KR200291826Y1 - Light guide plate having 2-dimensional pattern - Google Patents

Abstract

The present invention relates to a light guide plate having an optimal two-dimensional pattern that reduces development time while obtaining uniform luminance characteristics by forming a two-dimensional light reflection structure on the light guide plate using a formula.

To this end, the present invention forms a light reflecting structure at equal intervals in the horizontal and vertical directions, and is divided by the light reflectance (R) and the light reflecting structure by the X-axis light reflecting structure formed perpendicular to the light incidence direction. A light guide plate having a two-dimensional pattern is formed by determining a light reflectance (R _n ) of an n th unit region and a pattern interval d _n of an n th unit region by a formula.

Therefore, the present invention establishes the theory of design technology to find the optimal conditions for realizing the best performance while minimizing the development period of the light guide plate pattern, and has the effect of manufacturing a light guide plate of a new model based on the result.

Description

LIGHT GUIDE PLATE HAVING 2-DIMENSIONAL PATTERN}

The present invention relates to a light guide plate having an optimal two-dimensional pattern that reduces development time while obtaining uniform luminance characteristics by forming a two-dimensional light reflection structure on the light guide plate using a formula.

In general, display devices are one of the key electronic products in the information society. Among them, a light guide plate widely used as a back light of an image display device such as a liquid crystal display device is one side of a plate made of a transparent parallel flat plate or a wedge-shaped flat plate to totally reflect the light generated from the light source so that the entire light guide plate is evenly illuminated. For example, it is in charge of the midwifery who is replacing the display device represented by cathode ray tube (CRT) with liquid crystal display (LCD).

It is the light guide plate that the backlight performance is different among manufacturers and products, and the design of the light guide plate is the most important task in the development of the backlight.

Despite the fact that the backlight is an important component to be an essential part of the LCD device, the development of new technology, which is a qualitative level, is not making much progress because of the quantitative development.

The core of the technology related to the backlight is the light guide plate design technology. Until now, Korean companies have used trial and error methods based on their own experience or depend on foreign technology.

Therefore, it takes a lot of time to develop a new product has a problem that it is difficult to realize a competitive product development because the ability to respond to the new product is released a lot.

In addition, there is a problem such as developing a pattern based on experience without a formula for formulating a pattern design for a light reflection structure formed on the light guide plate.

The present invention has been devised to solve these problems, and the present invention uses a formula to form a two-dimensional light reflection structure on a light guide plate to obtain a uniform luminance characteristic and to reduce development time. To provide a light guide plate of the purpose.

Another object of the present invention is to form a two-dimensional light reflection structure on the light guide plate by using the light reflection formula, the two-dimensional pattern that can obtain a uniform characteristic by using a standardized correction formula for the non-uniform brightness portion To provide a light guide plate.

It is still another object of the present invention to provide a light guide plate having a two-dimensional pattern in which two-dimensional light reflection structures having different depths are formed for each unit area, thereby achieving uniform luminance characteristics and shortening development time.

1 is a flow chart showing an embodiment of a light guide plate design method of a two-dimensional pattern according to the present invention,

2 is a flow chart showing another embodiment of a light guide plate design method of a two-dimensional pattern according to the present invention,

3 is a graph showing measured and calculated values of a 15-inch light guide plate having equally spaced V grooves.

FIG. 4 is a measured value of a 15-inch light guide plate in which V grooves are formed according to the X-axis pattern interval d _n .

In order to achieve the above object in one embodiment of the present invention to form a light reflecting structure of equal intervals in the horizontal and vertical direction, the light reflectance (R) by the X-axis light reflecting structure is formed perpendicular to the light incident direction and The light reflectance (R _n ) of the n-th unit region divided by the light reflecting structure and the X-axis pattern interval (d _n ) of the n-th unit region is determined by a formula to form a pattern of the light reflecting structure A light guide plate having a two-dimensional pattern is provided.

