KR20020032384A - Surface light source device and image display device - Google Patents

Abstract

PURPOSE: To prevent uneveness in brightness of the exit light caused by deformation of a light control sheet. CONSTITUTION: A reflector 13 of a light source unit 11 comprises a first plate- like part 37 tightly contacting an exit surface 36 end part on an incident surface 10 side of a light guide plate 4, and a second plate-like part 38 supported by a reflector support 14. A projection 41 formed at the second plate-like part 38 of the reflector 13 hooks with a hole formed at a plate-like base part 43 of the reflector support 14 so that the reflector 13 is aligned with the reflector support 14. Thus the deflection of the reflector 13 is corrected, keeping an appropriate interval between a fluorescent lamp 12 and the incident surface 10 of the light guide plate 4.

Description

Surface light source device and image display device {SURFACE LIGHT SOURCE DEVICE AND IMAGE DISPLAY DEVICE}

The present invention provides a surface light source device for illuminating an image display unit such as a liquid crystal display panel used in a portable personal computer, a navigation device, a portable information communication terminal, an electronic dictionary, various monitors, etc. in a planar shape, and an image display device having the same surface light source device. It is about.

For example, a liquid crystal display device as an image display device is used for a portable personal computer or the like. In most cases, the liquid crystal display device is equipped with a surface light source device. The planar illumination light emitted from the surface light source device irradiates a liquid crystal display panel (image display unit) to display an image on the display screen of the liquid crystal display panel.

16 and 18 show the surface light source device 101 used in this type of liquid crystal display device 100. As shown in both figures, the surface light source device 101 is provided with the resin frame 2 which accommodates all the members. In the frame 2, the reflective sheet 3, the light guide plate 4, and the plurality of light control sheets 5 to 8 are sequentially accommodated, and the light guide plate 4 is disposed on the incident end surface 10 (side cross section) side. The light source unit 11 is arranged.

The light source unit 11 reflects the fluorescent lamp 12 as a rod-shaped light source disposed to face the incident end face 10, and the light from the fluorescent lamp 12 to guide the incident end face 10 of the light guide plate 4. The reflector 13 and the reflector support 14 are made of metal. The reflector support 14 is made of metal and is fixed to the frame 2 in a state in which the fluorescent lamp 12 is accommodated in the reflector 13. .

The surface light source device 101 emits light from the fluorescent lamp 12 in a plane shape from the exit surface 36 of the light guide plate 4, and emits light from the light guide plate 4 into a plurality of light control sheets ( By passing through 5 to 8), the light emitted from the light guide plate 4 is directed to the liquid crystal display panel 16. As a result, uniform and bright planar illumination light is formed. The liquid crystal display panel 16 is illuminated by this planar illumination light.

In recent years, especially in the liquid crystal display device 100 used for a portable personal computer, higher performance is calculated | required about carrying of a portable personal computer, making screen viewing easy, etc. Therefore, while aiming at thinning and weight reduction, the enlargement of the effective display area (the area which can actually display a screen) is planned. As a result, the ineffective part (circumference part) of the liquid crystal display panel 16 in the liquid crystal display device 100 is becoming small. The circumferential portion not used for such an image display is also referred to as a "frame portion" in comparison with a picture fitted to a picture frame. According to this expression, "narrow-frameization (narrowing the frame part)" has been advanced recently.

In order to cope with such narrow frame formation, the design which makes thickness of the resin frame 2 thin is employ | adopted. As a result, the rigidity of the frame 2 is lowered, and in particular, the rigidity of the portion (first side 21) in which the fluorescent lamp 12 is accommodated becomes small.

Therefore, in order not to destabilize support of all the members of the frame 2, the following measures are taken. In other words, a pair of sides [second side 30 and third side 31] in which the plate-shaped base 43 of the reflector support 14 is substantially orthogonal to the first side 21 of the frame 2. )] Is fixed to the lower surface of the lower surface, and the side wall portions 44 to 46 standing up from the plate-shaped base 43 of the reflector support 14 are outside the first to third sides 21, 30, and 31. To fit in. Thereby, the frame 2 can be reinforced with the reflector support body 14.

