JPH09113907A - Light transmission plate and surface type illuminating body using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain not only a narrow frame state by using a short light source but also a screen having high luminance and high uniformity of illuminance, which are contrary to each other, and to make a liquid crystal screen compact. SOLUTION: As for this light transmission plate 1; its front surface is a light emitting surface S2, its rear surface is a reflection surface S3, its one-side end face is a light entering end face S1, and its other side surfaces are reflection side end faces S4 and S5. On the plate 1, light entering from a light source 2 disposed along the end face S1 is scattered and the light is emitted from the light emitting surface S2. In such a case, a light scattering means L for strengthening the light scattering in a direction parallel to the light emitting surface S2 out of the light entering internally from the end face S1 is formed on the end face S1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge light type light guide plate and an improvement of a surface illumination body using the light guide plate.

[0002]

2. Description of the Related Art This type of light guide plate (1) is a light emitting surface (S2) with a large area that scatters light from a cold cathode tube which is a light source (2) arranged along a light incident end surface (S1). It is widely used as a surface light source of a planar lighting body (B) that uniformly illuminates a wide display surface, and is widely used as a backlight device for liquid crystal display devices in recent years as well as for displaying advertising lights, etc. It is used.

Recently, in order to narrow the frame of the liquid crystal display device, the cold cathode tube (2) is shortened to reduce the total length of the light guide plate (1).
The state where the electrode part (2a) of the cold cathode tube (2) is inserted into one end or both ends of (S1) is designed. Therefore, no matter how the density of white printed dots (6) or grain dots (6a) on the reflective surface (S3) is adjusted, one end of the light incident end surface (S1) on the electrode part (2a) side or both ends as shown in FIG. There was a problem that the vicinity became dark and it was not possible to achieve the required high uniformity of the light output screen. In FIG. 20, the dark portion in the vicinity of both ends of the light incident end surface (S1) is indicated by (2b). Therefore, when the light path is changed by directing the ridges of the two directional sheets (not shown in FIGS. 19 and 20) downward to make the light brighter, the light guide plate (1) becomes a mirror and the cold cathode tubes (2 ), The white printed dots (6) and the embossed dots (6a) can be seen through, including the imprint (2c). (FIG. 20) Then, in order to improve this, a strong diffusion sheet (not shown in FIGS. 19 and 20) was arranged on the directional sheet, but this resulted in a large decrease in average luminance, and thus far. As a result, the efforts to increase the brightness of the result were attributed to blisters.

[0004]

However, on the user side, in order to achieve the compactness of the liquid crystal screen, both the narrow frame and the high-brightness / high-uniformity screen are required at the same time. A technical problem to be solved is to provide a light guide plate having a high brightness, high uniformity, and a narrow frame screen without a dark portion in the vicinity of both ends of the light end face, and a planar illumination body using the light guide plate.

[0005]

<Claim 1> is a first embodiment (1A) of FIG. 1 of a light guide plate (1) according to the present invention, "the surface is a light emitting surface (S2), The back surface is a reflection surface (S3), one end surface is a light incident end surface (S1), the other side surface is a reflection side end surface (S4) (S5), the light incident end surface (S1) In the light guide plate (1) that scatters the light entering from the light source (2) arranged along the light exit surface (S3) and enters the inside from the light entering end surface (S1). Among the light, a light scattering means (L) for enhancing light scattering in a direction parallel to the light exit surface (S2) is formed on the light entrance end surface (S1).

In this case, the light scattering means (L) is formed only on the light incident end surface (S1), and the light exit surface (S2), the reflection surface (S3), and the reflection side end surfaces (S4) (S5) are flat. The surface. The light scattering means (L) formed on the light incident end surface (S1) of the light guide plate (1) is the light incident end surface (S1).
Compared with the case where is flat, it has a function of positively scattering the light incident on the light incident end surface (S1) in the direction parallel to the light exit surface (S2) (hereinafter referred to as horizontal scattering function). For example, the vertical ridges (8a) and the concave ridges (8'a) as will be described later will be referred to as `` the ridges forming the light scattering means (L) are (8a) and the concave ridges (8'a). Convex stripes (8) or concave stripes formed on the light emitting surface (S2) or reflecting surface (S3)
Distinguish from (8 '). The same applies to the light scattering means (L) and the light exit surface
(S2) and the reflective surface (S3) that have the same shape or function are related to the light scattering means (L) (...
A) is added to distinguish the two. ”Concave or convex grain dots
(6a b) “The grain dots forming the light scattering means (L) are defined as (6a b) on the light emitting surface (S2) and the reflecting surface (S3).
Distinguish from a). ], The case where the concave light incident end surface (S1) is formed (the same applies hereinafter). According to this, the light incident end face (S
1) Part of the light that enters the light guide plate is reflected either directly or afterwards
The light is emitted from the light output surface (S3) of (1), but the rest and its reflected light are refracted or totally reflected and scattered more in the direction parallel to the light output surface (S2), and the reflection side end surface (S4) (S5), etc. At a wide angle, the light is passed back and forth through the entire light guide plate (1) many times to make the brightness of the light guide plate (1) uniform. As a result, even if a light source (2) shorter than the width of the light incident end surface (S1) is used, the dark areas (2b) at both ends of the light incident end surface (S1) can be eliminated, resulting in high brightness and high uniformity.
It was possible to use it as a light guide plate (1A) for a narrow frame screen. Note that white dot printing (6) to grain dots (6a) are usually formed on at least one of the light emitting surface (S2) and the reflecting surface (S3).

<Claim 2> is a light guide plate (1) according to the present invention.
In the second embodiment (1B) “FIG. 2” and the third embodiment (1C) “FIG. 3” of
"The surface is the light emitting surface (S2) and the back surface is the reflecting surface (S3)
The one end face is the light incident end face (S1), the other side end face is the reflection side end face (S4) (S5), the light incident end face (S
In the light guide plate (1) that scatters the light entering from the light source (2) arranged along 1) and emits the light from the light exit surface,
Of the light entering inside from the light incident end surface (S1), the light scattering means (L) that enhances the scattering of light in the direction parallel to the light exit surface (S2) is provided at the light incident end surface (S1) and at least one reflection. It is formed on the side end face (S4) (S5) ''. In this case, the light incident end face (S
1) and at least one of the reflection side end faces (S4) (S5) has a light scattering means.
(L) is formed, and the rest of the light output surface (S2), the reflection surface (S3), and the reflection side end surfaces (S4) (S5) are flat surfaces. According to this, in addition to the first embodiment (1A), the reflection side end surface (S4) or / and
Even in (S5), the light scattering effect in the direction parallel to the light exit surface (S2) (hereinafter,
This is simply called the horizontal scattering effect. ) Is obtained, and higher uniformity is obtained. In particular, when the light scattering means (L) is formed on all the reflection side end faces (S4) (S5), the light passing through the inside of the light guide plate (1) is parallel to the light emission face (S2). The maximum degree of scatter in all directions (hereinafter referred to as horizontal scatter) is achieved to achieve the highest degree of uniformity. As a result, not only the dark area (2b) is eliminated, but also the light source.
The reflection (2c) in (2) will be completely eliminated.
Incidentally, at least one of the light emitting surface (S2) and the reflecting surface (S3), usually white dot printing (6) to grain dots (6a)
Is formed.

<Claim 3> is a light guide plate (1) according to the present invention.
In the fourth embodiment (1D) "FIG. 4", "the front surface is the light output surface (S2), the back surface is the reflection surface (S3), and one side end surface thereof is the light input end surface (S1)." The other side end surface is the reflection side end surface (S4) (S5), and the light source is arranged along the light incident end surface (S1).
In the light guide plate (1) that scatters the light entering from (2) and emits the light from the light exiting surface (S2), among the light entering inside from the light entering end surface (S1), the light exiting surface (S2 ) Is formed on the light incident end surface (S1) to enhance the scattering of light in the direction parallel to the light exit surface (S2) or the reflection surface (S3) located on the opposite side or the light exit surface. Both (S2) and the reflecting surface (S3), the edge line (E1) between the light emitting surface (S2) and the light incident end surface (S1) or the edge line between the reflecting surface (S3) and the light incident end surface (S1) ( E2) so as to be orthogonal or inclined with respect to ridge (8) or groove (8 ') or ridge (8) and groove (8')
Alternately and light emitting surface (S2) or reflecting surface (S3) or light emitting surface (S2)
It is formed on both the reflection surface and the reflection surface (S3).