In addition, the present invention, when the light reflecting structure is formed in the same pattern, the light reflectance (R)

I _n = I _o (1-R) ^n-1 R,

I _n : light quantity in n-th unit area, I _o : total incident light quantity

The problem mentioned above is solved by the light guide plate of the two-dimensional pattern characterized by using the above.

In addition, in the present invention, when the number of unit regions is N and the amount of light emitted from each unit region is uniform, the light reflectance R _n of the n-th unit region is determined.

R _n = {1-N (1-r) ^n-1 r} / {N- (n-1)}, r: light reflectance by the Y-axis light reflecting structure

The problem mentioned above is solved as a light guide plate of the two-dimensional pattern characterized by the above-mentioned.

In addition, the present invention provides the X-axis pattern spacing d _n of the n-th unit region.

d _n = {N- (n-1)} R / {1-N (1-r) ^n-1 r} ㆍ L / N, L: length of light guide plate

The problem mentioned above is solved as a light guide plate of the two-dimensional pattern characterized by the above-mentioned.

The present invention also provides an X-axis correction pattern interval f _n for the luminance nonuniformity unit region.

f _n = R / [2 {1-N (1-r) ^n-1 r} / {N- (n-1)}-{(1 / N) + (ΔI _n / I _o )}] L / N,

ΔI _n = increased amount of light in the nth unit area

The above-mentioned problem is solved by the light-guide plate of the two-dimensional pattern which determined and formed the pattern of the said light reflection structure.

In addition, the present invention, the light reflection structure is a two-dimensional, characterized in that formed on the back of the light guide plate using one of light scattering printing method, V groove method, U groove method, orthogonal time signal method, amorphous time signal method, OPI method The above-mentioned problem is solved as a light guide plate of a pattern.

The present invention also solves the above-described problems as a light guide plate having a two-dimensional pattern, wherein the light guide plate is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method.

In order to achieve the above object, in another embodiment of the present invention, a light reflection structure having different depths is formed in the horizontal and vertical directions while maintaining the same spacing, and is formed by the X-axis light reflection structure formed perpendicular to the light incidence direction. After measuring the light reflectance (R) and determining the light reflectance (R _n ) of the n-th unit region, the X-axis pattern depth (h _n ) of the n-th unit region corresponding to the light reflectance (R _n ) is determined. A light guide plate having a two-dimensional pattern is formed by determining the pattern of the light reflection structure by determining from the reflectance (R).

In addition, the present invention, when the number of the unit region is N and the amount of light emitted from each unit region is uniform, the light reflectance (R _n ) of the n-th unit region is

R _n = {1-N (1-r) ^n-1 r} / {N- (n-1)}

r: light reflectance by the Y-axis light reflecting structure

The problem mentioned above is solved as a light guide plate of the two-dimensional pattern characterized by the above-mentioned.

In addition, the present invention is a light guide plate of a two-dimensional pattern, characterized in that the pattern of the light reflection structure is formed by determining the X-axis correction pattern depth (j _n ) for the luminance nonuniformity unit region from the light reflectivity (R). The above problem is solved.

The present invention also provides a light reflectance (R _s ) for the luminance nonuniformity unit region.

I _n = I _o (1-R _s ) ^n-1 R _s ,

I _n : light quantity in n-th unit area, I _o : total incident light quantity

After determining by using, the X-axis correction pattern depth (j _n ) for the luminance nonuniformity unit area corresponding to the difference between the light reflectance (R _n ) of the _nth unit region and the light reflectance (R _s ) for the luminance nonuniformity unit region The problem described above is solved by the light guide plate of the two-dimensional pattern which was determined from the light reflectivity R by the said X-axis light reflection structure.

In addition, the present invention solves the above-described problems as a light guide plate having a two-dimensional pattern, wherein the light reflection structure is formed on the rear surface of the light guide plate using a V groove method or a U groove method.

The present invention also solves the above-described problems as a light guide plate having a two-dimensional pattern, wherein the light guide plate is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method.

The objects, features and advantages of the present invention will be more readily understood by reference to the accompanying drawings and the following detailed description.

