, the brightness of the backlight cannot be effectively controlled within the required range under low power consumption.

Therefore, there is an urgent need to design a backlight technology for automotive instrumentation, which can not only ensure the lighting effect and illumination range of the backlight, but also reduce the number of LEDs used and save costs. Make more reasonable use of the limited space in the car to meet the complex structural requirements of the car instrument.

Contents of the invention

The technical problem to be solved by the present invention is to provide a ring-shaped light guide plate and an automobile instrument module for the above-mentioned deficiencies in the prior art.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a ring-shaped light guide plate, which includes a base plate, a perforation is arranged in the middle of the base plate, and a protrusion extends from the edge of the perforation to the back of the base plate with the perforation as the center. , a first light diffusion part is provided on the end surface of the protrusion away from the substrate, and a second light diffusion part is provided at the bend where the substrate extends out of the protrusion; the light source enters the light guide plate from the first light diffusion part and diffuses from the second light spread to the front side of the substrate.

In the above technical solution, the protrusions are arranged continuously or alternately along the edge of the perforation.

In the above technical solution, the back surface of the substrate, the edge surface of the substrate and the peripheral surface of the protrusion are all covered with a reflective layer.

In the above technical solution, the first light diffusion part is a lower sawtooth, and the second light diffusion part is an upper sawtooth

In the above technical solution, the tooth width of the lower sawtooth is larger than the light emitting surface of the light source.

In the above technical solution, in the lower saw teeth, the tooth thicknesses are narrow inside and wide outside with the same included angle.

In the above technical solution, in the upper sawtooth, the left and right tooth profiles of the sawtooth form an angle of 90 degrees.

In the above technical solution, the substrate and the protrusion are integrally formed PC material boards.

In the above technical solution, lugs for mounting and fixing the base plate are provided on the edge of the substrate, and fixing holes are provided on the lugs.

An automobile instrument module, including a PCB board, LED, instrument pointer module and the above-mentioned ring-shaped light guide plate, the LED is installed on the PCB board, the instrument pointer module passes through the perforation of the light guide plate and the instrument panel is assembled into an instrument pointer Module, fix the light guide plate so that the lower sawtooth faces the light-emitting surface of the LED.

The beneficial effects of the present invention are:

1) In the backlight of the car instrument, the LED is placed under the light guide plate, and there is no need to reserve a 7mm LED placement space on the side of the backlight visible area, which can effectively save the shape space and achieve the ideal shape size.

2) The backlight of the car instrument is because the LED is placed under the light guide plate, the light emitted by the LED will not directly irradiate the visible area, and there is no need to consider the bright spot area of the lamp eye, so the lower sawtooth design in front of the lamp is relatively sparse to ensure that the light reaches the guide. There is better concentration in front of the light board bend, so the pitch of the lower sawtooth in front of the light is generally designed to be 0.8mm-1.4mm.

3) As the backlight of the car instrument does not directly irradiate the visible area, the light distribution of the entire visible area is relatively uniform, and the uniformity of the entire visible area reaches 80%~90%, which makes the overall display effect of the product better.

4) The number of LEDs can be selected according to the brightness requirements of the product, effectively saving costs. The structure has more flexibility, and the shape and structure can be simply designed according to product requirements.

Description of drawings

FIG. 1 is a schematic diagram of a backlight structure in the prior art;

Fig. 2 is a schematic diagram of the backlight structure of an automobile instrument in the prior art;

3 is a schematic view of the front structure of the light guide plate of the present invention;

Fig. 4 is a schematic diagram of an enlarged structure of a part X in Fig. 3;

5 is a schematic diagram of the back structure of the light guide plate of the present invention;

Fig. 6 is a schematic diagram of the enlarged structure of the part Y in Fig. 5;

Fig. 7 is a schematic cross-sectional structure diagram of the present invention (including the optical path);

Fig. 8 is a schematic diagram of the assembly structure of the automobile instrument module of the present invention.

In the figure, 1. substrate; 2. perforation; 3. protrusion; 4. upper serration; 5. lower serration; 6. visible area; 7. reflective layer; 8. tooth profile surface; 9. lug; 10. Fixing hole; 11, sawtooth; 12, LED;

13. PCB board; 14. Instrument pointer; 15. Instrument panel.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figure 3-7, a ring-shaped light guide plate includes a base plate 1, and a perforation 2 is provided in the middle of the base plate 1. The design of the perforation 2 is convenient for giving way to the pointer of the car dashboard 15. With the perforation 2 as the center, there are protrusions 3 extending from the edge of the perforation 2 to the back of the substrate 1. The protrusions 3 are arranged continuously or alternately along the edge of the perforation 2. Protrusions 3 that are perpendicular to each other, the joint between the protrusions 3 and the substrate 1 is curved, the shape of the protrusions 3 is an arc shape along the perimeter of the perforation 2, and from the root of the protrusions 3 to the end, the length of the protrusions 3 The width gradually narrows to form an arc fan. The upper sawtooth 4 is provided at the bend where the substrate 1 extends out of the protrusion 3, and the lower sawtooth 5 is provided on the end surface of the protrusion 3 away from the substrate 1; the light source is refracted and dispersed into the light guide plate from the lower sawtooth 5 for the first time, and at this time The protrusion 3 is an optical path between the lower sawtooth 5 and the upper sawtooth 4 , and performs a second refraction on the upper sawtooth 4 to diffuse to the front of the substrate 1 . The annular area of the front surface of the substrate 1 except for the through hole 2 is a visible area 6 . Serrations are also provided between the alternate projections 3 to maximize the use of light from the light source.