However, if such a technique is adopted, the thickness of the first side 21 of the frame 2 becomes very thin compared with the thickness of the other side. For this reason, the shrinkage amount after injection molding becomes small on the first side 21 and on the other side. If the difference becomes remarkable, the first edge 21 will be slightly curved inward as shown in the dashed line in Fig. 16 or in Fig. 19.

In addition, in FIG. 16, in order to emphasize the deformation | transformation of the frame 2, the deformation amount is exaggerated and shown. In this case, if the amount of curvature deformation of the first side 21 of the frame 2 is greater than the size of the gap between the frame 2 and the light control sheets 5 to 8, the light is controlled by the frame 2. Units 5 to 8 are compressed. Thereby, the case where wrinkles generate | occur | produce in the light control sheets 5-8, and the luminance nonuniformity of the emitted light resulting from this may also arise.

The reflector 13 is usually manufactured by molding a metal sheet by sheet metal processing, and constitutes a long plate member having an almost U-shaped cross section as shown in FIGS. 17 and 18. Doing. Therefore, compared with the reflector support body 14 which also functions as a reinforcement member of the frame 2, rigidity is small. Moreover, the rubber lamp support bodies 22 and 23 which are normally fitted to the fluorescent lamp 12 are engaged with each of the both ends of this reflector 13. Both ends thereof are supported by the frame 2 together with the lamp supports 22 and 23. This means that the intermediate part between the both ends is not caught by the frame 2 or the reflector support 14.

Therefore, as shown by the dashed-dotted line in FIG. 17, when the reflector 13 is warped at the time of sheet metal processing, as shown in FIGS. 20 to 21, an intermediate portion of the reflector 13 is required on the light guide plate 4 side. It goes over. For this reason, the space | interval of the fluorescent lamp 12 and the incidence end surface 10 of the light guide plate 4 becomes narrow, and the fluorescent lamp 12 inside the light guide plate 4 also from the exit surface 36 side of the light guide plate 4. ) Light L is incident.

By this phenomenon, the area | region of the part whose brightness is high by the quantity of incident light from this emission surface 36 side will generate | occur | produce. Moreover, the wrinkles which light control sheets 5-8 are compressed by the reflector 13, and the wrinkles which generate | occur | produce in the light control sheets 5-8 are scattered, and it becomes easy to become a cause which produces a luminance nonuniformity.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above. An object of the present invention is to improve the surface light source device to effectively prevent the luminance non-uniformity of the emitted light caused by the deformation of the frame or the reflector, so that a uniform and bright light output can be obtained. Moreover, an object of this invention is to provide the display apparatus which can display high quality using such an improved surface light source device.

1 is a plan view showing a surface light source device according to a first embodiment of the present invention.

2 is an exploded plan view showing a surface light source device according to the first embodiment.

3 is an enlarged cross-sectional view of the surface light source device taken along the line A-A in FIG.

4 is a plan view of the frame;

FIG. 5 is a view from the direction B in FIG. 4 (incident cross-sectional view). FIG.

FIG. 6 is a view seen from the direction C in FIG. 5 (shown on the lower surface of the first side of the frame);

FIG. 7 is an enlarged cross-sectional view taken along the line D-D in FIG. 5.

FIG. 8 is a view showing a state of engagement between a hook of a reflector support and a protrusion of a frame; FIG.

9 is a plan view of a reflector containing a fluorescent lamp;

10 is a plan view of the light source unit;

11 is a plan view of a frame on which a light source unit is mounted.

12 is a perspective view partially showing the reflector and the reflector support;

Fig. 13 shows a fluorescent lamp according to a second embodiment of the present invention.

14 is a diagram showing a fluorescent lamp according to a modification of the second embodiment.

FIG. 15 is a perspective view showing two examples of a ring, FIG. 15A shows a first example of a ring, and FIG. 15B shows a second example of a ring.

16 is a plan view of a conventional surface light source device.

17 is a plan view showing a conventional fluorescent lamp and a reflector.