The present invention proposes a light guide plate having an optimal two-dimensional pattern which achieves uniform luminance characteristics and shortens development time by forming a two-dimensional light reflection structure on the light guide plate using a formulated formula as a preferred embodiment.

A design method for quickly obtaining a two-dimensional light guide plate pattern having uniform luminance characteristics will be described with reference to FIGS. 1 to 3.

1 is a flowchart illustrating an embodiment of a method of designing a light guide plate having a two-dimensional pattern according to the present invention.

First, the standard of the light guide plate to be manufactured is selected. The design of the light guide plate pattern using the present invention can be applied without limitation to the size of the light guide plate, that is, the size of the width or length.

When the size of the light guide plate is selected, the position where the light source is to be installed is selected from four corners of the light guide plate. The light incident from the selected light source is totally reflected into the light guide plate and is reflected by the light reflection structure on the rear surface of the light guide plate to have a function as a light guide plate for a backlight.

Next, a light reflection structure having equal intervals in the horizontal and vertical directions on the light guide plate (S100). In this case, the area divided by the light reflection structure is defined as a unit area, and the light reflection structure is preferably the same pattern for each unit area. The width of each unit region is constant in the horizontal and vertical directions, respectively, and the width of the unit region is preferably a value capable of forming at least one light reflection structure having a minimum reflectance.

The light reflection structure is formed on the rear surface of the light guide plate using one of light scattering printing method, V groove method, U groove method, orthopedic signal method, amorphous time signal method, and OPI method.

The light scattering printing method is to form a material having high light reflection efficiency on the light guide plate by printing method, and the groove method is to engrave V, U, square or circular grooves directly on the light guide plate or to form the mold.

Therefore, in the light scattering printing method, the printing material having the same area is formed, and the V groove method, the U groove method, the standard time signal method, the amorphous time signal method, and the OPI method are formed with the same depth.

When there are N + 1 light reflecting structures formed on the light guide plate, N unit regions are uniformly formed from one end face to which the light source is incident to the other end face of the light guide plate.

After the light reflection structure is formed in step S100, the light reflection structure is assembled in a backlight state to measure the light amount I _n of the n-th unit region (S110). And determines the optical reflectivity (R _n) of the light reflection factor (R) and n-th unit areas according to the light incidence direction and the X-axis the reflecting structure is formed perpendicularly (S120).

When the amount of light I _n measured at step S110 is applied to Equation 1 to solve the system of simultaneous equations, the light reflectance R due to the light reflection structure may be determined.

,

I _o : Total incident light

For example, when the light reflecting structure using the light scattering printing method is formed on the light guide plate, Equation 1 may determine the light reflectance according to the size of the printed light reflector area.

In addition, when the V groove or another type of light reflector is processed and formed directly on the light guide plate, or the light reflector is engraved on the mold to be formed on the light guide plate, the light reflectance according to the processing degree of the light reflector can be determined.

If the measured value of the total incident light is accurate, the light reflectance R by the light reflection structure may be determined by applying the light amount I _n measured in step S110 to Equation 1.

Table 1 shows the light quantity measured values and calculated values of a 15-inch light guide plate having equally spaced V grooves.

Unit area (N) (Unit: mm) Measured value (I _n ) (unit: cd / m ² ) Calculated Value (I _n ) (Unit: cd / m ² ) Measuring conditions 10 681 828 Light guide plate thickness 4.5mm Applied voltage 9.1V Tube current 244mm Measuring distance 70cm 20 692 742 30 654 665 40 605 595 50 533 533 60 494 477 70 433 428 80 391 383 90 342 343 100 294 307 110 269 275 120 242 246 130 219 221 140 195 198 150 180 177 160 158 158 170 145 142 180 132 127 190 124 114 200 118 102

In Table 1, the R value of the 15-inch light guide plate was 0.0109668, and the total incident light amount was 83428.5354 (cd / m ² ), which was measured by attaching a white reflective film and a diffusion film.

