JPH0961631A - Light guide plate and surface type lighting body using the plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the formation of a groove array and make the groove array hard to flaw, increase yield, and further lower the cost by reducing inexpensive directional sheets by one - two and optically examining the shape of a projection or recessed streak. SOLUTION: The light guide plate 1 which scatters light made incident from a light source 2 arranged on an incident light end surface S1 and projects the light from a light projection surface S has projection streaks 8 or/and recessed streaks formed on the light projection surface S2 or/and reflection surface S3 on its opposite side so that the projection and recessed streaks are parallel to each other and cross the light incidence end surface S1 at right angles or slantingly; and the pitch P of mutually adjacent projection streaks 8 or recessed streaks is 10-600μm and the constitution surfaces of the projection streaks 8 or recessed streaks on the projection surface S2 are finished in a mirror surface shape.

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.

The above-mentioned conventional edge light type light guide plate
(1) is acrylic resin flat plate or wedge type (single lamp type) to V
Type (two-lamp type) is used, white dots (6) are printed on the reflecting surface (S3) or grain is formed, and the reflecting sheet (4) is formed along the reflecting surface (S3). ), And the light output surface (S
2) side, diffusion sheet (3b) and two directional sheets
(3a1) and (3a2) were placed so as to overlap each other. The directional sheet (3a1) (3a2), a large number of groove rows (11) (12) are respectively formed in parallel, one directional sheet (3a1),
The groove array (11) is arranged perpendicular to the light incident end surface (S1), while the groove array (12) of the other directional sheet (3a2) is arranged parallel to the light incident end surface (S1). Has been done. As a result, the incident end face (S
Change the optical path of the light introduced from 1) into the light guide plate (1),
It was close to vertical to the light emitting surface (S2) and achieved high brightness. In addition, a reflector (7) is arranged behind the light source (2), and the light reflection end face (S4) of the light guide plate (1) << including the side face part of the light guide plate (1) >> is end face reflection. A tape (5) is provided.

As described above, the directional sheets (3a1) and (3a2) have a large number of fine groove rows (11) (12) whose cross sections are inverted V-shaped with two sides being equal to each other in parallel. Although it is formed, it is preferable that the pitch of the groove rows (11) and (12) is finer, and if the groove row exceeds 100 μm, the top portion (9) of the groove row is a bright line perpendicular to the cathode tube (2). Then, it appears on the light emitting surface (S2) and cannot be used as the light guide plate (1). When the pitch of the groove rows (11) (12) becomes fine, the directional sheet (3
a1) (3a2) die manufacturing requires advanced technology, is expensive, and the groove row of the die for forming the minute groove rows (11) and (12) is very scratched and its management is difficult. Becomes very difficult. Therefore, the product is a directional sheet (3a1) (3a2)
Becomes momentum and expensive, one of the factors that increase the manufacturing cost
It was one. Also, the size of the light guide plate (1) is large and small, and it is not possible to prepare various kinds of directional sheets (3a1) (3a2) according to the size of the light guide plate (1). The directional sheet of 1. was formed in advance and cut according to the size of the light guide plate (1).

[0005]

However, the user's demand for cost reduction is becoming more strict, and the present invention satisfies the demand by reducing the costly directional sheet (3a1), and further by reducing the cost of another sheet. In order to reduce the number of directional sheets (3a2), the shape of the ridges (8) `` or the ridges (8 ')''is optically examined, and the groove row (11) is easily formed and the groove row (11) is formed. ) Is hard to be damaged, the yield is high, and further cost reduction can be achieved.

[0006]

[Claim 1] is a general concept of a light guide plate (1) according to the present invention, which is a light incident from a light source (2) arranged on a light incident end surface (S1). Scatters its light output surface
In the light guide plate (1) that emits light from (S2), the light emitting surface (S2)
Alternatively, the reflecting surface (S3) located on the opposite side or the light emitting surface (S
2) and the reflective surface (S3) both ridges (8) or ridges (8 ') or ridges
(8) and the concave stripe (8 ') are formed in parallel and at right angles or incline with respect to the light incident end surface (S1), of the convex or concave stripes (8) (8') adjacent to each other. Pitch (P) is 10μm-600μ
m, and the constituent surface of the ridge (8) or the ridge (8 ') of the light output surface (S2) is finished to be a mirror surface. "

At the light exit surface (S2) of the light guide plate (1) or the reflection surface (S3) located on the opposite side, or both the light exit surface (S2) and the reflection surface (S3) On the other hand, the ridges (8) or the ridges (8 ') formed in the right angle or the inclined direction have a function of guiding the light introduced into the light guide plate (1) to the back of the light guide plate (1). Here, the light emitting surface (S2) or the reflecting surface (S3) means a ridge (8) or a ridge.
If the groove array (11) composed of (8 ') is a sine curve or a cosine curve (the same applies to other waveform curves), it is a plane that passes through the midline of the peaks and valleys (see FIG. 11), In the case of a curve with a plus or minus sign in the absolute value sign, it is a plane that passes through the valley in the ridge (8) (see Fig. 12) and a plane that passes through the mountain in the ridge (8 '). (See FIG. 13). When the flat surface portion (H) is formed between the convex stripes (8) or the concave stripes (8 ′), the flat surface corresponds to the flat surface portion (H). (See Figure 14)

The ridges (8) or the ridges (8 ') have the light guiding function and the light collecting function at the same time. 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). (See Figure 19)

On the other hand, in the case of the concave line (8 '), it is on the diverging side. (Refer to FIG. 20) However, in the case of the concave strip (8 '), the light emitted from the concave strip (8') is changed to the reflected light that reflects the inner surface of the concave strip (8 ') due to its shape, and as a whole, it has a specific shape. The emitted light has a divergence angle. This point will be described in detail. As shown in FIGS. 8 and 20, when the light guide plate (1) is an acrylic resin plate and light is emitted from the recessed section (8 ′) having a semicircular cross section, the light guide plate (1) is Concave line inside
Part (a) of the innumerable luminous flux heading to (8 ') is refracted at the inner peripheral surface of the concave strip (8') to emit light, and this light (b) once goes out to the air layer and becomes concave. It is reflected at the point 0 on the inner surface of (8 '), and this reflected light (C) is emitted by grabbing the edge of the semicircular groove (8'). ), Light (ha) (ha ') << light (ha') emerges symmetrically with respect to the center line (CL) of the concave line (8 '). The light will be emitted within the range (= output angle distribution) indicated by the box, and as a result, it will be condensed. FIG. 8 shows an overall schematic diagram thereof. In addition, FIG. 8 is a groove array composed of convex / concave stripes (8) (8 ').
It is the figure which showed typically the light output angle distribution by (11).

As described above, since the ridge (8) or the ridge (8 ') has a light guiding function and a light collecting function, the ridge (8) or the ridge (8') The same function as the conventional directional sheet (3a1) installed so that the groove array (11) is perpendicular to the light incident end surface (S1), and therefore this directional sheet (3a1) is omitted. Other directional sheet (3a2) `` The groove row (12) of this directional sheet (3a2) is installed in a direction substantially parallel to the light incident end surface (S1) or slightly inclined '' It will be enough. As a result, two directional sheets (3a1) and (3a2), which were required in the past, can be replaced by one sheet (3a2), which enables a significant cost reduction.

Further, the convex stripes (8) or concave stripes (8 ') on the light emitting surface (S2)
By finishing the constituent surface of (1) to a mirror surface state, the scattering of light on the surface of the convex stripes (8) or the concave stripes (8 ′) is suppressed, and the light condensing property is improved.

<Claim 2> is an embodiment of 1-3 of the light guide plate (1) described in “Claim 1”.
(1), the contour line of the sectional shape of the ridge (8) or the ridge (8 ')
(R) is represented by the sine function or the cosine function described in the equations (1) to (4) or the absolute value of the positive and negative values thereof. y = a sin bx …………………… (1) y = ± | a sin bx ｜ ……………… (2) y = a cos bx ……………… (3 ) y = ± | a cos bx | ... (4) where a and b are positive constants, and the range of x is 0 ≦ x ≦ nπ,
n is an integer, y is the direction perpendicular to the light emitting surface (S2), and x is the convex stripe (8)
Alternatively, the direction is parallel to the light exit surface (S2) or the reflection surface (S3) on which the groove (8 ') is formed and is parallel to the light incident end surface (S1).