In this case, the light scattering means is provided only on the light incident end surface (S1).
(L) is formed, and the light-scattering means (L) is not formed on the reflection-side end surfaces (S4) and (S5), which are flat surfaces. Then, the ridge (8) or the ridge (8 ′) is formed on at least one of the light emitting surface and the reflecting surface (S3). According to this,
As described in claim 1, the light incident on the light incident end surface (S1) is positively scattered by the light scattering means (L) in a direction parallel to the light emitting surface (S2). (S2) and reflective surface (S
The ridges (8) or recesses (8 ') formed in 3) have the function of guiding the light introduced into the light guide plate (1) to the back of the light guide plate (1) [the ridges (8) or the recesses]. The light introduced into the strip (8 ') repeats total reflection and is convex.
(8) Or go to the back of the groove (8 '). ],
The horizontal light diffusion effect and the light guiding effect act synergistically to realize a highly uniform screen. That is, the horizontal light diffusion effect is the light guide plate.
The dark part (2b) that tends to occur at both ends of the light incident end face (S1) of (1) is eliminated, and the light guiding effect guides light to the inner part of the light guide plate (1), and the light incident end face (S1) side And the reflection side end face on the opposite side (S5)
This is because it acts to reduce the luminance distribution of and. Here, the edge line refers to a line of intersection between adjacent surfaces, and in the case where the faces have irregularities, the line of intersection of average virtual planes connecting the tips of the convexes (for example, the virtual line in FIGS. 9 to 11). Line).

Further, the ridges (8) or the ridges (8 ') formed on the light emitting surface (S2) and the reflecting surface (S3) have a light collecting function as well as the light guiding function. That is, in the case of the ridge (8), the emitted light is closer to the condensing side << = the luminous flux emitted from the light emitting surface (S2) approaches the direction closer to the light emitting surface (S2) in the vertical direction >>. Go to
In other words, the ridge (8) emits the light output angle distribution in the direction parallel to the light incident end surface (S1) among the light emitted from the light output surface (S2) after being reflected and scattered in the light guide plate (1). It has a function of collecting light in a direction perpendicular to the surface (S2).

Also in the case of the concave strip (8 '), the light emitted from the concave strip (8') is changed to the reflected light which reflects on the inner surface of the concave strip (8 '), so that it also has a specific divergence angle as a whole. It becomes Idemitsu. If this point is explained in detail, as shown in FIG. 17 (b), the light guide plate (1)
Is an acrylic resin plate, for example, and has a semicircular cross section
When the light is emitted from (8 '), a part (a) of the innumerable luminous flux heading to the concave line (8') in the light guide plate (1) is refracted at the inner peripheral surface of the concave line (8 '). This light (b) once appears in the air layer and is recessed (8 ')
It is reflected at the point 0 on the inner surface of the
Light will be emitted by grabbing the edge of (8 '). If there is one concave line (8'), light (ha) (ha ') << light (ha') is concave line (8 ') Light is emitted symmetrically with respect to the center line (CL) of. The light will be emitted within the range (= output angle distribution) indicated by the box, and as a result, it will be condensed.

As described above, since the ridges (8) or the ridges (8 ') formed on the light emitting surface (S2) and the reflecting surface (S3) have a light guiding function and a light collecting function, The ridges (8) or the ridges (8 ') have almost the same function as the conventional directional sheet (3a1) installed so that the groove rows are perpendicular to the light incident end surface (S1). Therefore, this directional sheet (3a1) can be omitted, and the other directional sheet (3a2) ‘groove row (1
2) is installed in a direction substantially parallel to the light incident end surface (S1) or slightly inclined ”. This allows
Two directional sheets (3a1) (3a2) that were needed before
The cost can be reduced because it can be reduced to one of (3a2). In addition, when the constituent surface of the convex strip (8) or the concave strip (8 ') of the light emitting surface (S2) is mirror-finished, the light on the surface of the convex strip (8) or the concave strip (8') is Scattering is suppressed, and the light collecting property is improved. In addition, the normal white dot printing (6) to grain dots (6a) is provided on at least one of the light emitting surface (S2) and the reflecting surface (S3) on which the convex stripes (8) or the concave stripes (8 ') are not formed. It is formed.

<Claim 4> is a light guide plate (1) according to the present invention.
In the fifth embodiment (1E) of "Fig. 5", "the front surface is the light exit surface (S2), the back surface is the reflection surface (S3), and one side end surface thereof is the light entrance end surface (S1). The other side end surface is the reflection side end surface (S4) (S5), and the light source is arranged along the light incident end surface (S1).
In the light guide plate (1) that scatters the light entering from (2) and emits the light from the light exiting surface (S2), among the light entering inside from the light entering end surface (S1), the light exiting surface (S2 ) Is formed on the light incident end face (S1) and at least one reflection side end face (S4) or / and (S5) to enhance the scattering of light in a direction parallel to (), and the light exit face (S2) Or, on both the reflecting surface (S3) or the light emitting surface (S2) and the reflecting surface (S3) located on the opposite side, the light emitting surface (S2) and the light incident end surface.
Edge line (E1) with (S1) or reflecting surface (S3) and light incident end surface
The ridges (8) or the ridges (8 ') or the ridges (8) and the ridges (8') are alternately emitted so as to be orthogonal or inclined to the edge line (E2) with (S1). It is formed on the surface (S2) or the reflecting surface (S3) or both the light emitting surface (S2) and the reflecting surface (S3) ”.

In this case, the light scattering means (L) causes the light incident end face (S
1) and the reflection side end surface (S4) (S5) is formed on at least one of the reflection side end surface (S) without the light scattering means (L) formed.
4) (S5) is a flat surface. And the light emitting surface (S2) and the reflecting surface (S3)
A ridge (8) or a ridge (8 ') is formed on at least one of them. According to this, as described in claim 2, the light incident on the light incident end surface (S1) is strongly strong not only at the light incident end surface (S1) but also at the reflection side end surface (S4) and / or (S5). A light source that is scattered in the horizontal direction and further has a light guiding effect and a light collecting effect due to the convex stripes (8) or concave stripes (8 ') formed on the light emitting surface (S2) and the reflecting surface (S3). Achieve the best uniform screen without reflection in (2). Also in this case, the ridge
Ordinary white dot printing (6) to grain dots (6a) are formed on either (8) or the light emitting surface (S2) and the reflecting surface (S3) where the concave streak (8 ') is not formed.

<Claim 5> is the first specific example of the light scattering means (L) (FIGS. 1 to 5 and 9 to 11), and the “light scattering means (L) according to claims 1 to 4 Edge line (E1) (E3) of surface (S2)
Also, the ridges (8a) or the ridges (8'a) formed so as to be orthogonal or inclined to any of (E5) or the ridges (8a) and the ridges (8a) formed alternately According to this, the convex stripes (8a) and the concave stripes that are the light scattering means (L).
(8 ′) strongly scatters in the direction parallel to the light exit surface (S2), which contributes to improving the uniformity of the screen and preventing the light source (2) from being reflected.

<Claim 6> is the second specific example of the light scattering means (L) (see FIGS. 7 and 12). The light scattering means (L) according to any one of claims 1 to 4 is concave. Or, it is a convex wrinkle dot (6a a) '', and when the wrinkle dot (6a a) is concave, the light that has entered the wrinkle dot (6a a) collides with its slope and its Part of the light enters the light guide plate (1) from the collision part, and the remaining part is reflected at the collision part and advances to the back of the embossed dot (6a), and enters the light guide plate (1) from the back of the embossed dot (6a). .
This light has a strong directivity, and most of the light diffuses in the light guide plate (1), but travels toward the opposite reflection-side end surface (S5) and is reflected by the reflection-side end surface (S5). The part with this reflected light is reflected by the reflection surface (S3) or directly on the light emission surface (S3).
Light is emitted from 2), and the remaining portion is directed to the light incident end surface (S1) and further scattered by the grain dots (6a) on the light incident end surface (S1). The other part of the remaining portion is reflected by the reflection side end surface (S4). Then, the reflected light repeatedly passes through the light guide plate (1) to eliminate dark portions (2b) that are likely to occur at both ends of the light incident end surface (S1) of the light guide plate (1), thereby improving the uniformity of the screen.