The graph for Table 1 is shown in FIG. 3. Since the amount of light derived from each unit region is the amount of light derived per unit area, this may be referred to as luminance at the light guide plate surface. Therefore, the measured value is represented by the luminance value and the unit uses cd / m ² .

Comparing Table 1 with FIG. 3, the amount of light for each unit region is high at the incidence end of the light guide plate, and the light quantity decreases as the light is moved away from the incidence end of the light guide plate. This is because the light reflection structures formed in each unit region are all the same structure, and the light reflectance R due to the light reflection structure is constant.

Since the LGP is divided into N unit areas, the amount of light emitted from each unit area must be uniform to obtain uniform optical characteristics on the surface of the LGP. When the amount of light emitted from each unit region is uniform, the light reflectance R _n of the nth unit region is determined by Equation 2 below.

,

r: light reflectance by the Y-axis light reflecting structure

When the amount of light emitted from each unit region satisfies I _o / N, a light guide plate having an ideal shape can be manufactured.

When the light reflection structure of the light guide plate is a light scattering printing method, the printing area is determined as much as the light reflectance R _n in each unit region. In this case, the printed pattern may be a printed pattern having a smaller area than the end portion of the light guide plate through which the printing area of the light incident side is directed.

When the light reflection structure of the light guide plate is a V groove having a constant depth, the light reflectance R _n of each unit region is determined differently by adjusting the interval of the V groove.

The X-axis pattern interval d _n of the n-th unit region is determined using the light reflectance R by the X-axis light reflecting structure determined in step S120 and the light reflectance R _n of the n-th unit region (S130). . When the length of the light guide plate is L, the X-axis pattern interval d _n of the n-th unit region is determined by Equation 3 below.

The light guide plate prototype is manufactured by forming a light reflection structure on the light guide plate according to the X-axis pattern interval d _n determined in step S130 (S135). At this time, the light guide plate prototype is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method.

Table 2 shows measured values of the 15-inch light guide plate having V grooves according to the X-axis pattern interval d _n , and a graph of Table 2 is shown in FIG. 4. Table 2 shows the values obtained by attaching three diffusion films on a light guide plate of 4 mm.

Unit area (N) (Unit: mm) Measured value (I _n ) (unit: cd / m ² ) Unit area (N) (Unit: mm) Measured value (I _n ) (unit: cd / m ² ) 10 681 110 681 20 692 120 692 30 654 130 654 40 605 140 605 50 533 150 533 60 494 160 494 70 433 170 433 80 391 180 391 90 342 190 342 100 294 200 294 Luminance uniformity 99%

The measurement results of the light guide plate prototype show an error in the inlet and the end of the light guide plate to which the light source is incident. This causes the error by assuming that light is only a one-dimensional vector incident perpendicularly to the incident surface.

Incident light has a spectral distribution characteristic close to an elliptic state. Therefore, the incident light proceeds radially, and in particular, it is radiated within the total reflection angle at the incidence portion and is not totally reflected inside the light guide plate, but is directly directed to the light guide plate surface. The emitted light is observed high in the left part of the graph.

In the end portion of the light guide plate, since the light propagated into the light guide plate is reflected at the end of the light guide plate, the light proceeds back to the inside of the light guide plate.

The light is reflected back at the end of the light guide plate because light is reflected due to a difference in refractive index when light travels from the dense medium to the medium.

In order to correct the portion where the luminance increases at both ends, the present invention measures the amount of light ΔI _n increased in the nth unit region (S140), and the X-axis correction pattern interval f _n for the luminance nonuniformity unit region. Determine (S145).

The correction pattern interval f _n of the n-th unit region is determined by Equation 4.

The light guide plate is manufactured according to the interval set in step S100 and the X-axis pattern interval d _n determined in step S130 and the X-axis correction pattern interval f _n determined using Equation 4 (S150).

In this case, as in step S135, a light guide plate is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method.