Here, when a = b = 1, the contour line (R) of the cross section of the convex stripe (8) or the concave stripe (8 ') is a standard sine curve or cosine curve as shown in FIGS. But a
In the case of> 1, b> 1, ridges deeper than those in FIGS.
(8) or the cross section of the groove array (11) of the concave line (8 '). Also, the formula
If an absolute value symbol is added as in (2) and (4), if it is positive,
The negative portion is folded back to be positive, and the shape is continuous as shown in FIGS. On the contrary, in the case of a negative value, the positive part is folded back to be a negative value, and the waveform becomes continuous as shown in FIG.

Here, since the contour line (R) of the cross section of the ridge (8) or the ridge (8 ') is composed of a sine function or a cosine function or their positive or negative absolute values, Excessive light collection on the top (9) of the line (8) or the valley (9 ') of the concave line (8') is mitigated, and the convex line
Light is diffused over the entire area of (8) or the entire circumference of the concave line (8 '), and the development of bright lines is suppressed. Even if the pitch between the convex lines (8) is 100 μm or more (maximum 600 μm), no bright line appears. Therefore, the pitch of the ridges (8) can be made coarser, which facilitates the die production and leads to cost reduction. Incidentally, in general, the height (h) of the crests of the ridges (8) or the depth (h ') of the valleys of the ridges (8') is the width (W) of the base of the ridges (8). Alternatively, the larger the opening width (W ') of the concave line (8'), the stronger the light guiding property. For example, the light guiding property is stronger when the groove (8 ') has a semi-elliptical cross section as shown in FIG. 21 than when it has a semi-elliptical cross section as shown in FIG.

Next, the ridges (8), which are nearly parallel to the light exit surface (S2)
Explaining about the light output method of light that intersects with the concave groove (8 '), the light is the wall portion (8a') constituting the convex stripe (8) or the concave stripe (8 ') next to the air layer. You will pass the part. At that time, it is refracted, and as a result, the light is guided inside the convex strip (8) or the wall (8a ') that constitutes the concave strip (8'), and goes from the light incident end face (S1) to the back. Opposite, the light will be emitted at a certain point on the light emitting surface (S2).
It is difficult to condense the light in all directions in the direction perpendicular to the light output surface (S2) with one ridge (8) or recess (8 ').
A part of the light flux cannot be condensed, but disappears as divergent light << = loss light (15) >>. Such loss light (15)
Is the content of printing on the reflection surface (S3) of the light guide plate (1) (that is, the degree of inclination of the reflection surface (S3) of the light guide plate (1), the white printed dots (6)
Particle size) or the content of the embossed dots in place of the white print dots (6), the light output amount and the light output direction change even for the ridges (8) or the recesses (8 ′) having the same shape. This also applies to the in-conductor diffusion type light guide plate (1). Therefore,
Of the proposed ridges (8) or ridges (8 '), the shape of ridges (8) or ridges (8') should be selected by the light emitting means of the light guide plate (1). You have to choose.

Further, as described above, the ridge (8) or the ridge
(8 ') and a combination of white printed dots (6) and light emitting means such as grain dots, in addition to the groove array (1
Depending on the type and arrangement of other directional sheets (3a2) placed on the light guide plate (1) so that (2) is substantially parallel, the effective output angle of the luminous flux (14) is changed at the same time. Distribution << = diffusion angle
It is indicated by (θ). >> also changes greatly. (Refer to FIG. 8) Generally, when the groove array (11) engraved in the light guide plate (1) is composed of the concave stripes (8 '), the directional sheet (1) placed on the light guide plate (1) ( 3a2) is the ridge (8) facing down (= light exit surface (S2) of the light guide plate (1)
Side), or when the groove array (11) is a ridge (8), the groove array (12) of the upper directional sheet (3a2) is preferably directed upward. Furthermore, regarding the shape of the groove (8 ') forming the groove row (11), by appropriately selecting the groove depth (h') and the opening width (W '),
The total amount of lost light (15) can be reduced.

<Claim 3> is “the light guide plate according to claim 1.
In (1), the top of the cross-sectional shape of the ridge (8) or the ridge (8 ')
(9) or the contour line (R) from the valley (9 ') to the light emitting surface (S2) or the reflecting surface (S3) is a semicircle or a semielliptic curve, a parabola, an error function, a cycloid or an m-order function (m is It is composed of a part of (real number). ”
The light emission theory is basically the same except that the cross-sectional shape of (8 ′) is different from that of the second aspect.

<Claim 4> is another shape of the convex strip (8) or the concave strip (8 ′) formed in the light guide plate (1) (Example 7 and its modification). In the described light guide plate (1),
(8) or the concave line (8 ') constitutes the contour line (R) of the cross-sectional shape, the top (9) of the convex line (8) or the valley (9' of the concave line (8 '). ) From the light emitting surface (S
2) or one of the contour side lines (r1) reaching the reflecting surface (S3) is a semicircle or a semi-ellipse, a parabola, an error function, a cycloid or m
It is a curve formed by a part of a quadratic function (m is a real number), and the other half of the contour side surface line (r2) is the light emitting surface (S2) or the reflecting surface (S2).
It is composed of a straight line that is perpendicular or inclined to 3). (See Figures 23 (a) (b) and 24)

In this case, as shown in FIG. 23 (a), the light guide plate
One contour side line (r1) that passes through the inside of (1) and constitutes the ridge (8)
The light flux heading for is refracted at the interface corresponding to the contour side surface line (r1) formed of a semicircle or the like and emitted. Here, the points (X), (Y) and (Z) that define the ridge (8) will be explained.
Is the top of the contour side line (r1) at the apex of the ridge (8), the point (Z) is the bottom of the contour side line (r1) at the point on the light emitting surface (S2), and the point (X) is the light emitting surface ( The point above S2) is the intersection of the perpendicular from the point (Y) to the light exit surface (S2) and the light exit surface (S2).

Now, assuming that one point (Q1) on the side surface of the contour (r1) is the light emission point, the light flux in all directions reaching the point (Q1) is refracted (perpendicular to the tangent (T) of the point (Q1). The light that coincides with the normal line (M) is emitted in the normal line (M) direction as it is without being refracted.) It will be emitted, but among the emitted light, the adjacent ridges (81)
The light below the apex (Y1) of the "left ridge in the figure" is refracted (the light entering at a right angle is not refracted) and re-enters the adjacent ridge (81). . On the contrary, of the emitted light, the light above the apex (Y1) of the adjacent ridge (81) (shown by the shaded portion) is emitted as it is. This is the apex (Y) of the ridge (8)
Occurs at all points on the contour side surface line (r1) from the bottom point (Z) to the bottom point (Z) and has an angle (light emission angle determined by the material of the light guide plate (1)) with respect to the light emitting surface (S2). The light will come out.

Light is also emitted from the contour side surface line (r2) indicated by the line connecting the point (Y) and the point (X).
(r2) Light from all directions is emitted from the point above,
Light below the tangent line (T2) of the contour side line (r12) of the adjacent ridges (82) enters the ridge (82), and light above the tangent line (T2) exits as it is. As a result, light is emitted at a certain angle with respect to the light emitting surface (S2). Further, when considering the light emission amount of the contour side surface line (r1) and the contour side surface line (r2), the contour side surface line (r1) has a larger area than the contour side surface line (r2) and the light emitting surface (S2 ) Side, the amount of light output is remarkably large.As a result, in the case of the ridge (8), the range mainly indicated by the cross diagonal lines (the material of the light guide plate (1) and the shape of the ridge (8) is It will be emitted at a fixed emission angle).