Wherein, the back surface of the substrate 1 , the edge surface of the substrate 1 and the peripheral surface of the protrusion 3 are all covered with a reflective layer 7 . The reflective layer 7 is a reflective film or a reflective coating, etc., which has reflective properties, so that the light entering the light guide plate will not be on the back of the substrate 1, the edge surface of the substrate 1 and the peripheral surface of the protrusion 3 due to the reflective effect. In order to increase the utilization rate of LED12 light and improve the overall brightness of the light guide plate.

Among them, in the lower sawtooth 5, the tooth width A is larger than the light-emitting surface of the light source, which can ensure the loss of the light brightness of the LED 12 as much as possible, and maximize the use of the LED 12; the tooth distance B is 0.8-1.4mm, and the tooth thickness C has the same included angle In this embodiment, the included angle D is 6 degrees, and the size of the included angle is determined according to the density of the lower serrations 5, with continuous protrusions 3 instead of alternate protrusions 3 For calculation, the width of each sawtooth in 360 degrees is 6 degrees, and there are 60 sawtooths. Then, there are 60 sawtooths arranged on the continuous protrusions 3 at equal intervals, and the alternate protrusions 3 will be missing (as in this implementation example). Due to the same included angle value, the widths at both ends of the sawtooth grooves are kept equal, which is beneficial to improve the uniformity of light diffusion. In addition, the sawtooth groove is E0.3mm deep.

Wherein, in the upper sawtooth 4, the angle between the left and right tooth profiles 8 of the sawtooth is 90 degrees; and in this embodiment, the tooth width is F8.0mm, the tooth thickness is G2.0mm, and the tooth depth is 1.45mm.

Wherein, the substrate 1 and the protrusion 3 are integrally formed PC material boards. PMMA material can also be used. PMMA has higher light transmittance, but PC material has better mechanical properties, temperature resistance and flame resistance, and optical properties in terms of uniformity of light diffusion and brightness.

Wherein, a lug 9 for mounting and fixing the base plate 1 is provided on the edge of the base plate 1 , and a fixing hole 10 is set on the lug 9 . It is mounted on the vehicle structure through this fastening hole 10 .

As shown in Figure 8, a kind of automobile meter module, comprises PCB board 13, LED12, meter pointer module and above-mentioned annular light guide plate, LED12 is installed on the PCB board 13, and meter pointer 14 modules pass through the perforation of light guide plate 2 Assemble with the instrument panel 15 to form an instrument pointer 14 module, and fix the light guide plate so that the lower sawtooth 5 faces the light-emitting surface of the LED 12.

The above embodiments are only intended to illustrate rather than limit the present invention, so all equivalent changes or modifications made according to the methods described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims (10)

1. A ring-shaped light guide plate, characterized in that: it includes a base plate, a perforation is arranged in the middle of the base plate, a protrusion is extended from the edge of the perforation to the back side of the base plate centered on the perforation, and the end face of the protrusion away from the base plate is provided with a The first light diffusion part is provided with a second light diffusion part at the bend where the protrusion extends from the substrate; the light source enters the light guide plate from the first light diffusion part, and diffuses from the second light diffusion part to the front of the substrate. 2 . The ring-shaped light guide plate according to claim 1 , wherein the protrusions are arranged continuously or alternately along the edge of the perforation. 3 . 3 . The ring-shaped light guide plate according to claim 1 , wherein the back surface of the substrate, the edge surface of the substrate and the peripheral surface of the protrusion are all covered with a reflective layer. 4 . 4 . The ring-shaped light guide plate according to claim 1 , wherein the first light diffusing portion is a lower sawtooth, and the second light diffusing portion is an upper sawtooth. 5 . The ring-shaped light guide plate according to claim 4 , wherein the tooth width of the lower sawtooth is larger than the light emitting surface of the light source. 6 . 6 . The ring-shaped light guide plate according to claim 4 , wherein, among the lower saw teeth, the tooth thicknesses are narrow inside and wide outside with the same included angle. 7 . 7 . The ring-shaped light guide plate according to claim 4 , wherein, among the upper sawtooth, the left and right tooth profiles of the sawtooth form an angle of 90 degrees. 8 . 8 . The ring-shaped light guide plate according to claim 1 , wherein the base plate and the protrusion are integrally formed of PC material. 9 . 9 . The ring-shaped light guide plate according to claim 1 , wherein a lug for mounting and fixing the base plate is provided on the edge of the substrate, and a fixing hole is provided on the lug. 10. An automobile instrument module, comprising a PCB board, an LED and an instrument pointer module, characterized in that: it also includes the annular light guide plate as claimed in any one of claims 1-9, the LED is mounted on the PCB, The instrument pointer module passes through the perforation of the light guide plate and the instrument panel is assembled into an instrument pointer module, and the light guide plate is fixed so that the lower sawtooth faces the light-emitting surface of the LED.