When the embossed dot (6a) is convex, the light colliding with the slope of the embossed dot (6a) is partially reflected at the collision part and travels in the direction of the light incident end face (S1) to enter the light. Enter the inside from the end face (S1). The remaining part is refracted at the collision part and enters the light guide plate (1). When the embossed dots (6a) are adjacent to each other, the embossed dots (6a) adjoin to each other and proceed while repeating collisions, and finally enter the inside from the light incident end surface (S1). In this way, a part of the light that has entered the light guide plate (1) is emitted, and the remaining part repeatedly passes through the light guide plate (1) by repeating scattering and reflection as described above. Increase the uniformity of (1).

<Claim 7> is the third specific example of the light scattering means (L) (see FIGS. 8 and 13), and “any one of the light scattering means (L) according to claim 1 is a light emitting surface. Edge line (E1) of (S2)
(E3) or (E5) the surface in the direction along is formed by a concave surface, '' in which case the light is directed to the light exit surface (S2) in accordance with the concave light incident end surface (S1). Since the light is scattered more strongly in the parallel direction, more of the incident light is reflected by the reflection side end surface (S4) adjacent to the concave light incident end surface (S1) and the reflected light is inside the light guide plate (1). Will be repeatedly scattered. As a result, the same effects as those of the convex strip (8a), the concave strip (8'a), and the concave / convex grain dot (6a) can be obtained.

<Claim 8> is a ridge which is a light scattering means (L).
Regarding the pitch of (8a) or concave strip (8'a), "in the light guide plate (1) according to any one of claims 3 to 5, the convex strip (8a) or the concave strip (8 ').
B) or the pitch of the convex stripes (8a) and the concave stripes (8'a) provided alternately is 10 to 1,000 μm. ”The coarser the pitch, the lower the manufacturing cost. I can do things.

<Claim 9> relates to the first embodiment in the shape of the convex stripes (8a) (8) or the concave stripes (8'a) (8 ') formed in the light guide plate (1). In the light guide plate (1) according to any one of Items 3 to 5, the contour line (R) (R) (R) of the cross-sectional shape of the convex stripes (8a) (8) or the concave stripes (8'a) (8 ') is used. ) Is a curve represented by a part of a semicircle, a semiellipse, a parabola, an error function, a cycloid, or an m-th order function (m is a real number), or a sine function or a cosine function (hereinafter simply referred to as a contour curve). According to this, when an absolute value symbol is attached to the above formula expressing the contour line (R) and (R), the negative part is folded back when it is positive. It becomes positive and becomes a continuous semi-cylindrical type as shown in FIG. On the other hand, in the case of a negative value, the positive part is folded back and becomes a negative shape, which is a continuous wave shape as shown in FIG.

Here, the light incident end face (S1) "the reflection side end face (S4) (S
The same applies to 5) ”, the contour line (R a) of the convex line (8 a) or concave line (8 a) is a semicircle, semi-ellipse, parabola, error function, cycloid or m-order function ( Since m is a curve represented by a part of a real number, a sine function or a cosine function, or a positive or negative absolute value thereof, the top (9 a) or concave ((a) of the ridge (8 a) Excessive focusing on the valley part (9'a) of 8'a) is alleviated, and light is scattered over the entire convex stripes (8a) or concave stripes (8'a),
Then, this further strongly scatters in the light guide plate (1) in a direction parallel to the light output surface (S2), and the above-mentioned horizontal scattering effect occurs.
In addition, in general, the height (h) of the ridge (8a) or the ridge (8 ')
The depth (h ') of the valley in (a) is the width (W) of the base of the ridge (8a) or the ridge.
The larger the aperture width (W ') of (8'), the stronger the scattering property. This point is the same for the light emitting surface (S2) and the reflecting surface (S3), and further, in the portion corresponding to the top portion (9) of the convex stripe (8) or the valley portion (9 ') of the concave stripe (8'). The generation of bright lines can be suppressed.

<Claim 10> is the second embodiment of the shape of the convex stripes (8a) (8) or the concave stripes (8'a) (8 ') formed on the light guide plate (1) (see FIG. 10). ), "In the light guide plate (1) according to any one of claims 3 to 5, the ridges (8a) (8) or the concave lines (8'a) (8 ') in the cross-sectional contour line ( R a) Regarding (R), the top (9) of the ridges (8 a) (8)
A) (9) or concave line (8'a) (8 ') valley (9'a) (9') to the above-mentioned convex line
(8a) (8) or one of the contour side lines (r1a) (r1) leading to the concavo-convex forming surface where the concave streak (8'a) (8 ') is formed is a semicircle or a semi-ellipse, a parabola , An error function, a cycloid, or a part of an m-th order function (m is a real number), a sine function, or a cosine function, and the other half of the contour side surface line (r2 a) (r
2) is composed of a straight line which is perpendicular or inclined to the concavo-convex forming surface ”.

In this case, in the light incident end surface (S1), the curved surface side is divided into left and right about the center of the light incident end surface (S1),
When they are concave surfaces facing the reflection side end surface (S4) side adjacent to the light incident end surface (S1) (see FIG. 10), the light incident on the curved surface indicated by the contour side surface line (r1) is the reflection side end surface. The light will be scattered more strongly on the (S4) side, exhibiting an excellent horizontal scattering action. Further, the light reflected from the light guide plate (1) toward the light incident end surface (S1) is also strongly scattered toward the reflection side end surface (S4) side, resulting in enhancing the horizontal scattering effect.

<Claim 11> is as shown in FIG. 11, and “Light guide plate (1) according to any one of claims 3 to 5 is provided.
In, the top (9 a) (9) of the ridge (8 a) (8) or the concave line (8 'a)
Adjacent to the valley of (8 ') (9'a) (9'), the ridge (8 ')
(8) Or two contour side lines (ra i) (rb a) (ra) (rb) that form the contour line (R a) (R) of the cross-sectional shape of the concave line (8 'a) (8') ) Is a straight line, and the contour side lines (ra i) (rb a) (ra a) for the concavo-convex forming surface on which the convex stripes (8 ') (8) or the concave stripes (8'a) (8') are formed. ) (rb) are formed so that the inclination angles (Δ) (γ) are different from each other ”.

In this case, at the light incident end surface (S1), the tilt angle
(Δ) is smaller than the inclination angle (γ) “that is, (Δ) <(γ)”, and the contour side lines (ra i) and (rb a) are left and right about the center of the light incident end surface (S1). If the contour side line (ra i) with a large inclination faces the reflection side end face (S4) side adjacent to the light incident end face (S1), the contour side line (ra i) is divided and symmetrically arranged. The light incident on is strongly scattered toward the reflection side end surface (S4) side, and exhibits an excellent horizontal scattering action. Also, the light guide plate (1)
The light reflected toward the light incident end surface (S1) is also strongly scattered toward the reflection side end surface (S4) side, resulting in enhancing the horizontal scattering effect.

<Claim 12> is shown in FIG. 15 (in this figure, vertical convex stripes formed on the light incident end face (S1) and the reflection side end faces (S4) (S5)).
(8a) or concave line (8'a) and convex line (8) or concave line (8 ') formed on the light emitting surface (S2) and the reflecting surface (S3) are shown in one drawing. is there. ), "In the light guide plate (1) according to any one of claims 3 to 5, the convex stripes (8a) (8) or the concave stripes are provided.
Regarding the cross-sectional shape of (8'a) and (8 '), the ridge (8a) (8) or the concave ridge (8')
(A) (8 ') (8') is formed and the convex stripes (8a) (8) or concave stripes (8'a) (8 ') rise from the boundary between the convex stripes (8a) (8a) ) Side or falling concave line (8'a) (8 ') contour side line (ra i) (rb
B) (ra) (rb) are formed by straight lines, and the contour side line
(ra a) (rb a) (ra) (rb) Apex (9 a) (9) or valley (9 'a) (9')
Is formed of a curved line '', and in this case as well, the tops (9 a) (9) or the concave lines (8'a) (8 ') of the convex stripes (8a) (8) are Excessive focusing on the valley (9'a) (9 ') is alleviated, and the light-incident end face (S
1) and the reflection side end faces (S4) (S5) produce the above-mentioned excellent horizontal scattering effect, and the light emission face (S2) and reflection face (S3) suppress the generation of bright lines. become.