The same applies to the case of the concave line (8 '), as shown in FIG. 23 (b), the range indicated by the cross hatched lines (the light output angle determined by the material of the light guide plate (1) and the shape of the concave line (8')). ) Will be mainly emitted.

As shown in FIG. 24, the light exit surface of the light guide plate (1)
When symmetrically arranged from the center of (S2), the amount of light going in the direction perpendicular to the light emitting surface (S2) from the light emitting theory increases,
It is particularly effective for improving the brightness of the light emitting surface (S2).

<Claim 5> is still another shape of the convex strip (8) or the concave strip (8 ′) formed in the light guide plate (1) (Example 8 and its modification). In the light guide plate (1) described in (1), adjacent to the top (9) of the ridge (8) or the valley (9 ') of the recess (8') as a boundary, the ridge (8) or the recess ( The two contour side lines (r1) (r2) forming the contour line (R) of the cross-sectional shape of 9 ') are straight lines, and the ridge (8) or the ridge (8') is formed. Inclination angle (Δ) of the contour side lines (r1) (r2) with respect to the light emitting surface (S2) or the reflecting surface (S3)
(γ) are formed so as to be different from each other. ” (See FIGS. 25 and 26)

In this case, the ridge (8) "recess (8 ') not shown"
The contour line (R) of the cross section is an acute-angled, right-angled, or obtuse-angled triangle (not an isosceles triangle), and emits light in a state similar to the case of FIG. In the case of the concave line (8 '), light is emitted in a state similar to that of FIG. Further, similarly to the above, light can be emitted particularly effectively if the light guide plate (1) is arranged symmetrically from the center of the light emitting surface (S2).

<Claim 6> has still another shape of the convex strip (8) or the concave strip (8 ′) formed on the light guide plate (1) (Examples 9 and 10).
Then, "in the light guide plate (1) according to claim 1, the outer surface shape of the ridge (8) or the ridge (8 ') is composed of two or more surfaces."
It is characterized by things. In this embodiment, a quadrilateral cross section is shown. A trapezoidal shape (not shown) is also conceivable. (See FIGS. 27 and 28)

<Claim 7> is still another shape (embodiment 11) of the ridges (8) or the ridges (8 ') formed in the light guide plate (1).
[In the light guide plate (1) according to claim 1, with respect to the cross-sectional shape of the ridge (8) or the ridge (8 '), the light emitting surface on which the ridge (8) or the ridge (8') is formed. (S2) or the reflecting surface (S3) and the side surface of the ridge (8) rising from the boundary between the ridge (8) or the ridge (8 ') or the contour side line (ra) of the recessed ridge (8'). ) (rb) is formed by a straight line, the apex (9) or valley between the contour side (ra) (rb)
(9 ') is formed by a curved line. " (Figure 2
(See 9 (a) (b))

In the case of FIGS. 29 (a) and 29 (b), the contour side surfaces (ra) and (rb) are at right angles to the light exit surface (S2), but of course the invention is not limited to this, and the contour side surfaces (ra) are not limited thereto. ) (rb) may be inclined with respect to the light output surface (S2). In the former case, the profile side (ra) (r
A flat part (H) is formed between b). According to this, since the flat surface portion (H) is formed, the die manufacturing is facilitated. Also, the top (9) or valley between the contour side surfaces (ra) (rb)
Since (9) is formed by a curved line, a bright line does not appear at the top portion (9) or the valley portion (9), and the pitch can be made coarse. Contour side (r
When a) (rb) rises at a right angle to the light emitting surface (S2), the light guiding property of the ridge (8) is increased, and the light emitting angle of the light emitted from the curved top (9) is further increased. It becomes closer to the vertical direction with respect to (S2), and the luminance is improved.

<Claim 8> relates to the combination of the convex stripes (8) and the concave stripes (8 ′) formed on the light guide plate (1), and “the light guide plate (1 according to any one of claims 1 to 7 ), The light output surface (S
2) or the reflective surface (S3) or both the light emitting surface (S2) and the reflective surface (S3) are formed by alternately projecting the ridges (8) or the ridges (8 ')'. (Fig. 14, 31),
It has the property of mixing the features of the ridges (8) and the features of the ridges (8 ').

<Claim 9> refers to the light guide plate according to any one of claims 1 to 8 with respect to the constituent surfaces of the convex stripes (8) and the concave stripes (8 ′).
In (1), the light emitting surface (S2) or the reflecting surface (S3) or the light emitting surface
The top of the ridge (8) formed on both (S2) and the reflecting surface (S3)
(9) Or the valley (9 ') of the groove (8') and its inclined side surfaces (8A) (8A ')
It is composed of irregular and smooth irregular curved surfaces. ” (See FIGS. 32 to 35)

As a method of "cost reduction", which is the greatest problem of the present invention, it is necessary to make the pitch (P) of the concave / convex ridges (8) (8 ') rough to reduce the die manufacturing cost. However, in this case, if the pitch (P) is roughened, a plurality of parallel bright lines appearing at right angles to the light incident end surface (S1) and along the concave-convex stripes (8) (8 ') cannot be used. Particularly when the pitch exceeds 200 μm, a bright line appears. Therefore, there is a limit to the method to reduce the mold manufacturing cost by roughening the pitch (P) of the uneven strips (8) (8 '), so here we improve the mold manufacturing method itself and "cost reduction". It was decided to aim at. As the method, the method described below was adopted.

The convex ridges (8) and concave ridges (8 ') formed by the irregular and smooth uneven curved surface are formed by transferring the shape of the mold cavity surface, so that the shape of the cavity surface is changed. It must be composed of irregular and smooth uneven curved surfaces. Therefore, first, the cavity surface of the mold is scribed by "scribing" to form a large number of parallel scribing grooves (not shown) on the cavity surface. Since the surface of the scribing groove immediately after scribing is sharp, for example, mechanical polishing with an abrasive such as buffing, electrolytic polishing, plating method, chemical etching method eliminates the above "scribing", and the cavity surface The concavo-convex constituting surface is constituted by the irregular and smooth concavo-convex curved surface as described above. Concavities and convexities on the cavity surface can be configured as convex ridges (8) or concave ridges (8 ') by changing the marking method, and the marking groove can be shaped as desired depending on the shape of the marking tool. .

When a transparent resin such as an acrylic resin is molded using this mold, the unevenness having the smooth uneven curved surface is precisely transferred to the acrylic plate, and the top (9) of the ridge (8) is transferred.
Alternatively, the light guide plate (1) is formed in which the valley portion (9 ′) of the concave line (8 ′) and its inclined side surfaces (8A) (8A ′) 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.
The pitch (P) of the marking groove is from 10 μm to 600 μm.
Any one up to μm is selected.

In this case, since the basic shape of the convex stripe (8) or the concave stripe (8 ') is the shape described in any one of claims 1 to 8, the basis of light emission is the basic shape of claim 1. It is the same as the light guide plate (1) described in any one, but since the convex stripes (8) or concave stripes (8 ') are formed in a mirror-like and irregular smooth uneven surface, The light emission direction becomes more random on the entire surface of the convex stripes (8) or the concave stripes (8 '), and as a result, even if the pitch (P) is considerably rough, the light-collecting ability is not significantly impaired and the brightness performance without the appearance of bright lines. A high light guide plate (1) having a high height can be obtained.

When the mold is formed by combining the "scribing method" and the "polishing" as described above, the mold manufacturing cost can be significantly reduced, and the manufacturing cost of the light guide plate (1) can be reduced. Be useful.