18 is an enlarged cross-sectional view taken along the line E-E in FIG. 16.

Fig. 19 is a sectional view of a surface light source device showing a curved deformation state of the frame.

20 is a cross-sectional view showing a problem occurrence state of a conventional surface light source device due to the deflection of the reflector.

FIG. 21 is an enlarged cross-sectional view of a portion of FIG. 20; FIG.

※ Explanation of codes for main parts of drawing

1: surface light source device 2: frame

4: Light guide plate 5-8: Light control sheet

10: incident cross section (side cross section) 11: light source unit

12 fluorescent lamp (bar-shaped light source) 13 reflector

14 reflector support 16 liquid crystal display panel (image display panel)

26: hook 35: O ring

36: exit surface 37: the first plate shape

38: 2nd plate-shaped part 50: liquid crystal display device (image display apparatus)

54: O ring 55: ring

The present invention is applied to a surface light source device in which light from a light source unit attached to a frame is emitted in a plane shape through a light guide plate and a light control sheet accommodated in the frame. According to the present invention, the light source unit of the surface light source device includes a rod-shaped light source disposed so as to face an incident end surface of the light guide plate, the rod-shaped light source, and the light of the rod-shaped light source is incident on the light guide plate. The sheet metal processing reflector which guides to a cross section, and the reflector support body mounted to the said frame in the state which supported this reflector are provided.

In addition, according to one improved aspect of the present invention, the reflector has a first plate-shaped portion which is in close contact with an end portion of an exit surface on the incident end surface side of the light guide plate, and a second plate-shaped portion supported by the reflector support. . Here, the second plate-like portion and the reflector support are engaged with the concave-convex and positioned so as to be positioned.

By such an improvement, even if the reflector is bent and deformed, since the reflector and the reflector support are engaged with irregularities, the reflector is positioned with respect to the reflector support, thereby suppressing or correcting the deflection or deformation of the reflector. As a result, the distance between the rod-shaped light source and the incident end surface of the light guide plate is maintained at an appropriate dimension. In addition, it is avoided that the light control unit is compressed by the reflector to cause deformation (wrinkling).

In another improvement of the present invention, at least one pair of annular members are fitted to the rod-shaped light source, and a plurality of annular members are adjacent to each other between the pair of annular members. It is fitted to adjoin. The rod-shaped light source is supported in the reflector through these annular members. Here, for example, an O ring or a substantially C-shaped ring can be used for the annular member.

In addition, the annular member may be formed in a shape where the outer shape is almost in close contact with the inner surface of the reflector and the incident end surface of the light guide plate, and the inner surface may be formed in a shape that faces the annular light source. In other words, the annular member may be disposed so as to surround the outer circumference of the bar-shaped light source, so that the bar-shaped light source can be supported in the reflector.

By such an improvement, even if the reflector causes deformation due to warpage, and thus a force is generated to cause a curvature deformation in which the rod-shaped light source approaches the incident surface of the light guide plate, it is arranged between the pair of annular members. This can be pushed back by the elastic force of the plurality of annular members. Therefore, curvature deformation of the rod-shaped light source is suppressed to some extent, so that the space between the rod-shaped light source and the light guide plate is maintained. At the same time, the light control sheet is also compressed with the reflector to prevent wrinkles.

In still another improved aspect of the present invention, at least one pair of annular members are fitted to the rod-shaped light source, and a substantially cylindrical elastic member is fitted between the annular members. The rod-shaped light source is supported in the reflector through the annular member and the substantially cylindrical elastic member.

By such an improvement, the substantially cylindrical elastic member exhibits the same function as the plurality of adjacent annular members described above to suppress the deflection of the reflector. As a result, the light control sheet is prevented from being compressed by the reflector to generate wrinkles.

Next, according to still another improved form, the hook formed on the reflector support is engaged with the concave-convex surface of the frame with respect to one side positioned on the side where the light source unit is mounted. According to such an improvement, even if an action that causes deformation such as expansion of one side of the frame by heat of a rod-shaped light source occurs, no problem occurs.