<Claim 13> is a convex strip (8a) (8) or a concave strip (8'a).
Regarding the surface condition of (8 ′) (see FIG. 19), “claims 3 to 1”
In the light guide plate (1) according to any one of 2 above, the ridges (8 a) (8)
(9a) (9) or the valley (9'a) (9 ') of the groove (8'a) (8') and its inclined side surface are composed of irregular and smooth irregular curved surfaces. ] Characterized by that.

According to this, in the longitudinal concave / convex ridges (8a) (8'a) of the light incident end surface (S1) or the reflection side end surfaces (S4) (S5),
Since it becomes more diffusely reflective, the horizontal scattering degree can be increased. Concave / convex stripes (8) on the light emitting surface (S2) or reflecting surface (S3)
In the case of (8 '), when the pitch (P) is so rough as to exceed 200 μm, a plurality of parallel bright lines appear at right angles to the light incident end surface (S1) and along the uneven lines (8) and (8'). If the ridges (8) and the ridges (8 ') are composed of irregular and smooth concave and convex mirror-like curved surfaces, the bright lines are eliminated.

Since the uneven mirror-like curved surface is formed by transferring the shape of the mold cavity surface, the shape of the cavity surface is irregular and smooth. As the method for forming the cavity surface, for example, a large number of parallel marking grooves (not shown) are formed on the cavity surface by scribing, followed by mechanical polishing with an abrasive such as buffing,
It can be obtained by eliminating the “flickering” by electrolytic polishing, plating, or chemical etching. The unevenness of the cavity surface can be changed by changing the marking method.
Can be configured, and the shape of the marking groove can be any desired shape depending on the shape of the marking tool.

When a transparent resin such as an acrylic resin is molded using this mold, the irregularities having the smooth irregular curved surface are precisely transferred to the acrylic plate, and the tops (9) of the ridges (8) are transferred.
Alternatively, the light guide plate (1) is formed in which the valley portion (9 ′) of the concave line (8 ′) and the inclined side surface thereof are formed of smooth uneven curved surfaces. Further, since the above-mentioned cavity surface has been polished, it is finished in a mirror surface state, and the transfer surface is also in a mirror surface state although it is formed of irregular irregular curved surfaces. Further, the pitch (P) of the marking groove is the light incident end surface (S1), the reflection side end surface (S
4) In the case of (S5), an appropriate one is selected from 10 μm to 1,000 μm, and in the light emitting surface (S2) or the reflecting surface (S4), an appropriate one is selected from 10 μm to 600 μm. To be selected.

<Claim 14> is “the light guide plate (1) according to any one of claims 3 to 13 in which the ridges (8a) (8) or the ridges are provided.
(8'a) (8 ') or groove line (11a a) (11b a) (11a) in which a convex strip (8a) (8) and a concave strip (8'a) (8') are a set. ) (11b) are formed so as to intersect with each other '. (Refer to FIG. 14) In FIG. 14, the case where the ridges (8a) and (8) or the ridges (8'a) and (8 ') are formed in one direction and the case where they are formed at the same time are simultaneously performed. In the drawing showing only the solid line or the phantom line, the groove line (11a a) composed of the convex stripes (8a) or the concave stripes (8'a) is the edge line (S1) on the light incident end surface (S1). The groove array (11a) formed in one direction at a right angle or close to E1) and composed of the convex stripes (8) or the concave stripes (8 ') is formed on the light emitting surface (S2) or the reflecting surface (S3). Light incident end face
In this example, the edge line (E1) or (E2) of (S1) is formed in one direction at a right angle or an angle close thereto. On the other hand, by adding an imaginary line, the convex stripes (8a) (8) or the concave stripes (8'a)
Indicates that (8 ') intersects. In this figure, the reflection side end face (S
4) Although the convex line (8a) or the concave line (8'a) in the intersecting state of (S5) is not shown, the intersecting state is the same as the light emitting surface (S2) or the reflecting surface (S3).

The ridges on the light emitting surface (S2) or the reflecting surface (S3)
(8) or the cross groove row (11a) (11b) composed of the groove (8 ')
The inclination angle (m) (n) with respect to the light incident end surface (S1) is generally m
= N, but it is desirable to set different values (m ≠ n) in order to avoid the moire phenomenon. In this case, crossing groove row (11
The pattern of the light emitting surface (S2) formed by (a) and (11b) is a diamond pattern. There is no such restriction on the light incident end face (S1) and the reflection side end faces (S4) (S5).

<Claim 15> is, “In the light guide plate (1) according to any one of claims 3 to 14, adjacent ridges (8b) are adjacent to each other.
(8) Or concave stripe (8'a) (8 ') or convex stripe (8a) (8) and concave stripe (8'a)
(8 '), the convex portion (8a) (8) and the concave portion (8'a) (8') are respectively formed on the flat surface portion (Hi) (H )
Has been formed ”. (Figure 1
(See 7 (b))

Theoretically speaking, the convex stripes (8a) (8) or the concave stripes (8 ')
(A) (8 ') does not have a flat part (H) (H) and is formed in contact with each other, the luminance performance is higher, but the adjacent ridges (8a) (8a) ) The tip of the gap between or
(8'a) Since the tip of the side wall between (8 ') becomes excessively narrow, it is difficult to transfer accurately at the time of molding, and the yield decreases accordingly and it becomes expensive, and it is easily scratched. . Flat part (H)
By passing through (H), the above-mentioned difficulty is eliminated, molding becomes easy, and it contributes to cost reduction.

<Claim 16> is “the light guide plate (1) according to any one of claims 3 to 15, wherein the light emitting surface (S2) and the reflecting surface are
(S3) and ridges on the reflection-side end surface (S4) in contact with the light incident end surface (S1)
The height of (8a) or the depth of the concave streak (8'a) is formed so as to increase as the distance from the light incident end face (S1) increases. ' As a result, the scattering of light is strengthened as the distance from the light entrance end surface (S1) increases, which gradually increases the evenness of the light, making the overall brightness distribution of the light exit surface (S2) uniform and improving the uniformity of the screen. Plan.

<Claim 17> states that, in the light guide plate (1) according to any one of claims 1 to 16, the reflecting surface (S3) or the light emitting surface (S2) or the reflecting surface (S3) and the light emitting surface (S2 ), The white printed dots (6) or concave or convex grain dots (6a) are formed so that the density or area thereof gradually increases as the distance from the light incident end surface (S1) increases. The light guide plate is characterized by "uniformizing the brightness" by reflecting white printed dots (6) or concave or convex grain dots (6a).
Even in the back of (1) (= the part near the reflection-side end surface (S5)), the light emission rate does not decrease, and the brightness uniformity of the entire screen can be increased.

<Claim 18> means that, in the light guide plate (1) according to any one of claims 1 to 17, the reflecting surface (S3) or the light emitting surface (S2) or the reflecting surface (S3) and the light emitting surface (S2). ), The white print dots (6) or concave or convex wrinkle dots (6a) are formed so as to increase the density or area thereof so as to substantially coincide with the dark part (2b) generated on the light output surface (S2). Characterize things. As a result, the light output rate of the portion where the dark portion (2b) is likely to occur is improved,
It is possible to strengthen the elimination of the dark portion (2b) by the white printed dots (6) or the concave / convex grain dots (6a).