<Claim 10> is “the light guide plate (1) according to any one of claims 1 to 9 in which the ridge (8) or the ridge (8 ′) is provided.
Leaving the top (9) or valley (9 ') on the side surface of the convex stripe (8) rising from the boundary between the light emitting surface (S2) or the reflecting surface (S3) or the side surface of the concave stripe (8') descending. The reflective film layer (13) is formed ”. (See FIGS. 15 and 16)

In the light guide plate (1), in order to further improve the luminance efficiency, it is necessary to reduce the loss light as much as possible, and as a method therefor, the portion emitting the loss light (15) is provided with a reflection film layer ( 13), reflect the light (15) that is going to be emitted from this part, change the optical path and return it to the inside of the light guide plate (1), and finally the effective part that does not emit the lost light (15) ( The light was emitted only from the (uncoated portion). Of the coating film layer (13)
In general, (1) is the lower limit of the angle at which the light emitted by refracting from the side surface of the ridge (8) contacts the apex (9) of the adjacent ridge (8). The light emitted by refracting from the side surface of) is within the upper limit of the angle of 45 ° from the center of the ridge (8). When the ridge (8) is a semicircle, it is as shown in FIG. 16 (b). If the angle is less than the angle of contact with the top (9) of the ridge (8), it will re-enter the adjacent ridge (8), so basically the coating film layer (13) of this part Not necessary. In the case of the wedge-shaped light guide plate (1), as shown in FIG. 16 (b), the coating film layer (13) is formed on the side surface of the ridge (8) remote from the light source (2). Good. Of course, it may be provided on both sides as shown in FIG. 16 (a), in which case the range of the coating film layer (13) is as shown in FIG. 16 (b).
A range of (1/4) h to (1/2) h may be provided, or from the bottom
A line passing through (1/2) h or the center of the ridge (8) may be provided in a portion up to 45 ° from the light output surface (S2). When it is provided on both sides, it is particularly effective in the case of a two-lamp type. As a specific example of the coating film layer (13), when the ridge (8) is a semicircle, the coating film layer (1
The height of 3) is the radius (h) of the semicircle = 1/4 to 1/2 of the height. (See Figure 16 (a) (b))

<Claim 11> says, “In the light guide plate (1) according to any one of claims 1 to 10, a light emitting surface (S2) or a reflecting surface (S3) or a light emitting surface (S2) or a reflecting surface (S3). ) Is formed so that the ridges (8) and the ridges (8 ′) formed on both of them are formed so as to intersect with each other ”(see FIGS. 6 and 10). The groove array (11) of () was formed mainly in one direction at a right angle or an angle close to the light incident end surface (S1). And in that case, another directional sheet (3a2)
It is necessary to place the other directional sheet (3a2) on the light emitting surface (S2) so that the groove array (12) of the groove array (12) is substantially perpendicular to the groove array (11). 8) or concave stripes (8 ') or groove rows (11a) (11b) configured by alternately arranging convex stripes (8) and concave stripes (8') are formed so as to intersect with each other. , Light incident end face (S1)
It is possible to simultaneously collect light in parallel and at right angles, and it is possible to eliminate the other directional sheet (3a2). In this case, some divergent light is generated, so the reflective surface
It is necessary to adjust the density of the white printed dots (6) or grain dots of (S3) to the thinner one. Similarly, diffusion type light guide plate in conductor
In (1), it is necessary to reduce the addition concentration of the diffusing agent.

Further, the inclination angle (m) of the intersecting groove rows (11a) (11b) composed of the convex stripes (8) or the concave stripes (8 ') with respect to the light incident end surface (S1).
(n) is generally m = n, but it is desirable to set different values (m ≠ n) in order to avoid the moire phenomenon. In this case, the pattern of the light emitting surface (S2) formed by the intersecting groove rows (11a) (11b) is a diamond pattern.

<< Claim 12 >> is "the light guide plate (1) according to any one of claims 1 to 11
(8 ') and light emitting surface on which the convex stripes (8) or concave stripes (8') are formed
(S2) or the boundary with the reflecting surface (S3) is connected by a curved surface (K) ”(see FIG. 30), whereby the entire light emitting surface (S2) is connected by a curved surface. Since there is no straight line portion, a bright line does not appear in any portion, and the pitch (P) of the ridges (8) or the ridges (8 ′) can be made coarser.

[Claim 13] is a diffusion type light guide plate in a conductor (1)
Regarding the "light guide plate according to any one of claims 1 to 12.
In (1), the light guide plate body (1a) is dispersed with fine particles serving as a light scattering medium to equalize the brightness from the light exit surface (S2).

Here, in order to further enhance the light collecting effect by the groove array (11) of the various convex stripes (8) or concave stripes (8 ′), the light guide plate
When (1) is a diffusion type in the conductor, by doing this, it is possible to have a vertical and horizontal light-collecting effect on the light output surface (S2) and at the same time projecting ridges (8) or recesses (8 ' Even if the pitch in) is made coarser, the appearance of bright lines is small. Especially, the ridge (8) or the ridge (8 ')
The groove rows (11) (11 ') of the light guide plate (1) with the light emitting surface (S2) and the reflecting surface (S3).
When both are provided, a higher light-collecting effect is obtained as compared with the case where they are provided on one surface.

<Claim 14> means that, in the light guide plate (1) according to any one of claims 1 to 13, adjacent ridges (8) are provided.
Or, a flat surface portion that corresponds to both the light emitting surface (S2) or the reflecting surface (S3) or both the light emitting surface (S2) and the reflecting surface (S3) between the concave lines (8 ').
(H) is formed ”.

Theoretically speaking, the luminance performance is higher when there are no flat portions (H) between the ridges (8) or the ridges (8 ') and they are formed in contact with each other, Adjacent ridges
Since the tip of the gap between the (8) or the tip of the side wall between the adjacent recessed strips (8 ') becomes excessively narrow, it is difficult to transfer accurately during molding, and the yield decreases accordingly. It is expensive and easily scratched. By interposing the flat surface portion (H), the above-mentioned difficulty is eliminated, the molding is facilitated, and the cost is reduced.

[Claim 15] is a light emitting surface (S2) and a reflecting surface of the light guide plate (1) according to any one of claims 1 to 14.
(S3) both ridge (8) or groove (8 ') or ridge (8) and groove
(8 ') is a light guide plate (1) formed in parallel with each other, and the convex stripes (8) or concave stripes (8') on the front and back are formed so as to be in a twisted position with respect to each other. ' Characterize.

According to this, a part of the light in the light guide plate (1) is emitted from the reflecting surface (S3) and is reflected by the reflecting sheet (4) arranged along the reflecting surface (S3). It is reflected and immediately returns to the inside of the light guide plate (1). If this point is described in detail, the reflecting surface (S3) has a light-incident end surface.
Since the ridges (8) or the ridges (8 ') are formed diagonally with respect to (S1), a slight air layer is formed between the reflection sheet (4) and the reflection surface (S3) due to the unevenness. Will intervene. Therefore, the light emitted from the reflecting surface (S3) is condensed and emitted by the convex stripes (8) or the concave stripes (8 ') of the reflecting surface (S3). Then, this light is reflected by the reflection sheet (4) and immediately the light guide plate (1).
Return to inside. Here, since the ridges (8) or the ridges (8 ') on the front and back are in a twisted position with respect to each other, the light-collecting direction by the ridges (8) or the ridges (8') of the reflecting surface (S3), This is different from the light-collecting direction of the convex line (8) or concave line (8 ') on the light emitting surface (S2), and as a result, the light on the light emitting surface (S2) is around the perpendicular to the light emitting surface (S2). It will be gathered in, and the light collection effect will be improved. Also, ridges on the front and back
Since (8) or the groove (8 ') is formed, the light guiding property is improved.