That is, since the hook of the reflector support body is engaged with one side of the frame, deformation of the frame is prevented by the hook of the reflector support body. As a result, the distance between the rod-shaped light source and the incident end surface of the light guide plate is properly maintained, and generation of wrinkles in the light control sheet is prevented by deformation of the frame. As a result, bright surface illumination without luminance unevenness is possible.

The image display device according to the present invention is configured by illuminating the image display panel with the planar light emitted from the surface light source device by combining the surface light source device improved in all the above forms with the image display panel. Needless to say, all the advantages of the above-described improvement are reflected in such an image display device. In other words, by illuminating the image display panel with bright surface light without any unevenness, the quality of the display image can be improved.

Embodiment

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail, referring drawings. In addition, the drawings have exaggerated partly as necessary for easy understanding.

(1) First embodiment

First, referring to FIGS. 1-3, the surface light source device 1 which concerns on 1st Embodiment of this invention is shown. FIG. 1 shows the planar light source device 1 in a plan view, and FIG. 2 shows the planar light source device 1 in an exploded view. 3 has shown the expanded cross section along the line A-A in FIG.

(Schematic Configuration of Surface Light Source Device)

As shown in these drawings, the surface light source device 1 includes a frame 2 accommodating all members, a reflective sheet 3, a light guide plate 4, and a plurality of elements sequentially superposed in the frame 2. The long light control sheets 5 to 8 and the light source unit 11 are provided. The light source unit 11 is mounted to the frame 2 so as to face the incident end surface (one side cross section 10) of the light guide plate 4.

The light source unit 11 includes a reflector support 14 supporting a rod-shaped light source 12, a reflector 13 containing a rod-shaped light source 12, and a reflector 13 containing a rod-shaped light source 12. ). In this embodiment, a fluorescent lamp is employed as the rod-shaped light source 12. Rod-shaped light sources other than fluorescent lamps may be employed. As is well known, the reflector 13 has a function of reflecting the light of the fluorescent lamp 12 and guiding it to the incident end face 10 of the light guide plate 4.

(frame)

As shown in Figs. 1 to 8, the frame 2 is a substantially rectangular member made of white synthetic resin such as PC (polycarbonate) or PMMA (polymethyl methacrylate), which is produced by injection molding. will be. In the frame 2, the light guide plate accommodating part 15 which accommodates the reflection sheet 3, the light guide plate 4, and the light control sheets 5 to 8, and an image display panel 16 such as a liquid crystal display panel are placed on top. An image display panel accommodating portion 17 to be accommodated with a slight gap to the surface of the light control sheet 8 of the light control sheet 8 and a light source accommodating portion for accommodating the fluorescent lamp 12 and the reflector 13 of the light source unit 11. 18 is formed.

And the thickness of each part of the frame 2 is formed as thin as possible in order to reduce the size and weight of the surface light source device 1, and the bottom face 20 of the light guide plate accommodating part 15 "perforated shape". It is. "Perforated shape" means removing a part of the constituent material to form a shape such as an opening, and is one of the weight reduction means.

The bottom face 20 of the light guide plate accommodating portion 15 can support the reflective sheet 3, the light guide plate 4, and the like, and further control components (electric circuits, wiring, etc.) of the image display panel 16; ) Can be mounted.

In addition, as shown in detail in FIGS. 4 to 7, the frame 2 is provided with a fluorescent lamp (to be described later) at both ends of the lower surface side of one side (first side; 21) on the incident end surface 10 side of the light guide plate 4. The lamp support accommodating recesses 24 and 25 to which the lamp supports 22 and 23 at both ends of 12 are engaged are formed, respectively.

And the reflector 13 is accommodated in the lower surface side of the 1st side 21 of the frame 2. As shown in FIG. Therefore, the 1st side 21 of the frame 2 is formed in thickness thinner than the other side, and its rigidity is smaller than the other side. Thus, the first side 21 is reinforced with the reflector support 14. That is, as shown in detail in FIG. 3 and FIG. 8, a substantially rectangular hook accommodating recess 27 in which a plurality of hooks 26 of the reflector supporter 14 are engaged with the upper surface of the first side 21. And the projections 28 engaged with the plurality of hooks 26 of the reflector support 14 are formed.