<Claim 19> is a case where the light guide plate (1) is of a diffusion type in a conductor. In the light guide plate (1) according to any one of claims 1 to 18, the light guide plate (1) is provided inside the light guide plate (1). The particles from the light-scattering transmitter are dispersed so that the luminance from the light-emitting surface (S2) is made uniform. ”

On the light emitting surface (S2) or the reflecting surface (S4), the groove rows (11a) (11
a ') or / and (11b) (11b') is formed,
The vertical and horizontal light-collecting effect is enhanced for the light output surface (S2) and the convex stripes
Even if the pitch of (8) or the groove (8 ') is made coarser, the effect of suppressing the generation of bright lines is large. Especially, the ridge (8) or the ridge (8 ')
The groove rows (11a) (11a ') (11b) (11b') of the light guide plate (1)
When it is provided on both 2) and the reflecting surface (S3), a higher light-collecting effect can be obtained as compared with the case where it is provided on one surface. In addition, the inclusion of light scattering particles also increases the horizontal scattering of light, which leads to improved screen uniformity.

<Claim 20> is a specific example of the grain dots (6a) and (6a). In the light guide plate (1) according to any one of claims 6 and 18, concave or convex grain dots (6a) are provided. (6a) is formed in the shape of a cone ". "Conical" here
The term "cone" includes a cone, a triangular pyramid, a quadrangular pyramid and the like having an irregular cross section.

<Claim 21> refers to “a light guide plate (1) according to any one of claims 1 to 20 and a light incident end surface (S1) provided at at least one end of the light guide plate (1). Light source installed
(2), a reflector (7) arranged behind the light source (2) for condensing the light from the light source (2) on the light incident end surface (S1), and the light emitting surface of the light guide plate (1) (S2) Diffusion sheet (3b) disposed on the light emitting surface and one or two directional sheets (3a1) (3a2) disposed on the light emitting surface as necessary, and light output of the light guide plate (1) A reflection sheet arranged along the reflection surface (S3) on the opposite side of the surface (S2)
(4) and end face reflection tapes (5a) and (5b) provided on the reflection side end faces (S4) and (S5) of the light guide plate (1) ”.

According to this, since the light guide plate (1) according to any one of claims 1 to 20 is used, the light incident end surface (S1) is used.
Even if a light source (2) shorter than the lateral width is used, a dark frame (2b) does not occur at both ends of the light incident end surface (S1) and a narrow frame can be achieved. Also, since the horizontal scattering effect can be enhanced, it is possible to achieve a screen with high brightness and high uniformity. Also,
By forming the groove array (11a) on the light emitting surface (S2) or the reflecting surface (S3) of the light guide plate (1), it is possible to reduce one of the directional sheets (3a1).

<Claim 22> claims “light emitting surface (S2) and light incident end surface”.
Edge line (E1) with (S1) or light output surface (S2) and reflection side end surface
(S4) The ridges (8a) or the ridges (8'a) or the ridges (8a) and the ridges (8a) that are substantially parallel to each other so as to be orthogonal or inclined to the edge line (E3) with (S4). A light guide plate (1) having stripes (8 ') alternately formed on the light incident end surface (S1) and at least one reflection side end surface (S4) (S4), and at least one end of the light guide plate (1) Is arranged along the light-incident end surface (S1), and its electrode part (2a) is placed behind the light source (2) and the short light source (2) that extends over the light-incident end surface (S1). The reflector (7) is installed to collect the light from the light source (2) on the light incident end surface (S1), and the uneven surface is arranged on the light emitting surface (S2) with the uneven surface facing the light emitting surface (S2). One directional sheet (3
a2), the directional sheet (3a2) if necessary a diffusion sheet (3b) provided on the directional sheet (3a2), the light guide surface (S2) of the light guide plate (1) opposite the reflection surface (S3). ) Reflective sheet placed along
(4) and end face reflection tapes (5a) and (5b) provided on the reflection side end faces (S4) and (S5) of the light guide plate (1) ”.

According to this, the light incident end surface (S1) of the light guide plate (1)
Also, since at least one reflection side end surface (S4) (S4) is formed with a convex strip (8a) or a concave strip (8'a), even if the uneven surface is directed toward the light emitting surface (S2) side. The light-transmitting sheet (3a2) to the light-emitting surface (S
2) The light guide plate (1) does not become a mirror surface even if it is placed on
The reflection of (2) could be prevented.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The light guide plate (1) having the basic shape of the present invention is described below.
Then, an example of the planar illuminator (A) using the light guide plate (1) will be described. The light guide plate (1) is a light source (2) as shown in FIG.
The light-incident end surface (S1) in which is disposed is formed wide, the light-reflecting end surface (S5) on the opposite side of the light-incident end surface (S1) is formed narrow, and both end surfaces (S1) ( Reflection surface for light output surface (S2) between (S4)
(S3) is formed to be inclined, and its cross section is formed to have a wedge shape. The light reflection end face between the light incident end face (S1) and the light reflection end face (S5) of the light guide plate (1) is (S4).
Indicated by In this embodiment, the light exit surface (S2) is perpendicular to the light entrance end surface (S1), and the reflection surface (S3) is inclined with respect to the light entrance end surface (S1). However, on the contrary, the light output surface
(S2) is inclined with respect to the light incident end surface (S1), and the reflecting surface (S3)
It goes without saying that a light beam having a right angle to the light incident end surface (S1) may be used. As the light guide plate (1),
Not limited to the wedge type, there are various types such as a parallel plate type and a V type as shown in FIG. 6, and there are a light source (2) one-lamp type and two-lamp type. The material of the light guide plate (1) is generally an acrylic plate having excellent light transmittance.

The light scattering means (L) provided on the light guide plate (1) is
In the case of only the light incident end surface (S1), it may be formed on at least one of the reflection side end surfaces (S4) (S5) in addition to the light incident end surface (S1). Specific examples of the light scattering means (L) The first is the light output surface (S
2) Vertical ridges (8a) or concave ridges (8'a) or ridges (8a) and concave ridges (8a) formed alternately or randomly. The ridges (8a) or the ridges (8'a) are composed of various curved surfaces described later, and the pitch (P) of the ridges (8a) or the ridges (8'a) is 10μm. ˜1,000 μm, and the surface is formed in a mirror state. In addition, the ridge (8 a) or the ridge
The angle between (8'a) and the edge line (E1) of the light incident end surface (S1) is 7
It is 0 ° to 90 °.

On the other hand, white printed dots (6) or grain dots (6a) are formed on the light exit surface (S2) and / or the reflection surface (S3) or both of them so that the area density thereof gradually increases as the distance from the light entrance end surface (S1) increases. It is provided. Light emitting surface (S2) or reflecting surface (S3)
Is a flat surface, or the groove lines (11a) (11b) of the convex stripes (8) or the concave stripes (8 ') are formed at right angles or incline with respect to the edge line (E1) of the light incident end surface (S1). Has been done. The convex ridges (8) or concave ridges (8 ') formed on the light emitting surface (S2) or the reflecting surface (S3) are also composed of various curved surfaces described later, and the pitch between the ridges (8)
(P) is 10 μm to 600 μm, and the surface thereof is a mirror surface. The included angle between the ridge (8) or the ridge (8 ′) and the edge line (E1) of the light incident end surface (S1) is 70 ° to 90 °.

Convex ridges (8a) or concave ridges (8'a) constituting the light scattering means (L) and convex ridges (8) or concave ridges formed on the light emitting surface (S2) or reflecting surface (S3) The contour line (R) and (R) of the cross section of (8 ') is, for example, a part of a semi-arc or semi-ellipse, a sine function, a cosine function, a parabola or an error function, a cycloid, and an m-order function (m is a real number). A curved line (hereinafter, simply referred to as a contour curve).
An arc is preferable from the standpoint of ease of mold production. In terms of the horizontal scattering ability of the light incident end surface (S1) and the reflection side end surfaces (S4) (S5), a V-shaped cross section is preferable, but in this case, the convex stripe (8a) or concave stripe (8'a) is used. If it is rougher than 500 μm, its top
(9a) or valley (9'a) bright line occurs, this is the light emitting surface (S2)
Therefore, using a sine function, a parabola, an ellipse, or an error function does not cause a bright line at the top (9a) or valley (9'a) of the light emitting surface (S2). Is preferable.

A cold cathode tube which serves as a light source (2) is arranged along the light incident end surface (S1) of the wedge-shaped light guide plate (1). Behind the cold cathode tube (2), a reflector (7) formed in a concave surface is generally installed. Further, a reflection sheet (4) is installed below the reflection surface (S3) of the wedge-shaped light guide plate (1).