[Claim 16] is "the height (h) of the ridge (8) in the light guide plate (1) according to any one of claims 1 to 15.
Alternatively, the depth (h ') of the concave line (8') is formed so as to change with the distance from the light incident end face (S1). '

The light guiding properties of the ridges (8) and the ridges (8 ') are increased as the height (h) of the ridges (8) or the depth (h') of the ridges (8 ') increases. Grow bigger. On the other hand, as the light guide plate (1), its light emitting surface (S2)
It is necessary to obtain a uniform luminance distribution over the entire surface. Therefore, the light output rate is suppressed near the light entrance end surface (S1),
It is necessary to gradually increase the light emission rate as the distance from (S1) increases. Therefore, basically, the height (h) of the ridge (8) or the depth (h ') of the ridge (8') gradually becomes higher or deeper as the distance from the light incident end surface (S1) increases. The light output rate is gradually increased by this, and the light output surface (S
Make the luminance distribution of 2) uniform. Next, in the case of the diffusion type light guide plate in the conductor (1), the reflection of the cathode tube, which is the light source (2), may occur near the light incident end surface (S1). The height of the ridge (8) gradually increases as the distance from (S1) increases.
(h) or the depth (h ') of the recessed line (8') is formed so as to gradually become lower or shallower, and then gradually becomes higher or deeper as it goes away from the light incident end surface (S1) from a place separated to some extent. It is formed so as to become progressively thicker to prevent glare and at the same time gradually increase the light output rate to make the brightness distribution of the light output surface (S2) uniform as a whole.

<Claim 17> means that “the light guide plate (1) according to any one of claims 1 to 13 and claim 16 does not have the convex stripes (8) or the concave stripes (8 ′). Light output surface (S2)
Or, on the reflecting surface (S3), white dots so that its density or area gradually increases as it goes away from the light incident end surface (S1).
(6) Printing or forming embossed dots ”, whereby the luminance from the light emitting surface (S2) can be made uniform.

[Claim 18] relates to a planar illuminator (A) using the light guide plate (1) according to any one of claims 1 to 17, and relates to "the guide according to any one of claims 1 to 18". Light board (1)
A light source (2) disposed along the light incident end surface (S1) provided at least at one end of the light guide plate (1), and a light source (2) disposed behind the light source (2). )) A reflector (7) for condensing light from the light incident end surface (S1), a diffusion sheet (3b) arranged on the light exit surface (S2) of the light guide plate (1) and its groove array (12). Is the light guide plate
One directional sheet (3a2) arranged on the light emitting surface (S2) at substantially right angles to the groove array (11) of (1) and the light emitting surface of the light guide plate (1) A reflection sheet (4) arranged along the reflection surface (S3) on the side opposite to (S2), and a light reflection end surface of the light guide plate (1).
(S4) and the end face reflection tape (5) ”. Here, if the groove array of the light guide plate (1) is in one direction, the directional sheet (3a2) is necessary, and the groove array (12) of the directional sheet (3a2) is the groove array of the light guide plate (1) ( The light exit surface of the light guide plate (1)
It is not always necessary when the groove rows (11a) and (11b) are provided so as to intersect (S2). Therefore, in this case, the diffusion sheet
Only (3b) is laid on the light output surface (S2).

[0051]

EXAMPLES Hereinafter, an example of a light guide plate (1) having a basic shape of the present invention and a planar illuminator (A) using the light guide plate (1) will be described. As shown in FIG. 1, the light guide plate (1) has a wide light incident end surface (S1) on which the light source (2) is arranged.
The light-reflecting end surface (S4) on the opposite side of (S1) is formed narrow, and the reflecting surface (S3) with respect to the light emitting surface (S2) between both end surfaces (S1) and (S4).
Is formed to be inclined, and its cross section is formed to have a wedge shape. (Note that the light guide plate (1)
Since the side surface between the light incident end surface (S1) and the light reflection end surface (S4) also reflects light here, it is also shown as (S4), but the end surface reflection tape (5) is not necessarily provided on the side surface portion. Good. )
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, conversely, use one in which the light exit surface (S2) is inclined with respect to the light entrance end surface (S1) and the reflection surface (S3) is perpendicular to the light entrance end surface (S1). It goes without saying that it is okay. As a material, an acrylic plate having excellent light transmission is generally used.

A white printed dot (6) or a grain is provided on the reflection surface (S3), and the light exit surface (S2) is further provided on the light exit surface (S2).
The rows of ridges (8) are formed so as to be orthogonal or inclined to 1). The ridges (8) are composed of various curved surfaces described later, and the pitch (P) between the ridges (8) is 10 μm to 60 μm.
It is 0 μm, and its surface is a mirror surface state. The included angle between the ridge (8) and the light incident end surface (S1) is 70 ° to 90 °. Ridge
The contour line (R) of the cross section of (8) is a curve represented by, for example, a semi-circular arc or a semi-ellipse, a sine function, a cosine function, a parabola or an error function, a cycloid, and a m-th order function (m is a real number). . From the standpoint of ease of mold making, a circular arc is preferable, but from the viewpoint of light converging ability, a sine function, parabola, ellipse or error function 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. Furthermore, a reflection sheet (4) is installed below the reflection surface (S3) of the wedge-shaped light guide plate (1), and
On top of 2), one directional sheet (3a2) and, if necessary, one scattering sheet (3b) are installed. Directional sheet
A large number of groove rows (12) are formed in parallel in (3a2), and the groove rows (12) are installed so as to be parallel or slightly inclined to the light incident end surface (S1) of the wedge-shaped light guide plate (1). It That is, generally, the ridge (8) formed on the light exit surface (S2) of the wedge-shaped light guide plate (1) is the light entrance end surface.
When it is perpendicular to (S1), in order to prevent the occurrence of the moire phenomenon, the directional sheet (3a2) has its groove row (12) with respect to the light incident end surface (S1) of the wedge-shaped light guide plate (1). When the convex stripes (8) formed on the light exit surface (S2) of the wedge-shaped light guide plate (1) are arranged so as to be slightly inclined, and are formed to be inclined with respect to the light incident end surface (S1). The directional sheet (3a2) is arranged such that its groove array (12) is parallel to the light incident end surface (S1) of the wedge-shaped light guide plate (1). Of course, when the ridge (8) is perpendicular to the light incident end surface (S1), the groove array (12) of the directional sheet (3a2) becomes parallel to the light incident end surface (S1) of the wedge-shaped light guide plate (1). Or the ridges (8)
The groove array (12) may be arranged so as to be inclined with respect to the light incident end surface (S1) of the wedge-shaped light guide plate (1) when inclined with respect to 1).

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 incident light travels straight in the wedge-shaped light guide plate (1), and most of the light is reflected by the reflection surface (S3) or the reflection sheet (4), its course is changed, and countless reflections are repeated. Most of the light is emitted from the light emitting surface (S2). Part of the light that is incident substantially parallel to the light emitting surface (S2) or the reflecting surface (S3) is reflected on the reflecting surface (S3).
It is reflected by the end face reflection tape (5) arranged on the light reflection end face (S4) without being reflected by the light reflection end face (S1), and is reflected again by the reflector (7). The course has changed, and the light is finally coming out.

Here, since the ridge (8) is formed so as to be inclined at a right angle or at an included angle n (70 ° to 90 °) with respect to the light incident end surface (S1), the ridge (8) is formed. The light introduced into the light guide plate (1) is guided to the back of the light guide plate (1), and the light reflection end surface
Reach (S4). At the same time, of the light emitted from the light exit surface (S2), the light exit angle distribution in the direction parallel to the light entrance end surface (S1) is displayed.
Focus in a direction perpendicular to (S2). Here, since the contour line (R) of the constituent surface of the ridge (8) is formed by a curved line selected from the various curved lines, excessive condensing on the apex (9) is alleviated. Light is diffused over the entire top portion (9), and the development of bright lines is suppressed, so that the pitch of the ridges (8) can be made coarser.

Subsequently, since the groove array (12) of the directional sheet (3a2) installed on the ridge (8) is installed so as to be substantially parallel to the light incident end surface (S1), , Here, the light output angle distribution in the direction perpendicular to the light incident end surface (S1) is condensed 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). When the condensed light is too sharp, the diffusion sheet (3b) is installed on the directional sheet (3a2), and the diffusion sheet (3b) diffuses the light uniformly, and as a result, the light emitting surface (S2 ) Will be emitted uniformly and with high brightness. Directional sheet
The groove array (12) of (3a2), if purchased, has a cross-sectional shape of a right angle or a simple isosceles triangle, but the profile of the cross section at the top (9) of the groove array (12) of the directional sheet (3a2). When the line is formed in a curved shape, too, the excessive condensing on the apex (9) is alleviated, and the light is diffused over the entire apex (9), so that the development of the bright line is suppressed. The degree is eased and the diffusion sheet (3b)
Can be omitted.