The hook support recess 14 of the first side 21 is accommodated in the hook receiving recess 27 of the first side 21, and the reflector support 14 is provided on the projection 28 of the first side 21. Hook 26 on the hook. In this way, the first side 21 of the frame 2 and the reflector support 14 can be detachably integrated. Moreover, curvature deformation (refer to the dashed-dotted line of FIG. 16) inside the 1st side 21 of the frame 2 can be prevented.

Here, it is preferable to determine the shape of the hook 26, the amount of gripping the hook accommodating portion 27, and the like so that the upper surface of the hook 26 does not protrude upward from the upper surface of the first side 21. By doing in this way, another part etc. are hardly caught by the hook 26, and the hook 26 becomes difficult to peel off from the projection 28. As shown in FIG.

In addition, the frame 2 is formed on both ends of the light guide plate 4 and the reflective sheet 3 inside the second side 30 and the third side 31 which are substantially orthogonal to the first side 21. Positioning projections 34 that engage with the rectangular cutouts 32 and 33 are formed, respectively. As a result, even if vibration or impact is applied to the surface light source device 1, the movement of the light guide plate 4 in the frame 2 to be displaced at a fixed position is restricted, and the light guide plate 4 collides with the fluorescent lamp 12. Avoided. As a result, breakage of the fluorescent lamp 12 is prevented.

(Light source unit)

As shown in FIGS. 1-3 and 9-12, the light source unit 11, the fluorescent lamp 12, the reflector 13 which accommodates this fluorescent lamp 12, (refer FIG. 9), The reflector support body 14 which supports the reflector 13 is provided (refer FIG. 10).

Rubber lamp supports 22 and 23 are engaged with both ends of the fluorescent lamp 12. Moreover, a pair of rubber O-rings (round ring; an example of an annular member; 35) is fitted in space at mutually symmetrical position with respect to a center part (refer FIG. 2). The reflector support 14 is engaged with the end of the reflector 13 and simultaneously with the lamp support accommodating recesses 24 and 25 formed in the first side 21 of the frame 2 (FIG. 5, see FIG. 6).

In addition, the O-rings 35, 35 prevent the fluorescent lamp 12 from directly contacting the inner surface of the reflector 13, and protect the fluorescent lamp 12 from impact so as to protect the fluorescent lamp 12 from impact. It has an action of supporting elastically in the reflector 13. In addition, the cable 39 on the ground side is accommodated in the space between the first side 21 and the reflector 13 (see FIG. 3).

The reflector 13 is manufactured by sheet metal processing such as a stainless steel sheet. The reflector 13 is connected to the first plate-shaped portion 37 which is in close contact with the end of the exit surface 36 of the light guide plate 4 and the reflector support 14 which is in close contact with the lower surface side of the reflective sheet 3. It is provided with the 2nd plate-shaped part 38 supported, and the standing wall part 40 which connects these 1st plate-shaped part 37 and the 2nd plate-shaped part 38. As shown in FIG. As a whole, the reflector 13 may be a long body (belt-shaped member) having a length approximately the same as that of the first side 21 of the frame 2.

The first plate-shaped portion 37 is configured to prevent the intrusion of light into the light guide plate 4 from the end of the light emitting plate 4 at the incident end surface 10 side of the emission surface 36. Moreover, the projection 41 which protrudes to the lower surface side is formed in the substantially center part of the longitudinal direction (direction along the axis line of the fluorescent lamp 12) of the front-end | tip of the 2nd plate-shaped part 38. As shown in FIG. And the hole 42 which engages with the projection 41 of this reflector 13 is formed in the plate-shaped base 43 of the reflector support body 14.

Thus, by engaging the projection 41 of the reflector 13 to the hole 42 of the reflector support 14, even if the reflector 13 is bent by sheet metal processing (see the dashed line in Fig. 17), The warpage can be corrected. Moreover, even if the action which causes the deformation of the reflector 13 arises, the reflector 13 is not deformed and the reflector 13 can be positioned with respect to the reflector support body 14.