When the light emitting surface (S2) is a flat surface, two directional sheets (2) are formed on the light emitting surface (S2) with the groove rows (11) and (12) intersecting each other. 3a1) and (3a2) are laid, and if the groove array (11a) is formed on the light output surface (S2), it intersects with the groove array (11a) and the above-mentioned one directional sheet (3a2) The groove line (12) is the edge line of the light-incident end surface (S1) of the wedge-shaped light guide plate (1).
Lay so as to be parallel or slightly inclined to (E1). A large number of groove rows (11) and (12) are formed in parallel on the directional sheets (3a1) and (3a2).

Part of the light emitted from the light source (2) is
The light is directly incident on 1), and the rest is reflected by the reflector (7) and incident. The incoming light goes straight through the light guide plate (1) after being refracted, but it is preferential in the horizontal direction by the vertical convex strips (8a) or vertical concave strips (8'a) that are the light scattering means (L). Will be scattered in. Most of the scattered light is reflected by the reflection surface (S3) or the reflection sheet (4) to change its course, and most of it is the light emission surface (S2).
It is emitted from, but the rest repeats countless reflections.
At this time, as described above, the vertical ridge (8a) which is the light scattering means (L).
And vertical recesses (8'a) preferentially scattered in the horizontal direction,
And the end face reflection tape arranged on the light reflection end faces (S4) (S5)
Since the light is reflected by (5a) and (5b), the light finally returns after passing through the light guide plate (1) by being folded back innumerably. Also,
A part of the light reflected substantially horizontally on the light exit surface (S2) or the reflection surface (S3) at the reflection side end surface (S4) (S5) proceeds toward the light entrance end surface (S1). Also in the case of the light incident end face (S1) is preferentially scattered in the horizontal direction by the vertical ridges (8) and the vertical ridges (8 ') that are the light scattering means (L), and finally repeated by repeating reflection. Is lit up.

When the groove array (11a) is formed on the light emitting surface (S2) or the reflecting surface (S4), the light introduced into the light guide plate (1) is the convex stripe (8) or the concave stripe. It is guided to the inner part of the light guide plate (1) by (8 ') and reaches the light reflecting end surface (S5) opposite to the light incident end surface (S1). At the same time, the ridge (8) or the ridge (8 ') has a distribution of the light output angle in the direction parallel to the light incident end surface (S1) of the light emitted from the light output surface (S2) perpendicular to the light output surface (S2). Focus on the direction. Here, since the contour line (R) of the constituent surface of the convex stripe (8) or the concave stripe (8 ′) is formed by a curve selected from the various curves,
(9) or valley (9 ') excessive light is relaxed and the top (9) or valley (9') is diffused throughout the light, and the expression of bright lines is suppressed,
Therefore, the pitch of the ridges (8) or the ridges (8 ') can be made coarser.

Subsequently, the groove array (12) of the directional sheet (3a2) installed on the convex stripe (8) or the concave stripe (8 ′) is the light incident end surface (S1).
Since it is installed so as to be in a direction substantially parallel to, the light output angle distribution in the direction perpendicular to the light incident end surface (S1) is condensed here in the direction perpendicular to the light output surface (S2). as a result,
The light output angle distribution of the light passing through the upper directional sheet (3a2) is focused on the optical axis perpendicular to the light output surface (S2). If this condensed light is too sharp, a directional sheet (3
The diffusion sheet (3b) is installed on top of a2).
Light is diffused uniformly by (3b), and as a result, light is emitted uniformly and with high brightness on the entire surface of the light emitting surface (S2).
Groove row (12) of the directional sheet (3a2), in the case of a purchased product, the cross-sectional shape is a right angle or a simple isosceles triangle, in the top (9) of the groove row (12) of the directional sheet (3a2). When the contour line of the cross section is formed in a curved shape, too, the excessive condensing on the apex (9) is alleviated and the light diffuses over the entire apex (9), which suppresses the development of the bright line. The degree of light collection is alleviated, and the diffusion sheet (3b) can be omitted.

When the ridges (8) or the ridges (8 ') are not formed on the light emitting surface (S2) or the reflecting surface (S3), two directional sheets (3a1) (3a2) are used as in the conventional case. , The ridges (8) are overlapped so as to intersect, and the diffusion sheet (3b) is further laid thereon. If necessary, at least one of the light emitting surface (S2) and the reflecting surface (S3) has a ridge (8) or a ridge.
White printed dots (6) so that the density or area gradually increases toward the back on a flat surface where (8 ') is not formed.
That is, the grain dots (6a) are formed.

In the above description, the case where the light guide plate (1) is wedge-shaped has been described as an example, but of course the present invention is not limited to this, and a one-lamp parallel plate type (not shown) or a two-lamp parallel plate type is used. Various things such as a thing (not shown) or a two-lamp type V type as shown in FIG. 5 are also included. Further, the material of the light guide plate (1) is preferably an acrylic plate as described above, but is not limited to this, of course,
Any material may be used as long as it has excellent light transmittance. Further, in the above, the case where the light guide plate (1) is transparent is taken as an example, but it is needless to say that the present invention is not limited to this, and may be an in-conductor diffuser plate in which fine particles are diffused.

The convex stripes (8a) and concave stripes (8'a) that are the light scattering means (L)
Alternatively, the ridges (8) formed on the light emitting surface (S2) or the reflecting surface (S3)
The ridges (8 ') and the ridges (8') may be alternately formed or may be random, and the ridges (8a) (8) and the ridges (8'a) (8 ') are flat. In some cases, a part (H) and (H) may be formed. Also, ridges
(8a) (8) and concave stripes (8'a) (8 ') may be crossed on the same plane, and this is a convex stripe formed on the light emitting surface (S2) or the reflecting surface (S3).
In the case of (8) or the concave strip (8 '), it is possible to omit both the directional sheets (3a1) and (3a2). When the ridges (8a) (8) and the concave ridges (8'a) (8 ') are formed by crossing, one ridge
(8a) The height of (8) or the depth of the concave (8'a) (8 ') with respect to the height of the other convex (8a) (8) or the concave (8'a) You may change the depth of (8 '). Thereby, the light guiding property is improved as compared with the case where the height or the depth is the same.

A second example of the light scattering means (L) is a case where the light scattering means (L) is a concave or convex wrinkle dot (6a), and a third example is a light emitting surface (S2). Edge line (E1)
In the case where the surface “= light incident end surface (S1), reflection side end surface (S4) (S5)” in the direction along (E3) or (E5) is a concave surface, the action and effect are as described above.

(Embodiment 1) A 1-lamp wedge-shaped light guide plate (1) having an area of 10.4 ", as shown in FIG. 20, is an electrode shadow" = dark part (2b) "which is a shadow of the electrode part (2a). The density of the white print dots (6) in the part corresponding to the dark part (2b) was increased, and the convex line (8a) was added to the light-incident end surface (S1) at a pitch of 400 μm as an edge line.
Formed at a right angle to (E1). The dark area (2b) due to the shadow of the electrode, which was not erased only by adjusting the dot density, was completely eliminated, and a surface type illuminator with a beautiful screen with high uniformity was obtained. (Table 1,
2) Tables 1-6 show that the screen of the light guide plate (1) is 5
The light-incident end surface (S1) side is divided into A, the zone closest to the light source (2) is A, and B to E are spaced apart from the light source (2).
And Then, the whole screen was divided into 5 × 5 = 25, and the luminance was measured every other one. Tables 1 and 2 are one set, Tables 3 and 4 are one set, Tables 5 and 6 are one set, Tables 1 and 2 are Example 1, Tables 3 and 4 are Example 2, Tables 5 and 6. Correspond to Example 3, respectively. Further, Table 1 is a conventional example of Example 1, and Table 2 is a case where the convex strips (8a) are provided on the light incident end surface (S1) at a pitch of 400 μm. In Table 1, the brightness of A- is 771 cd / m ² , which is darker than the others and is the dark part (2b). On the other hand, in Table 2, the brightness of A- is 1,
It is 042 cd / m ^2, which is an improvement. Further, the uniformity ratio represented by the minimum luminance ÷ maximum luminance × 100 is 5 in Table 1.
Although it is as low as 2.27, it is as high as 71 in Table 2, showing an improvement in the uniformity.