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 one-lamp type parallel plate type (not shown) or 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.

When the ridges (8) are formed on both surfaces of the light guide plate (1) as shown in FIG. 2, the upper and lower ridges (8) are in "twisted positions" with each other. ), The white print dots (6) or the embossed dots are provided only on the reflection surface (S3) side and on the light output surface (S2) side, the concave stripes (8 ') are the same as the above instead of the convex stripes (8). In some cases, one or both of the light guide plates (1) may be provided.
In addition, the ridges (8) and the ridges (8 ') may be alternately formed, or the flat portion (H) is formed between the ridges (8) and the ridges (8'). There are cases, etc. In addition, a reflective coating layer on a part of the ridge (8)
There is a case where (13) is formed and the loss light (15) is cut. In addition, the ridges (8) and the ridges (8 ') are formed by intersecting the same surface of the light guide plate (1) << light emitting surface (S2) or reflection surface (S3) >>, and a directional sheet (3a1) ( Both 3a2) may be omitted. In the case where the ridges (8) and the ridges (8 ') are formed so as to intersect with each other, the height of one ridge (8) or the depth of the ridge (8') corresponds to the other ridge ( The height of 8) or the depth of the groove (8 ') may be changed. Thereby, the light guiding property is improved as compared with the case where the height or the depth is the same.

(Embodiment 1) In a 1-lamp wedge-shaped light guide plate (1) having a width of 10.4 ", a pitch of 250 μm is formed on its light emitting surface (S2).
A groove array (11) of ridges (8) having a semi-elliptical cross section was formed at a right angle to the light incident end surface (S1), and shibo dots were formed on the reflecting surface (S3) instead of the white printed dots (6). The processing density of the embossed dots (6) was formed so as to become denser as the distance from the light incident end surface (S1) increased, and the brightness distribution of the light emitting surface (S2) was made uniform. Further, on the light exit surface (S2), the other row of directional sheets << the top manufactured by Mitsubishi Rayon Co., with the groove row (12) parallel to the light entrance end surface (S1) and with the top (9) facing up. Angle 90 ° Brand name BEF 90 >> (3a2) is installed, the diffusion sheet (3b) is further arranged thereon, and the reflection sheet (4) is arranged along the reflection surface (S3).
An end face reflection tape (5) << Rivic tape (trade name) >> was arranged on the light reflection end face (S4) to form a backlight device (A). When the luminance performance of the backlight device (A) thus formed was measured, it was an average luminance of 1,650 cd / m ² and the surface type illumination body (A) of soft light in which no bright line was observed
It became.

(Comparative Example) On the contrary, the same grain dots
Use the light guide plate (1 ') of (6) whose light exit surface (S2') is flat. On the flat light exit surface (S2 '), two directional sheets << Mitsubishi Rayon Co., Ltd. Angle 90 ° Brand name BEF 90 >> (3a1) (3a2) was laid. One directional sheet (3a
The groove array (11) of 1) was arranged at right angles to the light incident end surface (S1), and the groove array (12) of the other directional sheet (3a2) was arranged in parallel. The other parts have the same arrangement as that of the first embodiment. << This is the conventional standard type. >> When the luminance performance of this standard type backlight device (B) was examined, it was 1,670 cd / m ² . Comparing Example 1 with the comparative example, by processing the ridges (8) on the light output surface (S2), the directional sheet (3a1) of the directional sheet (3a1) has the same brightness performance. It was possible to reduce the number of sheets, and it was possible to achieve a significant cost reduction.

(Embodiment 2) The reflection surface (S3) of the one-lamp wedge-shaped light guide plate (1) having an area of 10.4 "is made to have a high density (the distance from the light incident end surface (S1) increases the density). The white printed dots (6) are provided to make the brightness distribution uniform and the pitch of 30 on the light emitting surface (S2).
A comb-teeth-shaped groove array (11) composed of a convex strip (8) having a rectangular cross section with a size of 0 μm was formed at a right angle to the light incident end surface (S1). On the die side, a groove array (11) composed of rectangular recesses having a rectangular cross section is formed on the cavity surface by a scribing method, and the comb tooth-shaped groove array (1) is formed.
The cavity surface of the mold (not shown) for forming the light guide plate (1) was electrolytically polished so that the corner portion of 1) had a roundness, so that the irregularities on the cavity surface had a roundness. As a result, the ridge (8) of the light guide plate (1) has a rectangular cross section and its surface is irregular and has a smooth mirror-like curved surface. In addition, another directional sheet << BEF90 brand name 90 ° vertical angle Sumitomo 3M company >> (3a2) so that it is parallel to the light incident end surface (S1) and the top part (9) faces upward The backlight device (A) was constructed by arranging them. "A revic tape (trade name), a reflector, and a diffusion sheet are also incorporated as an end face reflection tape. When the luminance performance of the backlight device (A) thus formed was measured, it was 1,620 cd / m ² , and although the one directional sheet (3a1) was reduced, the comparative example And the luminance performance were almost the same.

(Embodiment 3) Pitch 3 is set between the light emitting surface (S2) and the reflecting surface (S3) of the 1-lamp wedge-shaped in-conductor light guide plate (1) having an area of 10.4 ".
The surface of the concave line (8 ′) “the concave line (8 ′)” having a parabolic cross section of 50 μm is composed of a smooth and irregular curved surface having a mirror surface. The groove arrays (11) and (11 ′) of “” were formed at right angles to the light incident end surface (S1). Further, another directional sheet << BEF90 (trade name: BEF90, 90 ° vertical angle, manufactured by Sumitomo 3M Co., Ltd.) >> (3a2) is arranged so as to be parallel to the light incident end surface (S1) to form a backlight device (A). "A revic tape (trade name), a reflector, and a diffusion sheet are also incorporated as an end face reflection tape. The luminance performance of the backlight device (A) thus formed was measured and found to be 1,710 cd / m ² . By processing the light guide plate (1) with the concave line (8 ') having a parabolic cross section, a higher brightness than the comparative example (conventional standard product) can be obtained, and one directional sheet (3a1) can be obtained. We were able to reduce the cost and achieve cost reduction. Furthermore, in this case, the "reflection phenomenon" of the cold cathode tube (2), which appears on the light emitting surface (S2) near the cold cathode tube (2) which is the light source (2), has been completely eliminated. In this case as well, "electrolytic polishing" was applied to the cavity surface in order to make the surface of the groove array formed in the cavity surface by the scribing method round.

(Embodiment 4) A mold for forming a wedge-shaped in-conductor light guide plate (1) having an area of 10.4 ", a cavity surface to be a light emitting surface (S2) having a pitch of 250 μm and an apex angle of 90 °. A V-notch strip is machined by scribing, and then the cavity surface of this mold is electrolytically polished to completely eliminate the "flickering" by scribing and have a smooth top and bottom (9) This was combined with a metal mold (not shown) having a textured surface on the reflection surface side, and resin molding was performed for 10.4 ″.
The wedge-shaped in-conductor light guide plate (1) was formed. The ridges (8) of the light guide plate (1) thus formed are composed of irregular and smooth irregular curved surfaces. On the light emitting surface (S2) of the light guide plate (1), the directional sheet (3a2) having an apex angle of 68 ° is arranged so that the groove rows (11) and (12) are orthogonal to each other so that the apex portion (9) faces downward. The backlight device (A) was constructed by mounting and incorporating various parts (3b) ... The luminance performance of the backlight device (A) thus formed was measured and found to be 1,610 cd / m ²
And the average brightness almost equal to that of the standard type shown in the comparative example was obtained. Therefore, also in this case, the directional sheet (3a1)
I was able to reduce the cost by reducing one of the above. At the same time, the machining cost was very simple by the marking method, and the die cost could be greatly reduced.