Although the reflectance can be obtained manually by using the light guide plate pattern design formula provided by the present invention, another object of the present invention is to use a minimum time for pattern design. Therefore, it is preferable to implement and use the above-described design formula as a light guide plate pattern design program for calculating the reflectance for each unit region.

2 is a flowchart illustrating another embodiment of a light guide plate design method of a two-dimensional pattern according to the present invention. In the embodiment of FIG. 2, the light reflection structure is formed in the horizontal and vertical directions while maintaining the same spacing on the light guide plate, but its depth is different for each unit region.

First, as described above, the position of the light source is selected from the standard of the light guide plate to be manufactured and the four corners of the light guide plate.

Then, while maintaining the same distance to the light guide plate to form a light reflection structure of different depths in the horizontal and vertical directions (S200). At this time, the light reflection structure is formed on the rear surface of the light guide plate by using the V groove method or the U groove method, and preferably have the same pattern.

The width of each unit region is constant in the horizontal and vertical directions, respectively, and the width of the unit region is preferably a value capable of forming at least one light reflection structure having a minimum reflectance.

When there are N + 1 light reflecting structures formed on the light guide plate, N unit regions are uniformly formed from one end face to which the light source is incident to the other end face of the light guide plate.

Next, the light reflectance R according to the depth of the X-axis light reflecting structure formed perpendicular to the light incidence direction is measured (S210), and the light reflectance R _n of the nth unit area divided by the light reflecting structure is determined. Determine (S220).

When the number of unit regions is N and the amount of light emitted from each unit region is uniform, the light reflectance R _n of the n-th unit region is determined by Equation 2 below.

Next, the X-axis pattern depth h _n of the n-th unit region corresponding to the light reflectance R _n is determined from the light reflectance R measured in step S210 (S230), and the X-axis pattern depth h _n The light reflection structure is formed on the light guide plate (S235) to manufacture a light guide plate prototype.

At this time, the light guide plate prototype is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method.

Since the brightness increases as described above at the inlet and end of the light guide plate prototype, this part should be corrected.

To this end, the light amount I _n of the n th unit region is measured (S240), and the light reflectance R _s of the luminance nonuniformity unit region of the light guide plate is determined using Equation 5 (S245). Solving Equation 5 by the simultaneous equation, it is possible to determine the light reflectance (R _s ) for the luminance nonuniformity unit region.

,

I _o : Total incident light

When the light reflectance (R _s ) is determined in step S245, a difference from the light reflectance (R _n ) determined in step S220 may be obtained.

Therefore, the X-axis correction pattern depth j _n for the luminance nonuniformity unit area corresponding to the difference between the light reflectivity R _{n of the nth} unit area and the light reflectance Rs _{s for} the luminance nonuniformity unit area is determined by the light reflectance ( It determines from R) (S250). The light guide plate is manufactured according to the interval set in step S200, the X-axis pattern depth h _n determined in step S230, and the X-axis correction pattern depth j _n determined in step S250 (S260).

In this case, as in step S235, a light guide plate is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention defined in the appended claims.

As described above, the present invention can design a light guide plate that greatly influences the performance of a backlight without using experience, and design an optimal two-dimensional pattern with uniform luminance characteristics efficiently, precisely and quickly by using a formula. It can be effective.

In the case of a 15-inch light guide plate designed using the formula of the present invention, it was possible to manufacture a backlight having a luminance uniformity characteristic of 99%.

In addition, a light guide plate having uniform characteristics can be manufactured by using a standardized correction formula for a portion having uneven luminance.

In addition, when manufacturing a light guide plate having a two-dimensional light reflection structure having a different depth for each unit region by using the theory established in the present invention, it is possible to develop a light guide plate having a uniform luminance characteristics in a shorter time than before.

In addition, when the light guide plate of the new model is developed, it can be efficiently performed, and the design value of the optimum condition can be obtained.

