JP2001093320A - Surface light source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the constraint of an combination of an edge line type surface light source unit integrated with a LED as a light source and a mother substrate and provide more resistance to static electricity of the LED. SOLUTION: An edge light type surface light source unit 10 comprises a light guide member 1 having at least one through-hole 8 or blind hole for refracting or reflecting an emitted light from a light source and reflecting parts 6 provided at both sides of a portion opposed to a LED 2 on the side face of the light guide member. The LED 2 is connected to a capacitor (not illustrated) for preventing its destruction and an adjusting resistance and mounted on a LED substrate 13 and the LED substrate 13 is joined to a side face 12c opposed to the through-hole 8 or the blind hole in the light guide member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar light source unit of a display device having a backlight mechanism for illuminating a transmissive or transflective panel from the back.

[0002]

2. Description of the Related Art In recent years, book-type word processors and computers, portable telephones, small-sized portable telephones such as portable TVs, and the like.
2. Description of the Related Art As a display device of a thin information device, a liquid crystal display device having a thin and easy-to-see backlight mechanism is used. As such a backlight mechanism, a planar light source that irradiates the liquid crystal panel from behind to the entire surface is used. As the planar light source, a fluorescent lamp, which is a linear light emitting source, and a luminous flux of the liquid crystal panel are used. In general, a light guide plate that converts light into a planar light beam to be irradiated has been used.
Plural LEDs (light emitting diodes) instead of fluorescent lamps as linear light sources for the purpose of further thinning and longer life
Are arranged in a line.

FIG. 8 and FIG. 9 are views showing a surface light source unit for an edge light type panel having an LED (light emitting diode) array light source as an example of such a conventional backlight mechanism. FIG. 9 is a perspective view and FIG. 8 and 9, reference numeral 110 denotes a planar light source unit, which has a light guide member 101 and a plurality of LEDs 102 arranged linearly as a light source. A plurality of incident portions 105 forming an arc-shaped escape portion are provided on one side surface 101d of the light guide member 101. Here, a plurality of L
The ED 102 is mounted on an LED substrate 108, and the LED substrate 108
2 is positioned and joined to the side surface 101d.

[0006] Reference numeral 106 denotes a mother board. Reference numeral 109 denotes a lead wire connecting the mother board 106 and the LED 102 on the LED board 108. The drive circuit (not shown) disposed on the circuit board 106 is connected to the LED 102 via the lead wire 109 to conduct.

The light guide member 101 is a plate made of a transparent member such as a transparent plastic material and has a substantially rectangular parallelepiped shape.
01b, a light diffusing surface 101a such as a plurality of minute embosses or a plurality of hemispherical dots is provided on the surface as a means for reflecting light from the light source toward the opposing light emitting surface. Are formed.

Further, a reflection plate 103 such as a white sheet is provided near the light diffusion surface 101a. The light emitted from the LED 102 enters the light guide 101, and most of the light undergoes total reflection on the upper surface (light emitting surface) 101b, total reflection on the lower surface, or scattering by the light diffusing surface 101a such as grain or hemispherical dot once. Alternatively, the light is emitted from the upper surface to the outside after performing a plurality of times. At this time, a part of the light is transmitted through the lower surface and enters the reflection plate 103. However, the light is reflected here and enters the light guide member 101 again, and is emitted from the upper surface to the outside directly or after being reflected. The light emitted to the outside passes through the liquid crystal panel 107 to illuminate. In order to ensure the uniformity of the luminance in the surface to be illuminated, the roughness of the grain in the lower surface is adjusted, and the shape and density of the hemispherical dots are changed depending on the location.

[0007]

However, the above-mentioned planar light source unit has the following problems. One of them is that when a point light source such as an LED is used as a light source, many light sources are required. This is due to the directivity of the LED. If there is only one LED, the intensity of light emission varies greatly depending on the direction.
There is a limit even if the shape and density of the hemispherical dots are changed depending on the location to make the luminance of the illumination light uniform. Therefore, there is a problem that a large number of LEDs are required, resulting in an increase in cost and an increase in current consumption.

