Backlight device

Abstract

The present invention relates to a backlight device that is applied to a vehicle display and improves screen uniformity by minimizing light interference. More specifically, it relates to a backlight device that includes variable arrangement of LED spacing, control of the driving current amount of LEDs located at both ends of an LED package, and arrangement of a stopper structure and a pad insertion part structure formed on a light guide plate to the outer edge of the screen.

Description

Technology Field

[0001] The present invention relates to a backlight device applied to a vehicle display, and in particular, to a backlight device that improves screen uniformity by minimizing light interference. Background Technology

[0002] A typical conventional side-dimmer backlight for displays is equipped with a structure for fixing a light guide panel (LGP), and is a structure in which LEDs are formed in a single-rank equal-spacing structure or in a mixed-rank and variable-pitch LED structure to obtain a luminance profile (uniformity).

[0003] FIG. 1 is a conceptual diagram showing the structure of a conventional backlight device, FIG. 2 is a conceptual diagram showing a state in which the brightness on the left and right sides of the screen is reduced relative to the center due to the structure of a conventional backlight unit, FIG. 3 is a conceptual diagram showing a state in which a gap exists between the light guide plate and the LED package due to the shape of a stopper, and FIG. 4 is a diagram showing a state in which a brightness min point occurs due to a pad located in the light guide plate pad insertion part.

[0004] Referring to Fig. 1, a conventional side-dimmering backlight unit (BLU) has a structure in which a single rank of LEDs are arranged at equal intervals.

[0005] However, such a conventional structure is one in which the light guide plate is inevitably formed in a polygonal shape due to the configuration of the stopper and pad insertion parts. As a result, as shown in Fig. 2, the central part of the screen is bright and the sides of the screen are dark, causing overall luminance non-uniformity.

[0006] In addition, due to the shape of the stopper formed on the light guide plate, a gap inevitably exists between the light guide plate and the LED package as shown in Fig. 3, which also causes a problem of brightness non-uniformity.

[0007] In addition, since a pad insertion part is formed at the upper right corner of the light guide plate and a pad is coupled thereto, a Min Point is inevitably generated structurally as shown in Fig. 4, and due to the structure of the light guide plate of the backlight unit, a problem of reduced brightness occurs due to light interference caused by the area (Corner) far from the light source (LED) and the mechanical structure.

[0008] Accordingly, there is inevitably a limit (maximum 80%) in obtaining a high brightness profile (uniformity) with only conventional single-rank LED equal spacing structures or LED rank mixing and LED spacing variable technologies. Prior art literature

[0009] (0001) Korean Registered Patent No. 10-1037507 The problem to be solved

[0010] The technical problem that the present invention aims to solve is to provide a backlight device that is applied to a vehicle display and can improve the brightness profile (uniformity) of the backlight unit to 90%.

[0011] Another technical problem that the present invention aims to solve is to provide a backlight device that applies a variable LED spacing structure to an LED package of a single luminous intensity rank in an area where brightness degradation occurs.

[0012] Another technical problem that the present invention aims to solve is to provide a backlight device having a structure in which a stopper and a light guide plate holder (pad), which are formed on the light guide plate to minimize optical interference, are placed on the screen, that is, on the outer edge of the light guide plate.

[0013] Another technical problem that the present invention aims to solve is to provide a backlight device that improves brightness uniformity by supplying a higher driving current to the LEDs located at both ends of the LED array compared to other LEDs. means of solving the problem

[0014] The backlight device of the present invention for achieving the above technical problem comprises: a rectangular light guide plate; a PCB having a plurality of LEDs arranged and combined to irradiate light toward one of the four sides of the light guide plate; and a first fixing member having one end coupled to the PCB and the other end in contact and supported toward one of the sides of the light guide plate.

[0015] In addition, the LED is characterized by having a narrower spacing between the elements as it extends from the center of the PCB toward both edges.