The reflector support 14 includes a plate-shaped base 43 which is fixed to the second side 30 and the third side 31 of the frame 2 by screws (not shown), and the first of the frame 2. Side wall portions 44 to 46 which stand up from the plate-shaped base 43 are provided to support the outer surface of the side 21, the outer surface of the second side 30, and the outer surface of the third side 31, respectively. The reflector support 14 is formed by performing sheet metal processing on a metal plate such as a stainless steel sheet as in the reflector 13 described above, but is thicker and larger in rigidity than the reflector 13 described above. Thus, the frame 2 is reinforced.

Moreover, the reflector support body 14 engages with the projection 28 formed in the 1st side 21 at the upper end of the side wall part 44 located in the outer surface side of the 1st side 21 of the frame 2. A pair of hooks 26 are bent.

And the hook 26 is engaged with the projection 28 of the frame 2, and the curvature deformation to the inner side of the 1st side 21 of the frame 2 is prevented. In addition, the hook 26 is provided with the hole 26b which engages with the projection 28 of the 1st side 21 inward of the substantially rectangular frame part 26a. In addition, the rib 52 which extends so as to substantially follow the axial direction of the fluorescent lamp 12 is located at the tip side of the plate-shaped base 43 of the reflector support 14 and on the lower surface side of the reflective sheet 3. 53) is formed, thereby increasing the rigidity of the reflector support 14.

Assembling of the light source unit 11 is performed as follows, for example. First, as shown in FIGS. 3 and 9, the fluorescent lamp 12 is accommodated in the reflector 13. Subsequently, as shown in FIG. 10, the reflector 13 is assembled to the reflector support 14. At this time, as mentioned above, the projection 41 of the reflector 13 is engaged with the hole 42 of the reflector support 14. That is, the 2nd plate-shaped part 38 of the reflector 13 and the plate-shaped base 43 of the reflector support body 14 are engaged with unevenness.

Thereby, while reflecting the reflector 13 and the reflector support body 14, the curvature distortion of the reflector 13 can be corrected.

11, the hook 26 of the reflector support body 14 is engaged with the projection 28 of the 1st side 21 of the frame 2, and the 2nd plate-shaped part of the reflector 13 ( 38 and screws (not shown) are inserted into the screw holes 47 and 48 of the plate-shaped base 43 of the reflector support 14, and the reflector 13 and the reflector support 14 are connected to the frame 2 by the screws. ) Is fixed to the lower surface side of the second side 30 and the third side 31.

Thereby, the frame 2 and the light source unit 11 are integrated. Thereafter, the reflection sheet 3, the light guide plate 4, and the light control sheets 5 to 8 are accommodated in the light guide plate accommodating portion 15 of the frame 2 to assemble the surface light source device 1 (FIGS. 1 to 1). See FIG. 3).

Next, the liquid crystal display panel 16 is accommodated in the image display panel accommodating part 17 of the frame 2, and the image display apparatus (here, liquid crystal display device) 50 is assembled (refer FIG. 3).

(Light guide plate)

The light guide plate 4 is formed of PC, PMMA, a cycloolefin-based resin material and the like excellent in light transmittance. The longitudinal cross-sectional shape along the direction orthogonal to the fluorescent lamp 12 has a wedge shape that becomes thinner as it moves away from the fluorescent lamp 12. The shape of the exit surface (upper surface) 36 is substantially rectangular. At both ends of the light guide plate 4 on the incident end face 10 side, a substantially rectangular cutout 32 is formed. This cutout 32 is engaged with the positioning projection 34 formed inside the second side 30 and the third side 31 of the frame 2.

In addition, the external dimension of this light guide plate 4 is determined in consideration of the manufacturing error etc. in addition to the difference of the temperature expansion characteristic of the light guide plate 4 and the frame 2, or the difference of a moisture absorption expansion characteristic. Therefore, under the condition that the surface light source device 1 or the image display device (liquid crystal display device) 50 is used, between the side surface of the light guide plate accommodating part 15 and the other side cross-section except for the incident end surface 10, Each gap is supposed to occur.