Another problem is that, due to the structure of the planar light source unit, it is necessary to arrange the LEDs on the side surfaces of the plate-like light guide member. For this purpose, as shown in FIG. It is necessary to arrange the LED board 108 on the side face via an LED board 108 independent of the board 106, and therefore, the LED board 108 must be electrically connected to the mother board 106. At this time, the voltage to be applied to the LED must be supplied as an output voltage from the motherboard 106. In applying a predetermined voltage value to the LED, the combination with the motherboard is restricted, that is, the LED and the This limits the combination of the integrated planar light source and the motherboard. In addition, there is a problem in that the LEDs are independently present in the structure, and are easily destroyed by static electricity.

An object of the present invention is to improve the above-mentioned problems in the prior art. The present invention solves the above-described problem, and enables one or a small number of LEDs close to a point light source to be used as a light source in an edge light type planar light source unit to emit a uniform planar light flux. And LE
Another object is to improve the combination of the planar light source integrated with D and the mother substrate so as to eliminate restrictions on the combination, and to improve the resistance of the LED to static electricity.

[0010]

In order to solve the above-mentioned problems, as a first means, the present invention has a plate-like shape made of a light-transmitting material, and has a first main surface as a light-emitting surface. An edge light system having a light guide member provided with a light diffusing means on a second main surface opposite to the first main surface, and a light source of an LED (light emitting diode) arranged close to a side surface of the light guide member. The planar light source unit, wherein the light guide member is provided with one or more through-holes or blind holes having a function of refracting and reflecting the light emitted from the light source, and the light source and the light source on a side surface of the light guide member. In the case where reflection portions are provided on both sides of the facing portion, the LED is connected to a resistor for voltage adjustment and mounted on an LED substrate, and the LED substrate faces the through hole or the blind hole of the light guide member. It is characterized by being connected to the side surface.

As a second means for solving the above-mentioned problems, the present invention provides a plate-like shape made of a transparent material,
The first main surface is a light emitting surface, and the second main surface facing the first main surface is
An edge light type planar light source unit comprising: a light guide member provided with a light diffusing means on a main surface thereof; and a light source of an LED (light emitting diode) disposed close to a side surface of the light guide member. One or more through holes or blind holes having a function of refracting and reflecting the light emitted from the light source are provided in the light guide member, and reflection portions are provided on both sides of a portion of the light guide member facing the light source on a side surface of the light guide member. In the above, the front LED is connected in parallel with a capacitor for preventing its destruction, mounted on an LED board, and the LED board is coupled to the through hole of the light guide member or a side surface facing a blind hole. It is characterized by the following.

As a third means for solving the above problems, the present invention provides a plate made of a light transmitting material,
The first main surface is a light emitting surface, and the second main surface facing the first main surface is
An edge light type planar light source unit comprising: a light guide member provided with a light diffusing means on a main surface thereof; and a light source of an LED (light emitting diode) disposed close to a side surface of the light guide member. One or more through holes or blind holes having a function of refracting and reflecting the light emitted from the light source are provided in the light guide member, and reflection portions are provided on both sides of a portion of the light guide member facing the light source on a side surface of the light guide member. In this, the front LED is connected to a capacitor for preventing destruction and a resistor for voltage adjustment and mounted on an LED board, and the LED board faces the through hole or the blind hole of the light guide member. It is characterized by being connected to the side surface.

According to a fourth aspect of the present invention, there is provided an external circuit in which the LED substrate is connected to the LED substrate in any one of the first to third means. A contact terminal is provided as connection means to the substrate.

According to a fifth aspect of the present invention, there is provided an external circuit in which the LED board is connected to the LED board in any one of the first to third means. A solder bridge is provided as a means for connecting to the external circuit board as a means for connecting to the board.