[0016] In addition, the driving current applied to the LED is characterized by increasing from the center toward both edges.

[0017] In addition, the plurality of the above LEDs are configured with the same luminous intensity rank, and the driving current of the LEDs located on both sides of the PCB is supplied at a level 0 to 10% higher than the driving current of the other LEDs.

[0018] In addition, the first fixed member is characterized by being a structure made of 'PC' or 'FR4'.

[0019] Additionally, the invention is characterized by further including a second fixing member that contacts and supports the light guide plate between a bottom cover that wraps around the side of the light guide plate and is coupled to the rear surface of the light guide plate, and at least one of the other three sides of the light guide plate.

[0020] In addition, the bottom cover is characterized by having a support groove formed therein into which the second fixing member is inserted and supported. Effects of the invention

[0021] The present invention described above has the following effects.

[0022] First, the light guide plate can be configured in a rectangular shape by replacing the conventional stopper structure with the first fixing member and the conventional pad structure with the second fixing member. This solves the problem of brightness non-uniformity caused by the conventional stopper structure and the pad located at the corner, and improves work efficiency by being easier to manufacture compared to the conventional polygonal light guide plate, thereby reducing manufacturing costs.

[0023] In addition, by forming the arrangement spacing of the LEDs narrowly from the center of the PCB to the edges on both sides, the dark area phenomenon on both sides as shown in Fig. 2 can be eliminated.

[0024] In addition, it is easy to manufacture an LED package by using LEDs of the same luminous intensity rank, and the dark area phenomenon on both sides can be eliminated by increasing the driving current applied to the LEDs from the center to both ends, or by increasing the driving current applied to the LEDs located at both edges compared to other LEDs to improve brightness. Brief explanation of the drawing

[0025] FIG. 1 is a conceptual diagram showing the structure of a conventional backlight device, FIG. 2 is a conceptual diagram showing a state in which the brightness on the left and right sides of the screen is reduced relative to the center due to the structure of a conventional backlight unit. FIG. 3 is a conceptual diagram showing a state in which a gap exists between a light guide plate and an LED package in the shape of a stopper. FIG. 4 is a drawing showing the state in which a brightness min point occurs due to a pad (PAD) located in the light guide plate pad insertion part. FIG. 5 is a conceptual diagram showing the arrangement of a light guide plate and an LED according to one embodiment of the backlight device of the present invention. FIG. 6 is a conceptual diagram showing an LED spacing adjustment state according to another embodiment of the present invention, FIG. 7 is a conceptual diagram showing the configuration state of the LED arrangement and the first fixing member according to an embodiment of the present invention. FIG. 8 is a drawing showing the state in which the LED is positioned at the outermost edge by omitting the stopper structure formed on the light guide plate. FIG. 9 is a conceptual diagram showing the insertion state and position of the second fixing member according to one embodiment of the present invention. Specific details for implementing the invention

[0026] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0027] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are intended only to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the terms. Where it is stated that a component is "connected," "combined," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but that another component may also be "connected," "combined," or "connected" between each component.

[0028] FIG. 5 is a conceptual diagram showing the arrangement of a light guide plate (10) and an LED (21) according to one embodiment of the backlight device of the present invention, FIG. 6 is a conceptual diagram showing the LED (21) spacing adjustment state according to another embodiment of the present invention, FIG. 7 is a conceptual diagram showing the arrangement of the LED (21) and the configuration state of the first fixing member (30) according to one embodiment of the present invention, FIG. 8 is a diagram showing the state in which the LED (21) is positioned at the outermost edge by omitting the stopper structure formed on the light guide plate (10), and FIG. 9 is a conceptual diagram showing the insertion state and position of the second fixing member (40) according to one embodiment of the present invention.

[0029] Referring to FIGS. 5 to 9, the backlight device of the present invention is described as follows.

[0030] First, since the structure of the backlight device itself is a known technology, a detailed explanation thereof is deemed likely to obscure the essence of the present invention, so a detailed explanation will be omitted.