(Embodiment 2) In the 1-lamp type wedge-shaped light guide plate (1) having a width of 10.4 ", the dark portion (2b) which is the shadow of the electrode portion (2a) is generated as shown in FIG. -Type light guide plate (this is a light guide plate in which unevenness is added to the reflection surface to give grain dots and the brightness and uniformity are adjusted) and the light incident end surface (S1) and the opposite reflection side end surface (S5) The ridges (8a) were formed at a pitch of 500 μm at right angles to the edge lines (E1) and (E5) .The dark area (2b), which was not erased only by adjusting the dot density, was completely eliminated, resulting in a beautiful screen with high uniformity. A surface type illuminator was obtained (see Tables 3 and 4). Table 3 is a conventional example of Example 2, and Table 4 shows the light incident end surface (S
This is the case where convex strips (8) are formed at a pitch of 500 μm on 1) and the reflection side end surface (S5) on the opposite side. In Table 3, A-,
, The brightness is 894, 854, 763 cd / m ² and the light source
The (2) side is also darker than the back side, and in particular, A- is the darkest and is the dark part (2b). On the other hand, in Table 4, the brightness of A-, 882, 843, 835 cd /
Improvement of A- which is m ² and is the darkest part (2b) (763 → 8)
35) can be seen. In addition, the uniformity is 51.0 in Table 3.
While it is as low as 3, it is as high as 58.76 in Table 2, showing an improvement in the uniformity. In addition, it is a structural feature of the second embodiment that the step A is darker than the inner part.

(Embodiment 3) "Light emission" is made with the apex angle downward on the flat light emitting surface (S2) of the 1-light type and in-conductor diffusion-type wedge-shaped light guide plate (1) having an area of 10.4 ". Towards the surface (S2) side ”One directional sheet 《Diaart, manufactured by Mitsubishi Rayon Co., Ltd.》 (3a1)
Was laid. The light guide plate (1) has not only the light incident end face (S1) but also the other reflection side end faces (S4) (S5) with a V-shaped cross section (8'a).
Were provided at a pitch of 300 μm. In each case, the reflection of the cold cathode fluorescent lamp (2), which was not eliminated by the light guide plate (1) without the above-mentioned recessed line (8 '), was completely disappeared, and a beautiful screen surface with a high degree of uniformity. Type illuminating body was obtained, and two directional sheets (3a1) (3a2), which were required before, were also included in (3a2).
It was possible to reduce the number to one and it was possible to achieve a significant cost reduction. The reason is that when the directional sheet (3a1) is arranged on the light emitting surface (S2) with the apex angle downward, the apex angle portion of the directional sheet (3a1) functions as a prism, and the light emitting surface (S2).
A part of the light emitted from the light guide plate is converted into the light emitted, and the remaining part is reflected and returned to the inside of the light guide plate (1).
(1) The light will be emitted after repeating the reflection within.
The horizontal reflection of the reflections is enhanced by the light incident end face (S1) and the other reflection side end faces (S4) (S5), and the reflection of the cathode tube (2) is completely eliminated. At the same time, the brightness distribution on the screen is also eliminated. By such an action, it was possible to reduce the number of directional sheets to one. (See Tables 5 and 6) In Table 5, the luminances of A- and 975 are 975 cd and 821 cd / m ^2.
It is darker than the others and is in the dark area (2b). On the other hand, in Table 6, the brightness of A- is 1,235, 1,21.
It was 1 cd / m ² and was improved. Further, the uniformity is as low as 52.1 in Table 5, whereas it is as high as 67.1 in Table 6, showing an improvement in the uniformity.

[0061]

[Documents containing chemical formulas, etc.]

[0062]

As described above, since the light guide plate of the present invention is provided with the vertical ridges or recesses only on the light incident end face or on at least one of the light incident end face and the reflection side end face. , When using a short light source that is shorter than the width of the light-incident end face and has electrodes on both ends of the light-incident end face, it is possible to eliminate the dark areas that occur at both ends of the light-incident end face due to the shadows of the electrodes. Therefore, it is possible to prevent the narrowing of the frame of the liquid crystal screen due to the use of the short light source and the reflection of the light source,
Furthermore, we were able to achieve high brightness and high uniformity of the screen. Further, by forming a groove array of convex stripes or concave stripes on the light emitting surface or the reflecting surface, the light guiding property and the directivity are improved, and the screen is evenly distributed in cooperation with the vertical convex stripes or concave stripes. The improvement of the degree and the reduction of the directional sheet could be achieved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment of a planar lighting body according to the present invention.

FIG. 2 is an exploded perspective view of a second embodiment of the surface illumination body according to the present invention.

FIG. 3 is an exploded perspective view of a third embodiment of the surface illumination body according to the present invention.

FIG. 4 is an exploded perspective view of a surface illuminating body according to a fourth embodiment of the present invention.

FIG. 5 is an exploded perspective view of a fifth embodiment of the planar illuminator according to the present invention.

FIG. 6 is an exploded perspective view of a sixth embodiment of the planar illuminator according to the present invention.

FIG. 7 is an exploded perspective view of a seventh embodiment of the planar lighting body according to the present invention.

FIG. 8 is an exploded perspective view of an eighth embodiment of the surface illumination body according to the present invention.

FIG. 9 is an enlarged side view of the end portion of the first embodiment of the light incident end surface of the light guide plate as seen from the light source side of the present invention.

FIG. 10 is an enlarged side view of the end portion of the second embodiment of the light incident end surface of the light guide plate as seen from the light source side of the present invention.

FIG. 11 is an enlarged side view of an end portion of the third embodiment of the light incident end surface of the light guide plate as seen from the light source side of the present invention.

FIG. 12 is an enlarged side view of the end portion of the fourth embodiment of the light incident end surface of the light guide plate seen from the light source side of the present invention.

FIG. 13 is an enlarged side view of the end portion of the fifth embodiment of the light incident end surface of the light guide plate as seen from the light source side of the present invention.

FIG. 14 is a perspective view of the planar illuminator according to the present invention when viewed from above.

FIG. 15 is a partially enlarged cross-sectional view when the light scattering means of the present invention or the convex / concave streaks formed on the light emitting surface or the reflecting surface are wavy.

FIG. 16 is a partially enlarged cross-sectional view in the case where the light-scattering means of the present invention or the ridges formed on the light-exiting surface or the reflecting surface are of the kamaboko type.

FIG. 17 (a) = Partially enlarged cross-sectional view when the light scattering means of the present invention or the concave stripes formed on the light emitting surface or the reflecting surface has a continuous waveform. (B) = The light scattering means or the light emitting surface of the present invention An enlarged cross-sectional view for explaining a light passing state in the concave stripe in which a flat surface portion is arranged between the concave stripes formed on the reflecting surface.

FIG. 18 is a partially enlarged cross-sectional view of a case where convex portions and concave portions formed on the light scattering means or the light emitting surface or the reflecting surface of the present invention are alternately formed, and a flat surface portion is provided between them.

FIG. 19 is a partially enlarged perspective view of a ridge formed by a mold after polishing the cavity surface of the present invention.

FIG. 20 is a plan view of a conventional example in which dark portions due to electrode shadows occur at both ends of a light incident end surface.

FIG. 21 is a plan view of a conventional example in which a light source is reflected at both ends of a light incident end face.