As a sixth means for solving the above-mentioned problems, the present invention provides a plate-like shape made of a transparent material,
The first main surface is a light emitting surface, and the second main surface facing the first main surface is
A light guide member provided with light diffusing means on the main surface thereof, and an edge light type planar light source unit having an LED light source disposed in close proximity to the side surface of the light guide member, wherein the light guide member has One or more through-holes or blind holes having the function of refracting and reflecting the light emitted from the light source, and provided with reflecting portions on both sides of a portion facing the light source on the side surface of the light guide member, The LED is connected to a resistor for voltage adjustment or a capacitor for preventing destruction and mounted on an FPC, and a part of the FPC is coupled to a side of the light guide member facing the through hole or a blind hole. It is characterized by having done.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The present embodiment relates to a planar light source unit including a light guide member having a through hole having an action of distributing incident light to the left and right, an LED facing the through hole, and an LED substrate holding the LED and circuit elements. is there. FIG. 1 is a perspective view showing the configuration of the planar light source unit according to the present embodiment. In FIG. 1, reference numeral 10 denotes a planar light source unit, which includes a light guide member 1 and an LED 2 as a light source.
And the like. FIG. 2 shows the LED substrate 13 shown in FIG.
It is the perspective view seen from surface 13a in which D2 was mounted.

The light guide member 1 is made of a light transmitting material such as an optical plastic material, has a plate shape, and has a planar shape of a quadrangle A1A2.
A light emitting portion 11 of A3A4 and an optical path conversion portion 12 having a substantially inverted triangular planar shape are formed. One side (A3-A4) of the quadrilateral of the light emitting portion 11 is simultaneously formed by the substantially inverted triangle of the optical path converting portion 12. The light emitting unit 11 and the optical path changing unit 12 are connected to each other in such a manner as to be the bottom side of. In the embodiment shown in FIG. 1, the light guide member 1 is formed integrally by injection molding or the like. However, after these are separately formed, they are joined together to form the light guide member 1. Is also good.

The upper surface of the light emitting portion 11 has a smooth light emitting surface 11b, and the lower surface 11a of the light emitting portion opposite to the light emitting surface 11b has a plurality of micro-textures or a plurality of hemispherical dot recesses on its surface. And the like. The protruding portion of the optical path conversion unit 12 is chamfered to form a chamfer 12c. Reference numeral 5 denotes an incident portion, which is provided in the chamfered portion 12c and forms a semicircular escape portion. Reference numeral 2 denotes an LED, which is held on the LED substrate 13. As shown in FIG. 2, one main surface 1 of the LED substrate 13
In addition to the LED 2, 3a holds an adjustment resistor 16 and a capacitor 15 for preventing static electricity. And FIG.
As shown in (1), one main surface 13a of the LED substrate 13 is joined to the chamfered portion 12c such that the LED 2 is disposed in the escape portion of the incident portion 5. The main surface 13b opposite to the main surface 13a has two through holes 20a,
0b are provided, each of which is connected to a printed wiring 17 provided on the main surface 13a of the LED substrate 13 as a terminal on a high potential side and a terminal on a low potential side.

Reference numeral 27 denotes a mother board, which is not shown.
D drive circuit is mounted, and printed wirings 27b1 and 2
7b2 is provided. The printed wiring lines 27b1 and 27b2 are connected to the high potential side and low potential side output terminals of the LED drive circuit, respectively. Immediately below the through holes 20a and 20b, the printed wiring 2
In the positional relationship where 7b1 and 27b2 come,
Solder bridges 21a and 21b formed by welding solder are formed between them. As a result, the connection between the through hole 20a and the printed wiring 27b1 and the connection between the through hole 20a and the printed wiring 27b1 are conducted.