[0031] The backlight device of the present invention comprises a light guide plate (10), a PCB (20, PCB) combined with a plurality of LEDs (21) that irradiate light onto the light guide plate (10), and a first fixing member (30) coupled to the PCB (20) and in contact with the lower periphery of the light guide plate (10).

[0032] Referring to FIG. 5, the light guide plate (10) according to the present invention is manufactured in a square shape, unlike the polygonal structure shown in FIG. 1. That is, in the past, the light guide plate (1) had to be manufactured in a polygonal shape due to the structure of the stopper (1-1) extended on both lower sides of the light guide plate (1) and the structure of the pad insertion part (1-2) formed on the upper right corner of the light guide plate (1) for inserting the pad (3). However, according to the present invention, it can be manufactured in a square shape rather than a polygonal structure. To this end, a first fixing member (30), which corresponds to the conventional stopper and will be described later, is formed on the PCB (20).

[0033] A PCB (20) can be understood as a structure combined with an LED package. The PCB (20) irradiates an LED light source to one of the four sides of the light guide plate (10). For example, the PCB (20) may be positioned at the bottom of the light guide plate (10) to irradiate an LED light source from the bottom to the top of the light guide plate (10). A plurality of LEDs (21) are arranged and combined, and all of the LEDs (21) have the same luminous intensity rank.

[0034] The LEDs (21) may be formed at equal intervals, or as shown in FIG. 5, the arrangement spacing (Pitch) may be formed to become narrower from the center of the PCB (20) toward both edges (A < B < C), or as shown in FIG. 6, the spacing of the LEDs (21) located on both sides may be formed to become narrower than that of the center (A > B). That is, when the LEDs (21) are formed at equal intervals, the driving current applied to the LEDs (21) can be controlled to increase from the center toward both edges, or the driving current can be controlled to be applied at a high level to the LEDs (21) located in the area where dark areas of the screen occur (see FIG. 2) as in the conventional method, thereby eliminating the occurrence of dark areas on both sides of the screen. Although not shown, the driving current applied to the LEDs (21) is controlled by a control unit. In addition, if the spacing of the LEDs (21) is applied differently, that is, if the spacing of the LEDs (21) is set as 'A < B < C' in FIG. 5, the driving current applied to the LEDs (21) can be applied equally or differently as described above. Also, if the spacing of the LEDs (21) is set as 'A > B' in FIG. 6, even if the driving current applied to the LEDs (21) is applied equally, the spacing of the LEDs (21) on both sides is formed more closely than the spacing of the LEDs (21) in the center, so the amount of light on both sides can be increased. Of course, it is also possible to apply the driving current differently as described above in the structure of FIG. 6. In addition, the driving current of the LEDs (21) located on both sides of the PCB (20) can be controlled to be supplied at a level 0 to 10% higher than the driving current of the other LEDs (21). That is, in the case of the LED (21) marked in dark yellow on both sides as in Fig. 5, the driving current can be variably controlled.

[0035] By controlling the spacing of the aforementioned LED (21) and the driving current applied to the LED (21), the problem of non-uniformity of brightness in the past can be resolved and the overall brightness uniformity can be improved.

[0036] Meanwhile, referring to FIG. 7, the first fixing member (30) is formed between the PCB (20), that is, between the LED (21) and the LED (21), and is made of 'polycarbonate (PC)' or 'FR4', which is widely used as an electrical insulator. Polycarbonate is the most widely used material for electrical components because it has good electrical insulation and dimensional stability, fire resistance and acid resistance, high weather resistance, and impact resistance second only to polyacetal. The lower part of the first fixing member (30) is connected to the PCB (20), and the upper part is supported in contact with the lower surface of the light guide plate (10), thereby performing the role of a stopper. Conventionally, as shown in FIG. 3, the stopper (1-1) was formed integrally on both lower sides of the light guide plate (1), so the LED (2) could not be positioned at the outermost edge due to the position of the stopper (1-1). However, when the structure according to the present invention is applied, as shown in FIG. 8, the stopper structure of the light receiving part can be removed so that the LED (21) can be positioned at the outermost edges of both sides. In addition, this can resolve the problem of reduced brightness on both sides of the screen.