(Embodiment 5) A groove of a convex strip (8) having a semi-circular cross section at a right angle to the light incident end surface (S1) of a light guide plate (1) with a print-less wedge-shaped conductor having a width of 10.4 ". Forming rows (11) and said ridges (8)
A flat portion (H) having a diameter of ¼ of the ridge (8) was provided between them. Then, on the side surface of the ridge (8), 1/4 to the radius (h) of the ridge (8)
It was coated with a specular reflector with a width of 1/2. (The regular reflection agent means, for example, an aluminum vapor-deposited film.) The light guide surface (S2) of the light guide plate (1) is provided with the ridges (8) on top of another directional sheet << BEF90 brand name 90 ° vertical angle. Sumitomo 3M '' (3a2)
Was mounted, and various parts (3b) were incorporated in the same manner as described above to form a backlight device (A). As a result of measuring the luminance performance of the backlight device (A) thus formed,
The average luminance was 60 cd / m ² , and an average luminance almost equal to that of the standard type shown in the comparative example was obtained. Therefore, in this case as well, one sheet of the directional sheet (3a1) could be reduced and the cost could be reduced.

(Embodiment 6) An uneven V notch is formed by intersecting the cavity surface for forming the light output surface (S2) and the inverted V notch is formed by electropolishing in an irregular and smooth curve. A printing-less wedge-shaped in-conductor light guide plate (1) having a width of 10.4 "was formed by a holding mold. The V notch was located at 75 ° from the left and 80 ° from the right with respect to the light incident end face (S1). It is formed so as to be inclined.The grain dots formed on the reflecting surface (S3)
The external shape of (6) includes those obtained by cutting out a part of a sphere or a rugby ball, those having a polygonal pyramid shape such as a triangular pyramid and a quadrangular pyramid, and those having a polygonal column shape such as a columnar shape or a prismatic shape. The projected shape is formed to be a star shape or other irregular shape, and its typical diameter is 250 μm to 5 μm, which is so small that it cannot be visually recognized. In the above case, the projected shape of a sphere is circular, the shape of a rugby ball is an ellipse, the shape of a triangular pyramid or a quadrangular pyramid is a triangle, a square, a rhombus, a parallelogram, a trapezoid, a pentagon ... Other polygons. There are first and second methods for the distribution of microscopic grain dots (6), and the first method is as follows. The entire processed surface (= reflective surface (S3)) is evenly divided (for example, to 1 cm ² ), and the number of grain dots (6) for each divided block (= predetermined area unit) on the processed surface is This is a case where it is formed so as to increase gradually as it is separated from the cathode tube (2). Grain dots in each block
(6) will be evenly distributed. Therefore, in this case, the dot addition area ratio gradually increases for each block. ☆ The second method is grained on the machined surface (6)
This is a case where the intervals are formed so as to become gradually shorter as the distance from the cathode tube (2) increases. That is, the distance in the vertical axis direction (direction perpendicular to the light-incident end surface (S1)) between the adjacent embossed dots (6) gradually changes, and the density of the embossed dots (6) gradually increases as a whole. is there. The outer shape and distribution of the embossed dots (6) formed on the reflection surface (S3) are as described above.Furthermore, the light guide surface (S2) of the light guide plate (1) has the ridge (8) on the other side. Directional sheet << BEF90 brand name 90 ° vertical angle
Sumitomo 3M Co., Ltd. >> (3a2) was placed, and various parts (3b) ... When the luminance performance of the backlight device (A) thus formed was measured, it was 1,590 cd / m ² , and an average luminance close to that of the standard type shown in Comparative Example was obtained. Therefore, in this case, two sheets of the directional sheets (3a1) and (3a2) could be eliminated, and further cost reduction could be achieved.

[0066]

As described above, since the light emitting surface of the light guide plate of the present invention is provided with a groove array of convex stripes which are orthogonal or inclined with respect to the light incident end face, the light guide plate is provided inside the light guide plate. The introduced light will be guided to the back of the light guide plate, and it is possible to omit the conventional directional sheet for laying the lower side, which is installed so that the groove rows are in a direction perpendicular to the light incident end surface. Then, it is sufficient to simply use another directional sheet, "the groove array of this directional sheet is installed so as to be in a direction substantially parallel to the light incident end face", and it is possible to greatly reduce the cost. Further, by forming the convex stripes or the concave stripes so as to intersect with each other, it is possible to eliminate the two directional sheets, and it is possible to further reduce the cost. In addition, when manufacturing the mold, by forming concave and convex stripes with a predetermined cross section on the cavity surface by scribing, and then performing electrolytic polishing, the convex stripes formed by smooth and continuous concave and convex curved surfaces. Alternatively, a groove array in which concave stripes or convex stripes and concave stripes are alternately formed can be easily formed on the cavity surface, and the die manufacturing cost can be significantly reduced. In addition, since the ridges and ridges are composed of curved surfaces, excessive light condensing on the tops and valleys is mitigated, light is diffused throughout, and the development of bright lines is suppressed. It is possible to make the pitch of the convex stripes or the concave stripes coarser, which also facilitates the die manufacturing, leading to cost reduction. Further, by blocking a part of the side surface of the ridge, loss light can be blocked and converted into effective light, and brightness can be improved.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a second embodiment of the planar illuminator according to the present invention.

FIG. 3 is a perspective view of a third embodiment of the planar illuminator according to the present invention.

FIG. 4 is a perspective view of a fourth embodiment of the planar illuminator according to the present invention.

FIG. 5 is a perspective view of a surface illuminating body according to a fifth embodiment of the present invention.

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

FIG. 7 is a schematic sectional view of FIG.

FIG. 8 is a side view seen from the light source side of FIG.

9 is a plan view of FIG.

10 is a plan view of FIG.

FIG. 11 is a partial perspective view when the cross-sectional shape of the ridge according to the present invention is a sine or cosine curve.

FIG. 12 is a partial perspective view when the cross-sectional shape of the ridge according to the present invention is a positive absolute value of a sine or cosine curve.

FIG. 13 is a partial perspective view when the cross-sectional shape of the ridge according to the present invention is a negative absolute value of a sine or cosine curve.

FIG. 14 is a partial perspective view of the present invention in which convex stripes and concave stripes are alternately arranged, and a flat surface portion is formed between the convex stripes and the concave stripes.

FIG. 15 is a partial perspective view of the present invention in which a flat surface portion is provided between the ridges.

FIG. 16 (a) = Partial perspective view in the case where a flat surface portion is arranged between the convex stripes of the present invention and a reflective coating layer is formed on both side surfaces of the convex stripes. (B) = The convex projection of the present invention Partial perspective view when a flat surface portion is arranged between the strips and a reflective coating layer is formed on one side surface of the convex strip.

FIG. 17 is a partial perspective view of the present invention in which a flat portion is provided between the concave lines.

FIG. 18 is a partial front view when the cross-sectional shape of the ridge of the present invention is a sine or cosine curve.

FIG. 19 is a partial front view when the cross-sectional shape of the ridge according to the present invention is a positive absolute value of a sine or cosine curve.

FIG. 20 is a partially enlarged front view showing a path of a light beam when light is emitted from a groove having a parabolic section according to the present invention.

FIG. 21 is a partially enlarged front view showing a path of a light beam when light is emitted from a groove having a semicircular cross section according to the present invention.

FIG. 22 is a partially enlarged front view showing the path of a light beam when a concave strip having a semi-elliptical cross section according to the present invention emits light.

[Fig. 23] (a) = Partially enlarged front view showing the emission state of a convex strip having a 1/4 arc cross section. (B) = Partial enlargement showing the emission state of a concave strip having a 1/4 arc cross section. Front view

FIG. 24 is a front view of a light guide plate according to the present invention in which a ridge having a 1/4 arc cross section is symmetrically arranged from the center of the light guide plate.

FIG. 25 is a partially enlarged front view of the present invention in which the cross-sectional shape of the ridge is an obtuse triangular saw blade shape.

FIG. 26 is a partially enlarged front view of the present invention in which the ridge has a sawtooth shape with an acute-angled triangle.