The optical path changing portion 12 has a through hole 8 having a substantially inverted triangular planar shape having a function of refracting and reflecting light.
Is provided substantially directly above the LED 2. And through hole 8
Is a portion corresponding to a vertex of a triangle facing the LED 2 (between p1 and p2), a tip curved surface 8b forming a rounded curved surface
And a reflective side surface 8 a is provided on both sides of the curved surface 8. The reflecting side surface 8a can be a paraboloid. In this case, light coming from the focal point of the paraboloid hits the paraboloid, and becomes light parallel to the axis of the paraboloid by total internal reflection. Therefore, by arranging the LED 2 near the common focal point of the reflection side surface 8a, the light reflected on these reflection side surfaces can be distributed to the left and right as almost parallel rays. The through hole 8 is provided with a flat bottom side surface 8c facing the tip curved surface 8b.

The chamfered portion 12c provided with the incident portion 5
On the side surfaces 12d on both sides of the reflector 6, a reflecting portion 6 formed of a plurality of arc grooves parallel to the thickness direction is formed. The grooves of the reflection part 6 are arranged denser as the distance from the LED 2 of the light source increases.
Although the reflecting portion shown in this example is formed of a circular arc groove, a reflecting portion may be formed by forming a rough surface or the like that causes irregular reflection partially or entirely on the side surface instead.

The arrangement of the reflector 3 such as a white sheet close to the lower surface 11a of the light emitting portion 11 is the same as in the prior art. The reflecting plate 3 reflects the light leaked to the outside from the lower surface 11a of the light emitting portion and emitted therefrom.
1 again. A similar effect can be obtained by attaching a silver vapor-deposited film or the like to the lower surface 11a of the emission section instead of the reflection plate 3. Although not shown, if necessary, the side surface 12d on which the reflecting portion 6 formed of the arc groove is formed.
Alternatively, a reflecting member made of a reflecting sheet, silver deposition, or the like may be provided so as to face or contact another side surface. or,
In addition to the above-described inverted triangular through-hole 8, a plurality of through-holes or blind holes (not shown) may be formed at desired positions on the left and right sides thereof to freely adjust the light emission direction. The LED 2 used in the present embodiment is an LE of one of R, G, and B colors.
D, or a white LED.

FIG. 3 is a circuit diagram corresponding to FIG. FIG.
3 and 15, reference numeral 15 denotes a capacitor for preventing static electricity, 16 denotes a resistor for adjusting voltage, and 17 denotes a printed wiring. On one main surface 13a of the LED substrate 13, a capacitor 15 is connected in parallel with the LED 2 and a resistor 16 is connected by a printed wiring 17 so as to conduct in series with the anode A side of the LED 2. Where the LED
The parallel branch portion 18 in which the capacitor 15 is connected in parallel with the capacitor 2 forms an antistatic circuit. LED board 1
3 is provided with a through-hole 20a as a high-potential-side terminal provided on the other main surface 13b.
6 is connected to the opposite side of the LED 2. The through hole 20b as a low potential side terminal is connected to the cathode K of the LED 2 and one electrode of the capacitor 15.

Here, as described above, the through hole 2
Reference numeral 0a denotes an LE (not shown) via the printed wiring 27b1 on the mother board 27 by the solder bridge 21a shown in FIG.
D drive circuit is connected to the high potential terminal
b is connected to the high-potential terminal of the LED drive circuit (not shown) via the printed wiring 27b2 by the solder bridge 21b shown in FIG.

The operation of the planar light source unit according to the present embodiment having the above configuration will be described. A high-potential voltage is applied to the through-hole 20a from the high-potential side of the LED drive circuit (not shown) via the printed wiring 27b1 on the motherboard 27, and from the low-potential side of the LED drive circuit via the printed wiring 27b2. The through hole 2
When a low potential voltage is applied to 0b, the LED shown in FIG.
2, a forward voltage adjusted to a predetermined voltage value by a resistor 16 is applied between an anode A and a cathode K.
2 emits light at a predetermined luminance. Here, as the resistance value of the resistor 16, an appropriate value is selected according to the voltage value of the motherboard and the characteristics of the LED 2.