[0037] The second fixing member (40), corresponding to a conventional pad, is positioned between the bottom cover (50), which is coupled to the rear surface of the light guide plate (10) while wrapping around the side of the light guide plate (10), and at least one of the other three sides of the light guide plate (10). That is, referring to FIG. 9, the second fixing member (40), which is L-shaped, is positioned at the upper right corner of the light guide plate (10) as in the conventional method, but is positioned on the perimeter of the corner of the light guide plate (10), which is configured in a square shape, without the pad insertion part formed in the light guide plate (10).

[0038] Since the second fixing member (40) is configured such that the second fixing member (40) protrudes outwardly by the thickness of the second fixing member (40) to the outside of the light guide plate (10), a support groove (51) into which the second fixing member (40) is inserted and supported can be formed in the bottom cover (50).

[0039] According to the backlight device of the present invention described above, unlike conventional methods, by applying a square-shaped light guide plate (10) structure rather than a polygonal one, and by arranging the LEDs (21) at different intervals, controlling the driving current of the LEDs (21) located at both ends of the LED package, and arranging the stopper structure and pad insertion part structure formed on the light guide plate (10) to the outer edge of the screen, the amount of light from the LEDs (21) on both sides of the screen can be increased, and by removing the stopper and pad insertion part formed on the light guide plate (10), light interference can be minimized, thereby greatly improving the uniformity of the screen compared to conventional methods.

[0040] In the foregoing, although all components constituting an embodiment of the present invention have been described as being combined or operating in combination, the present invention is not necessarily limited to such embodiments. That is, within the scope of the purpose of the present invention, all components may be selectively combined in one or more ways to operate. Furthermore, terms such as "include," "constitute," or "have" described above, unless specifically stated otherwise, mean that the relevant component may be inherent; thus, they should be interpreted as allowing for the inclusion of additional components rather than excluding other components. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Terms commonly used, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and, unless explicitly defined in the present invention, should not be interpreted in an ideal or overly formal sense.

[0041] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in this invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0042] 1 : Light guide plate 1-1 : Stopper 1-2 : Pad insertion part 2 : LED 3 : Pad 10 : Light guide plate 20 : PCB 21 : LED 30 : First fixing member 40 : Second fixing member 50 : Bottom cover 51 : Jiji Home

Claims

Claim 1 A backlight device for use in a vehicle display, comprising: a rectangular light guide plate; a PCB having a plurality of LEDs arranged and combined to irradiate light toward one of the four sides of the light guide plate; a first fixing member having one end coupled to the PCB and the other end in contact and supported on one of the sides of the light guide plate; a second fixing member having contact and supported on the light guide plate between at least one of the other three sides of the light guide plate; and a bottom cover that surrounds the sides of the light guide plate and is coupled to the rear surface of the light guide plate, and has a support groove formed in which the second fixing member is inserted and supported in a shape protruding outwardly; wherein the driving current applied to the LEDs increases from the center toward both edges. Claim 2 In claim 1, the LED is a backlight device formed such that the arrangement spacing becomes narrower from the center of the PCB toward both edges. Claim 3 delete Claim 4 A backlight device according to claim 1, wherein a plurality of the above LEDs are configured with the same luminous intensity rank, and the driving current of the LEDs located on both sides of the PCB is supplied at a level 0 to 10% higher than the driving current of the remaining other LEDs. Claim 5 A backlight device according to claim 1, wherein the first fixed member is a structure made of 'PC' or 'FR4'. Claim 6 delete Claim 7 delete

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