FIG. 27 is a partially enlarged front view of the ridge of the present invention having a quadrilateral cross-sectional shape.

FIG. 28 is a partially enlarged front view of the ridge of the present invention having a rectangular or square cross-sectional shape.

FIG. 29 (a) = Partially enlarged front view when the cross-sectional shape of the ridge of the present invention is comb-teeth-shaped. (B) = Partial enlargement when the cross-sectional shape of the ridge of the present invention is comb-teeth. Front view

FIG. 30 is a partially enlarged front view of the present invention in which a flat surface portion is provided between the recessed stripes and a boundary between the recessed stripes and the flat surface portion is formed by a curved surface.

FIG. 31 is a partially enlarged front view of the present invention in which the convex stripes and the concave stripes are alternately formed and a flat surface portion is formed between the convex stripes and the concave stripes.

FIG. 32 is a partially enlarged perspective view of a ridge before polishing according to the present invention.

FIG. 33 is a partially enlarged perspective view of a ridge after polishing according to the present invention.

FIG. 34 is a partially enlarged perspective view of a groove before polishing of the present invention.

FIG. 35 is a partially enlarged perspective view of the groove after polishing according to the present invention.

FIG. 36 is a perspective view of a conventional example.

[Explanation of symbols]

 (1) ... Light guide plate (2) ... Light source (6) ... White printed dots or grain dots (8) ... Convex line (8 ') ... Recessed line (9) ... Top part (9') ... Valley part (R) ... Contour Line (S1)… Incoming light end face (S2)… Emitting surface (S3)… Reflecting surface (S4)… Light reflecting end face

[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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Juno Nakahashi 2465-94 Iioka, Saijo City, Ehime Prefecture (72) Inventor Yusumi Taguchi 3-6 Masamie-cho, Niihama City, Ehime Prefecture (72) Inventor Tomihisa Watanabe Ehime Prefecture 3-4-52 Hongo, Niihama-shi

Claims (18)

[Claims] 1. A light guide plate that scatters light incident from a light source disposed on a light incident end surface and emits the light from the light emitting surface, or a light emitting surface or a reflecting surface located on the opposite side or the light emitting surface. The convex stripes or the concave stripes or the convex stripes and the concave stripes are formed on both the reflection surface and the reflection surface so as to be parallel to each other and at a right angle or an inclination with respect to the light incident end surface, and the pitch of the adjacent stripes is 10 μm to 600 μm. A light guide plate having a convex surface or a concave surface on the light emitting surface, which is finished to be a mirror surface. 2. The light guide plate according to claim 1, wherein the contour line of the convex or concave sectional shape is expressed by any of the sine function or the cosine function described in formulas (1) to (4). A light guide plate characterized by being performed. y = a sin bx …………………… (1) y = ± | a sin bx ｜ ……………… (2) y = a cos bx ……………… (3 ) y = ± | a cos bx | ... (4) where a and b are positive constants, and the range of x is 0 ≦ x ≦ nπ,
n is an integer, y is a direction perpendicular to the light exit surface, and x is a direction that coincides with the light exit surface or the reflection surface on which the convex stripe or the concave stripe is formed and is parallel to the light incident end surface. 3. The light guide plate according to claim 1, wherein the contour line of the convex or concave cross-sectional shape is a semicircle or a semi-ellipse, a parabola, an error function, a cycloid, or an m-order function (m is a real number). A light guide plate characterized by being configured by a curved line that is partially represented. 4. The light guide plate according to claim 1, wherein a contour line of a cross-sectional shape of a convex line or a concave line is formed, and the convex line or the concave line is formed from a top of the convex line or a valley of the concave line. One of the contour side lines reaching the light emitting surface or the reflecting surface on which the stripe is formed is a curve formed by a part of a semicircle or a semiellipse, a parabola, an error function, a cycloid or an mth-order function (m is a real number). The light guide plate is characterized in that the other half of the contour side surface line is constituted by a straight line perpendicular or inclined to the light emitting surface or the reflecting surface. 5. The light guide plate according to claim 1, wherein two contours that are adjacent to each other with a top of the ridge or a valley of the ridge as a boundary and that form a contour line of a cross-sectional shape of the ridge or the ridge. A light guide plate, wherein the side lines are straight lines, and the inclination angles of the contour side lines with respect to the light emitting surface or the reflecting surface on which the convex or concave lines are formed are different from each other. 6. The light guide plate according to claim 1, wherein the outer shape of the convex stripe or the concave stripe is composed of two or more surfaces. 7. The light guide plate according to claim 1, wherein, regarding the cross-sectional shape of the ridge or the ridge, the boundary between the light emitting surface or the reflection surface on which the ridge or the ridge is formed and the ridge or the ridge. 1. A light guide plate, characterized in that a side surface of a convex strip rising from the above or a concave side surface of a concave strip is formed by a straight line, and a top portion or a valley portion between the contour side surfaces is formed by a curved line. 8. The light guide plate according to claim 1, wherein a convex line or a concave line is alternately and repeatedly formed on the light emitting surface or the reflecting surface or both the light emitting surface and the reflecting surface. A light guide plate that features things. 9. The light guide plate according to any one of claims 1 to 8, wherein the projection tops or recess troughs formed on the light exit surface or the reflection surface or both the light exit surface and the reflection surface, and the slopes thereof. A light guide plate whose side surface is irregular and has a smooth uneven curved surface. 10. The light guide plate according to any one of claims 1 to 9, wherein a top portion is formed on a side surface of the ridge rising from a boundary between the ridge or recess and the light emitting surface or the reflecting surface, or on a side surface of the ridge falling. A light guide plate, characterized in that a reflective film layer is formed on the entire side surface or a part of the side surface, leaving a valley portion. 11. The light guide plate according to claim 1, wherein a convex line or a concave line or a convex line and a concave line formed on both the light emitting surface or the reflecting surface or the light emitting surface or the reflecting surface. A light guide plate characterized in that a set of strips are formed so as to intersect with each other. 12. The light guide plate according to any one of claims 1 to 11, wherein the boundary between the convex strip or the concave strip and the light emitting surface or the reflecting surface on which the convex strip or the concave strip is formed is connected by a curved surface. The light guide plate that is characterized. 13. The light guide plate according to any one of claims 1 to 13, wherein fine particles to be a light scattering medium are dispersed in the light guide plate body to equalize the brightness from the light exit surface. Light guide plate. 14. The light guide plate according to any one of claims 1 to 13, wherein a flat surface portion is provided between the adjacent convex stripes or concave stripes, and the light exit surface or the reflective surface or both the light exit surface and the reflective surface respectively. A light guide plate characterized by being formed. 15. A light guide plate according to any one of claims 1 to 14, wherein a convex line or a concave line or a convex line and a concave line are formed in parallel on both the light emitting surface and the reflecting surface. The light guide plate is characterized in that the convex stripes or concave stripes on the front and back sides are formed so as to be twisted with respect to each other. 16. The light guide plate according to claim 1, wherein the height of the convex stripes or the depth of the concave stripes is formed so as to change as the distance from the light incident end surface increases. And a light guide plate. 17. The method according to any one of claims 1 to 13 and claim 16.
In the light guide plate according to any one of the above, on the light emitting surface or the reflecting surface on which the convex stripes or the concave stripes are not formed, white printed dots or grain dots so that the density or area thereof gradually increases as the distance from the light incident end surface increases. The light guide plate is characterized in that the brightness from the light emitting surface is made uniform by forming the. 18. A light guide plate according to claim 1, a light source provided along at least one end face of the light guide plate, and a light source provided behind the light source. The reflector for condensing the light from the light source on the light incident end surface, the diffusion sheet arranged on the light emitting surface of the light guide plate, and the groove array thereof are substantially perpendicular to the groove array of the light guide plate. One directional sheet disposed as necessary on the above, a reflection sheet disposed along the reflection surface opposite to the light exit surface of the light guide plate, and a light reflection end surface of the light guide plate. A surface-type lighting body characterized by being configured with an end face reflection tape provided.