In this manner, when a voltage is applied to the LED 2 and the LED 2 emits light, as shown in FIG.
The light emitted from 2 enters the optical path changing part 12 of the light guide member 1 from the incident part 5, and the light incident on the tip curved surface 8 b of the through hole 8 passes through the curved surface by refraction and then passes through the inside of the through hole 8. After passing through and passing through the opposite bottom side surface 8c by refraction and entering the light guide member 1 again, the light reaches the light emitting portion 11 and is totally reflected by the light emitting surface 11b, and totally reflected by the light emitting portion lower surface 11a opposed thereto. After being reflected or irregularly reflected, the light finally exits from the light exit surface 11b as illumination light 9 to the outside. Here, the position and the size of the tip curved surface are set so that the incident angle of light to the tip curved surface 8b is smaller than the critical angle θc (with respect to air) of the light guide member 1 even at the maximum.

The light incident on the reflection side surfaces 8a on both sides of the tip curved surface 8b of the through hole 8 is totally reflected on the side surfaces and is divided into right and left, and after being reflected by the reflection portion 6 formed by the arc groove, light is emitted. The light reaches the portion 11 and finally emits to the outside as illumination light 9 from the light emitting surface 11b according to the same principle as described above. . Here, even when the angle of incidence of light on the reflective side surface 8a is the minimum, the light guide member 1 (with respect to air) can be used.
The size and shape of the reflection side surface 8a are set so as to be larger than the critical angle θc. Note that the brightness of the light incident on the reflector 6 tends to decrease as the distance from the LED increases due to the solid angle. However, as described above, the density of the plurality of grooves of the reflecting portion 6 becomes denser as the distance from the LED 2 increases, so that the brightness of the light reflected from the reflecting portion 6 into the light guide member 1 is near the left and right end portions thereof. Is not reduced.

Of the light emitted from the LED 2 and incident from the incident portion 5, the light that escapes from the through hole 8 and enters on both sides thereof reaches the illuminating light emitting portion 11 directly. The light exits from the light exit surface 11b as illumination light 9 to the outside. In this manner, the light that has entered the optical path changing portion 12 of the light guide member 1 from the LED 2 via the incident portion 5 exits the light exit surface 11b via the above three types of routes, and becomes illumination light as a whole. The light emitted by each route has the following characteristics.

That is, the light passing through the curved end surface 8b is the light of the first route, the light reflected by the reflection side surface 8a is the light of the second route, and the light that has deviated from the through hole 8 and is incident on both sides thereof is the light of the first route. If the light of the third route is used, the luminance of the illumination light 9 from the light output surface 11b by the light of the first route is equal to the light output surface 11b.
Large at the center and small at both sides. The luminance of the light 9 emitted from the light exit surface 11b by the light of the second route is equal to the light exit surface 11b.
b is small at the center and large at both sides. The luminance of the light 9 emitted from the light exit surface 11b by the light of the third route is the light exit surface 1
1b is small at the center and large at both sides. Therefore, by appropriately selecting the ratio of the amount of light of the first route to the amount of light of the second and third routes, the characteristics of the luminance are complemented with each other, so that the light emission is achieved. The brightness of the emitted light for illumination over the entire surface 11b can be uniform or substantially uniform.

Such a balance of luminance can be achieved, for example, by appropriately selecting the dimensional ratio between the curved surface 8b of the tip of the through hole 8 and the reflective side surface 8a and the distance between the through hole 8 and the side surface 12d. . Also, at this time, in order to make the luminance of the illumination light uniform, the roughness of the light diffusing surface on the lower surface 11a of the light emitting portion 11 which is the lower surface of the light emitting portion 11 is changed, and the shape and density of the concave portion of the hemispherical dot are changed. Changing according to the place has the same effect as the prior art.