[Explanation of symbols]

(1) ... Light guide plate (2) ... Light source (6a) (6) ... White printed dot (6a a) (6a) ... Cibo dot (8a) (8) ... Convex ridge (8'a) (8 ') … Concave line (9 a) (9)… Top part (9 a) (9 ′)… Valley part (R a) (R)… Contour line (S1)… Incoming light end face (S2)… Emitting surface (S3) … Reflecting surface (S4) (S5)… Light reflecting end surface (L)… Light scattering means

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[Procedure amendment]

[Submission date] May 29, 1996

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Title: Light guide plate and planar illuminator using the light guide plate

Claims (22)

[Claims] 1. A front surface is a light exit surface, a back surface is a reflection surface, one end surface thereof is a light entrance end surface, and the other side surface is a reflection side end surface. In the light guide plate that scatters the light entering from the light source arranged and emits the light from the light exit surface, among the light entering inside from the light entrance end surface, the scattering of the light in the direction parallel to the light exit surface. A light guide plate, characterized in that light-scattering means for strengthening is formed on a light-incident end surface. 2. The front surface is a light emitting surface, the back surface is a reflecting surface, one side end surface thereof is a light incident end surface, and the other side end surface is a reflecting side end surface. In the light guide plate that scatters the light incident from the light sources arranged along the light exit surface and emits the light from the light exit surface, of the light entering inside from the light entrance end surface, the light in the direction parallel to the light exit surface A light guide plate, characterized in that light scattering means for enhancing scattering is formed on a light incident end surface and at least one reflection side end surface. 3. The front surface is a light emitting surface, the back surface is a reflecting surface, one side end surface thereof is a light incident end surface, and the other side end surface is a reflecting side end surface. In the light guide plate that scatters the light entering from the light sources arranged along the light exit surface and emits the light from the light exit surface, among the light entering inside from the light entrance end surface, the light in the direction parallel to the light exit surface A light scattering means for strengthening scattering is formed on the light incident end surface, and the light exit surface or the reflection surface located on the opposite side or both the light exit surface and the reflection surface, the edge line or the reflection surface between the light exit surface and the light entrance end surface. And ridges or recesses or ridges and recesses are alternately formed on the light emitting surface or the reflecting surface or both the light emitting surface and the reflecting surface so as to be orthogonal or inclined to the edge line of the A light guide plate that is characterized by being. 4. The front surface is a light emitting surface, the back surface is a reflecting surface, one side end surface thereof is a light incident end surface, and the other side end surface is a reflecting side end surface. In the light guide plate that scatters the light incident from the light sources arranged along the light exit surface and emits the light from the light exit surface, of the light entering inside from the light entrance end surface, the light in the direction parallel to the light exit surface Light-scattering means for enhancing scattering is formed on the light-incident end surface and at least one reflection-side end surface, and the light-exit surface or the light-incident end surface is formed on the light-exit surface or the reflection surface located on the opposite side or both the light-exit surface and the reflection surface. The convex line or the concave line or the convex line and the concave line are alternately arranged so as to be orthogonal or inclined with respect to the edge line of or and the edge line of the light receiving end face and the light emitting surface or the reflecting surface or the light emitting surface and the reflection. A light guide plate characterized by being formed on both sides. 5. The light-scattering means according to claim 1, wherein the light-scattering means is formed so as to be orthogonal or inclined with respect to the edge line of the light-exiting surface, or a convex stripe or a concave stripe that is alternately formed. A light guide plate characterized by being a strip. 6. A light guide plate, wherein the light scattering means according to any one of claims 1 to 4 is a concave or convex wrinkle dot. 7. The light scattering means according to claim 1, wherein at least one of the surfaces of the light output surface facing the edge line is formed in a concave shape in which both ends of the surface project from the central portion. The light guide plate that is characterized by. 8. The light guide plate according to any one of claims 3 to 5, characterized in that the pitch between the convex stripes or the concave stripes or the alternately arranged convex stripes and concave stripes is 10 to 1,000 μm. Light guide plate. 9. The light guide plate according to any one of claims 3 to 5, wherein the contour line of the convex or concave cross-sectional shape is a semicircle, a semiellipse, a parabola, an error function, a cycloid, or m.
A light guide plate characterized by being represented by a curve represented by a part of the following function (m is a real number) or by a sine function or a cosine function. 10. The light guide plate according to any one of claims 3 to 5, wherein, regarding the contour line of the cross-sectional shape of the convex stripe or the concave stripe, the convex stripe or the concave stripe is formed from the top of the convex stripe or the valley of the concave stripe. One contour side line leading to the uneven surface where the
A curve composed of a semi-circle or a semi-ellipse, a parabola, an error function, a part of a cycloid or an m-th order function (m is a real number), a sine function, or a cosine function, and the other half of the contour side line is A light guide plate, characterized in that it is constituted by a straight line which is perpendicular or inclined to the surface on which unevenness is formed. 11. The light guide plate according to any one of claims 3 to 5, wherein the light guide plates are adjacent to each other with a top of the ridge or a valley of the ridge as a boundary, and form a contour line of a sectional shape of the ridge or the ridge. The light guide plate is characterized in that the two contour side lines are straight lines, and the inclination angles of the contour side lines with respect to the concavo-convex forming surface on which the ridges or recesses are formed are different from each other. . 12. The light guide plate according to any one of claims 3 to 5, with respect to the cross-sectional shape of the convex stripe or the concave stripe, an unevenness forming surface on which the convex stripe or the concave stripe is formed, and a convex stripe or a concave stripe. The light guide plate characterized in that the side surface of the convex line rising from the boundary with or the contour side line of the concave line descending is formed by a straight line, and the apex or valley between the side faces is formed by a curved line. . 13. The light guide plate according to any one of claims 3 to 12, wherein the tops of the ridges or the valleys of the ridges and the inclined side surfaces thereof are formed by irregular and smooth uneven curved surfaces. And a light guide plate. 14. The light guide plate according to any one of claims 3 to 13, wherein the ridges or the ridges or the ridges and the ridges forming a set are formed to intersect each other. A light guide plate characterized by. 15. The light guide plate according to any one of claims 3 to 6 and 8 to 14, wherein the convex stripes or concave stripes are formed between adjacent convex stripes or concave stripes or between convex stripes and concave stripes. 2. A light guide plate, characterized in that flat portions are formed so as to correspond to the respective concave and convex forming surfaces. 16. The light guide plate according to any one of claims 3 to 15, wherein the height of the convex line or the depth of the concave line of the reflection side end face which is in contact with the light emitting face, the reflecting face and the light incident end face is the light incident face. A light guide plate characterized in that it is formed so as to change with distance from the end face. 17. The light guide plate according to claim 1, wherein the reflection surface or the light exit surface or both of the reflection surface and the light exit surface gradually increase in density or area as the distance from the light entrance end surface increases. A light guide plate, characterized in that white printed dots or concave or convex wrinkle dots are formed on the surface to equalize the brightness from the light emitting surface. 18. The light guide plate according to any one of claims 1 to 17, wherein a white printed dot is formed on the reflective surface or the light exit surface or both the reflective surface and the light exit surface so as to substantially coincide with a dark portion generated on the light exit surface. A light guide plate, characterized in that concave or convex grain dots are formed so as to increase the density or area. 19. The light guide plate according to any one of claims 1 to 18, characterized in that fine particles serving as a light scattering medium are dispersed in the light guide plate to equalize the brightness from the light exit surface. Light guide plate. 20. The light guide plate according to claim 6, wherein concave or convex grain dots are formed in a pyramid shape. 21. The light guide plate according to claim 1, a light source disposed along at least one end of the light guide plate along a light incident end face, and a light source disposed behind the light source. A reflector for condensing the light from the light source on the light incident end surface, a diffusion sheet arranged on the light emitting surface of the light guide plate, and one or two directivity arranged on the light emitting surface as necessary. Of the light guide plate, a reflection sheet arranged along the reflection surface on the opposite side to the light emitting surface of the light guide plate, and an end face reflection tape arranged on the reflection side end face of the light guide plate. A characteristic surface-type lighting body. 22. A ridge or a groove or a ridge and a groove which are substantially parallel to each other so as to be orthogonal or inclined to the edge line between the light exit surface and the light entrance end surface or the edge line between the light exit surface and the reflection side end surface. Light guide plates in which stripes are alternately formed on the light incident end face and at least one reflection side end face, and arranged along the light incident end face provided on at least one end of the light guide plate,
A short light source whose electrode end is applied to the light incident end surface, and a reflector that is arranged behind the light source and focuses the light from the light source on the light incident end surface, and its uneven surface facing the light exit surface side. A directional sheet disposed on the light emitting surface, a diffusion sheet disposed on the directional sheet as necessary, and a reflecting surface on the opposite side of the light emitting surface of the light guide plate. 1. A surface-type lighting body comprising a reflection sheet arranged along the side and an end face reflection tape arranged on a reflection side end face of a light guide plate.