Claims (13)

The light reflectance (R) of the X-axis light reflecting structure which is formed at equal intervals in the horizontal and vertical directions, and is formed perpendicular to the light incidence direction, and the nth unit region divided by the light reflecting structure. A light guide plate having a two-dimensional pattern, wherein the light reflectance (R _n ) and the X-axis pattern interval (d _n ) of the n-th unit region are determined by a formula to form a pattern of the light reflection structure. The method of claim 1, wherein the light reflectance (R) is When the light reflection structure is formed in the same pattern, I _n = I _o (1-R) ^n-1 R, I _n : light quantity in n-th unit area, I _o : total incident light quantity The light guide plate of the 2D pattern characterized by the above-mentioned. The light reflectance (R _n ) of the n-th unit area is equal to the number of unit areas and the amount of light emitted from each unit area is uniform. R _n = {1-N (1-r) ^n-1 r} / {N- (n-1)}, r: light reflectance by the Y-axis light reflecting structure The light guide plate of the 2D pattern characterized by the above-mentioned. The method of claim 3, wherein the X-axis pattern interval d _n of the n-th unit area is d _n = {N- (n-1)} R / {1-N (1-r) ^n-1 r} ㆍ L / N, L: length of light guide plate The light guide plate of the 2D pattern characterized by the above-mentioned. The method of claim 1, wherein the X-axis correction pattern interval f _n for the luminance nonuniformity unit area is f _n = R / [2 {1-N (1-r) ^n-1 r} / {N- (n-1)}-{(1 / N) + (ΔI _n / I _o )}] L / N, ΔI _n = increased amount of light in the nth unit area A light guide plate having a two-dimensional pattern, characterized in that the pattern of the light reflection structure is formed by the determination. The light reflecting structure of any one of claims 1 to 5, wherein A light guide plate of a two-dimensional pattern, characterized in that formed on the back of the light guide plate using one of light scattering printing method, V groove method, U groove method, orthogonal time signal method, amorphous time signal method, OPI method. The light guide plate according to any one of claims 1 to 5, wherein the light guide plate A light guide plate having a two-dimensional pattern, which is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method. While maintaining the same distance, the light reflecting structures having different depths are formed in the horizontal and vertical directions to measure the light reflectance (R) by the X-axis light reflecting structures formed perpendicular to the light incidence direction, and the after determining the optical reflectivity (R _n), and determining from the optical reflectivity (R) a pattern of the light reflecting structure the X axis the pattern depth (h _n) of the n-th unit areas corresponding to the light reflection factor (R _n) A light guide plate having a two-dimensional pattern, which is formed. The method of claim 8, wherein when the number of unit regions is N and the amount of light emitted from each unit region is uniform, the light reflectance (R _n ) of the n-th unit region is R _n = {1-N (1-r) ^n-1 r} / {N- (n-1)} r: light reflectance by the Y-axis light reflecting structure The light guide plate of the 2D pattern characterized by the above-mentioned. The light guide plate according to claim 8, wherein the light reflection structure pattern is formed by determining the X-axis correction pattern depth (j _n ) for the luminance nonuniformity unit region from the light reflectivity (R). The method of claim 10, wherein the light reflectance (R _s ) for the luminance nonuniformity unit area I _n = I _o (1-R _s ) ^n-1 R _s , I _n : light quantity in n-th unit area, I _o : total incident light quantity After determining by using, the X-axis correction pattern depth (j _n ) for the luminance nonuniformity unit area corresponding to the difference between the light reflectance (R _n ) of the _nth unit region and the light reflectance (R _s ) for the luminance nonuniformity unit region The light guide plate of the two-dimensional pattern characterized by determining from the light reflectivity (R) by the said X-axis light reflection structure. The light reflecting structure of any one of claims 8 to 11, wherein A light guide plate having a two-dimensional pattern, characterized in that formed on the back of the light guide plate using a V groove method or a U groove method. The light guide plate of claim 8, wherein the light guide plate is A light guide plate having a two-dimensional pattern, which is manufactured using one of a mold manufacturing method, a printing method, a V cutting method, and a U cutting method.