FIG. 4 is a sectional view showing the structure of a main part of a liquid crystal display device using the planar light source unit 10 shown in FIG.
Here, the cut surface is a surface passing through the center of the planar light source unit 10. In the figure, reference numeral 7 denotes a liquid crystal panel, which is arranged above the light exit surface 11b of the light exit portion 11 of the light guide member 1, and is illuminated with uniform brightness by the uniform illumination light 9 from the light exit surface 11b. You.

As described above, the planar light source unit 10 according to the present embodiment makes it possible to illuminate the liquid crystal panel without uneven brightness by using one LED 2, and as described above, the LED 2 Since a voltage adjusted to a predetermined voltage value by the resistor 16 can be applied in accordance with the supply voltage of the substrate 27, restrictions on the combination of the planar light source unit and the mother substrate can be improved. Further, by disposing the capacitor 15 in parallel with the LED 2 on the LED substrate 13 and forming the static electricity prevention circuit 18, it is possible to effectively prevent the LED 2 from being damaged by static electricity. Further, the through holes 2 for the solder bridges 21a and 21b are provided on the LED substrate 13.
0a and 20b, the planar light source unit 1
0 and the mother board 27 can be easily electrically connected.

Next, FIG. 5 is a perspective view showing a configuration near the LED substrate 13 in a modification of the planar light source unit shown in FIG. Other configurations are the same as those of the planar light source unit shown in FIG. In FIG. 4, 23a and 23b
Is a contact terminal, which is made of an L-shaped bent metal rod material, and includes vertical portions 23a1, 23b1 and horizontal portions 23a2, 23b2, respectively. The vertical portion 23a
1 and 23b1 are press-fitted or crimped into through holes 20a and 20b similar to those shown in FIG. 1, and are electrically connected. At this time, a conductive adhesive may be interposed between the through hole and the contact terminal if necessary for conduction. The horizontal portions 23a2, 23b2
Is slightly lower than the lower end surface 13d of the LED substrate 13 and extends in a direction substantially perpendicular to the main surface 13b on the opposite side of the LED 2. The horizontal portions 23a2 and 23b2 are respectively printed wirings 27b1 and 27b on the mother board 27.
2 and joined by a conductive adhesive such as solder.

Thus, similarly to the case of the planar light source unit shown in FIG.
7 electrical connections are made. Here, the circuit components on the main surface 13a of the LED board 13 on which the LEDs 2 are mounted in the present embodiment and the connections thereof are the same as those shown in FIGS. The planar light source unit 10 according to the present embodiment has the same operation and effect according to the same principle as the planar light source unit 10 shown in FIG.

FIG. 6 is a perspective view showing a modification of the planar light source unit shown in FIG. 1, which uses an FPC as a holding member for an LED or the like, but shows a configuration near the FPC.
Other configurations are the same as those of the planar light source unit shown in FIG. In FIG. 6, reference numeral 24 denotes an FPC, on which the LED 2 is mounted relatively near one end 24a.
A capacitor 15 for preventing static electricity and a resistor 16 for adjusting the voltage are mounted in the middle of 4. The other end 4b of the FPC 24 is provided with insertion electrodes 25a and 25b as a high potential side connection terminal and a low potential side terminal. These circuit elements are connected by printed wiring 28 in the same manner as shown in the circuit diagram of FIG. FPC
Reference numeral 24 denotes a portion on both sides of the LED 2, which is joined to the chamfered portion 12 c of the optical path conversion portion 12 of the light guide member 1, and the LED 2 is disposed inside the incident portion 5. The insertion electrode 25a,
25b is inserted into an insertion socket (not shown) provided on a mother board (not shown), and electrical conduction with the mother board is established. The planar light source unit 10 according to the present embodiment has the same operation and effect according to the same principle as the planar light source unit 10 shown in FIG.

In the embodiment of the present invention described above, the LED board 13 or the FP on which the LED 2 is mounted
One capacitor 15 for preventing static electricity and one resistor 16 for voltage adjustment were mounted on C24. However, the present invention is not limited to this.
The effect of applying a predetermined voltage to D can be maintained. Further, even if the resistor 16 is omitted, the effect of preventing static electricity can be maintained.

In the embodiment of the present invention described above, the light guide member (1) of the planar light source unit is provided with the through hole (8) for refracting and reflecting incident light. However, the present invention may alternatively use blind holes that perform a similar function. 7A and 7B are diagrams showing the structure of such a blind hole, wherein FIG. 7A is a top view, and FIG. 7B is a sectional view taken along line AA of FIG. In FIG. 7, reference numeral 14 denotes a blind hole provided in the light guide member 1, the plane shape is an inverted triangle having a pointed tip with respect to the direction of the incident light, and 14a is the blind hole 3 facing the incident light.
And can be a parabolic surface. 1c is a bypass portion below the blind hole 14. When the incident light enters the blind hole 14 and the bypass portion 1c having such a structure, the light incident on the reflective side surface 14a is distributed to the right and left by the total reflection with respect to the blind hole 14, and the blind hole 14 Is incident on the bypass portion 1c thereunder.
It will pass through this portion, either directly or via reflection at the interface, and will enter the portion of the light guide member 1 behind the blind hole 14. In this way, the blind hole 14 has the same effect as the through hole 8 shown in FIG.

[0038]

As described above, according to the present invention, 1
In an edge light type planar light source unit provided with one or a small number of LEDs, a substantially triangular light path conversion part is provided adjacent to a light emission part of a light guide member, and incident light is distributed to the light path conversion part right and left. Along with providing a through hole or a blind hole having an effect of passing a part of the light, by providing the distributed light reflecting portion, the light from the light source is uniformly spread as a whole by efficient optical path conversion, An illumination light having a uniform luminance can be emitted from the light emitting surface of the light emitting portion. Accordingly, it is possible to provide a planar light source unit in which the illumination light is uniform, the cost and power consumption of the light source are reduced, the cost is low, and the planar arrangement efficiency is high. Further, the LED is connected in a predetermined manner together with a capacitor for preventing static electricity and a resistor for voltage adjustment, and is disposed on a holding means such as an LED board independent of the mother board, and is integrated with the light guide member to form a surface. By configuring the shape light source unit, the LE
Always supply the proper voltage to the LED from the D drive circuit, eliminate the restrictions on the combination of the mother board and the LED, and
D can be improved in resistance to static electricity.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a planar light source unit according to an embodiment of the present invention.

FIG. 2 is an LE used in the planar light source unit shown in FIG. 1;
It is a perspective view showing composition of D board.

FIG. 3 is a circuit diagram corresponding to FIG. 2;

FIG. 4 is a cross-sectional view showing a configuration of a main part of a liquid crystal display device using the planar light source unit shown in FIG.

FIG. 5 is a perspective view showing a configuration of an LED substrate and its vicinity in a modified example of the planar light source unit shown in FIG. 1;

FIG. 6 is a perspective view showing a configuration of an FPC on which LEDs are mounted in a modified example of the planar light source unit shown in FIG.

FIG. 7 is a diagram showing a configuration of a blind hole for performing optical path conversion of a planar light source unit according to another embodiment of the present invention.

FIG. 8 is a perspective view showing a configuration of a conventional planar light source unit.

FIG. 9 is a cross-sectional view showing a configuration of the planar light source unit shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light guide member 1 c bypass portion 2 LED 3 reflector 8 a 1, 8 a 2 reflective side surface 5 incident portion 6 reflective portion 7 liquid crystal panel 8 through hole 8 a, 14 a reflective side surface 8 b tip curved surface 9 illumination light 10 planar light source unit 11 light emitting portion 11 a Outgoing part lower surface 11b Outgoing light surface 12d Side surface 12 Optical path changing part 12c Beveled part 1c Bypass part 13 LED board 14 Blind hole 15 Capacitor 16 Resistance 17, 27b1, 27b2, 28 Printed wiring 20a, 20b Through hole 21a, 21b Solder bridge 23a, 23b Contact terminal 24 FPC 27 Mother board

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 33/00 F21Y 103: 02 // F21Y 103: 02 G02F 1/1335 530 F-term (Reference) 2H091 FA23Z FA45Z FB02 LA18 5F041 BB22 BB24 DA20 DA83 EE23 EE25 FF16 5G435 AA00 AA02 AA16 BB12 BB15 EE27 EE34 EE43 EE47 FF03 FF08 GG23 GG26

Claims (6)

[Claims] A first plate formed of a light-transmitting material;
A light guiding member having a light emitting surface as a light emitting surface, and a light diffusing means provided on a second main surface facing the first main surface, and an LED (light emitting diode) disposed close to a side surface of the light guiding member. An edge light type planar light source unit having a light source
One or more through holes or blind holes having a function of refracting and reflecting the light emitted from the light source in the light guide member are provided, and reflection portions are provided on both sides of a portion of the light guide member facing the light source on a side surface. Wherein the LED is connected to a resistor for voltage adjustment and mounted on an LED substrate, and the LED substrate is coupled to a side of the light guide member that faces the through hole or a blind hole. Surface light source unit. 2. A first plate made of a light-transmitting material and having a plate shape.
A light guiding member having a light emitting surface as a light emitting surface, and a light diffusing means provided on a second main surface opposed to the first main surface; and an LED (light emitting diode) disposed close to a side surface of the light guiding member. An edge light type planar light source unit having a light source
One or more through holes or blind holes having a function of refracting and reflecting the light emitted from the light source in the light guide member are provided, and reflection portions are provided on both sides of a portion of the light guide member facing the light source on a side surface. In the provided one, the front LED is connected in parallel with a capacitor for preventing its destruction and mounted on the LED board, and the LED board is coupled to the through hole of the light guide member or to a side surface facing a blind hole. A planar light source unit characterized in that: 3. A first plate made of a light-transmitting material and having a plate shape.
A light guiding member having a light emitting surface as a light emitting surface, and a light diffusing means provided on a second main surface facing the first main surface, and an LED (light emitting diode) disposed close to a side surface of the light guiding member. An edge light type planar light source unit having a light source
One or more through holes or blind holes having a function of refracting and reflecting the light emitted from the light source in the light guide member are provided, and reflection portions are provided on both sides of a portion of the light guide member facing the light source on a side surface. In the provided one, the front LED is connected to a capacitor for preventing destruction thereof and a resistor for voltage adjustment and mounted on the LED board, and the LED board is opposed to the through hole or the blind hole of the light guide member. A planar light source unit, wherein the planar light source unit is coupled to a side surface. 4. The planar surface according to claim 1, wherein a contact terminal is provided on the LED board as connection means for connecting to an external circuit board to which the LED board is connected. Light source unit. 5. A method according to claim 1, wherein said LED board is provided with a solder bridge as connecting means to an external circuit board as connecting means to an external circuit board to which said LED board is connected. The planar light source unit according to any one of the above. 6. A first plate made of a light-transmitting material and having a plate shape.
A light guide member provided with a light diffusing means on a second main surface opposite to the first main surface, and a light source of an LED disposed close to a side surface of the light guide member. An edge light type planar light source unit having a light guide member, wherein the light guide member has at least one through hole or a blind hole having a function of refracting and reflecting light emitted from the light source, In those provided with reflection portions on both sides of a portion facing the light source on the side surface, the LED is connected to a resistor for voltage adjustment or a capacitor for preventing destruction and mounted on an FPC,
A planar light source unit, wherein a part of the FPC is coupled to a side surface of the light guide member that faces the through hole or the blind hole.