In addition, unlike the flexible sheet-like member like the reflective sheet 3 and the light control sheets 5 to 8 described later, the light guide plate 4 has sufficient rigidity that is not easily deformed. As is known, when the fluorescent lamp 12 is turned on, light is introduced into the light guide plate 4 from the incident end face 10. Light propagates inside the light guide plate 4 and is gradually emitted from the exit surface 36 in the propagation process. In addition, various means are known conventionally about the means for emitting light from the emission surface 36, and these means may be suitably applied.

(Reflective sheet)

The reflective sheet 3 is a sheet member made of a resin material excellent in light reflectivity, for example, white PET (polyethylene terephthalate). The size and the shape correspond to the rectangular surface (rear surface) 51 opposite to the exit surface 36 of the light guide plate 4. As is known, the reflective sheet 3 reflects the light leaked from the back surface 51 and returns to the inside of the light guide plate 4 to prevent the loss of light. The reflective sheet 3 is provided with the notch part 33 corresponding to the notch part 32 of the light guide plate 4 at the both ends of the front end part of the fluorescent lamp 12 side. This cutout 33 is engaged with the positioning projection 34 formed inside the second side 30 and the third side 31 of the frame 2.

(Light control sheet)

The light control sheet disposed in the present embodiment includes a diffusion sheet (first light control sheet; 5) disposed so as to face the exit surface 36 of the light guide plate 4, and a pair of prism sheets disposed outside thereof. 2nd and 3rd light control sheets: 6,7) and the protective sheet (4th light control sheet; 8) arrange | positioned at the outer side.

The function of each light control sheet is already known. In other words, the diffusion sheet 5 has a function of diffusing light emitted from the emission surface 36 to achieve uniform luminance distribution. Subsequently, the prism sheets 6 and 7 modify the propagation direction of light in the front direction, and increase the ratio of the light which can be effectively used for illumination. The protective sheet (fourth light control sheet) 8 has a function of preventing damage to the prism sheet 7 disposed inside thereof, and is provided with weak light diffusivity.

These light control sheets 5-8 are formed of the resin material excellent in light transmittance, for example, PET (polyethylene terephthalate), and have a substantially rectangular shape corresponding to the exit surface 36. FIG. And these light control sheets 5-8 are sequentially accommodated in the light guide plate accommodating part 15 of the upper side of the light guide plate 4, and are caught by the frame 2 by fixing means, such as a tape or a clip which is not shown in figure. have. Thereby, the movement which the light control sheets 5-8 displace in the frame 2 is prevented.

(Effects of the First Embodiment)

The surface light source device 1 according to the present embodiment configured as described above has the following effects.

(a) The projections 28 formed on the first side 21 of the frame 2 are engaged with the hooks 26 of the reflector support 14, so that the deformation of the first side 21 curved inward is corrected. . Therefore, the light control sheets 5-8 are suppressed by the 1st side 21, and it does not generate | occur | produce wrinkles. In addition, unevenness in luminance of the emitted light resulting from wrinkles of the light control sheets 5 to 8 is prevented.

(b) The protrusion 41 formed in the second plate-shaped portion 38 of the reflector 13 is engaged with the hole 42 formed in the plate-shaped base 43 of the reflector support 14, so that the reflector support 14 is provided. The reflector 13 can be positioned with respect to. Therefore, even if the reflector 13 is curvedly deformed inwardly as shown in Fig. 17 (even if bending occurs due to sheet metal processing), the deformation is corrected. As a result, the interval between the incident end surface 10 of the fluorescent lamp 12 and the light guide plate 4 can be maintained in an appropriate state.

Moreover, the edge part by the side of the incident end surface 10 of the exit surface 36 of the light guide plate 4 can be reliably shielded by the 1st plate-shaped part 37 of the reflector 13. Therefore, the phenomenon that the light of the fluorescent lamp 12 enters into the light guide plate 4 from the emission surface 36 can be prevented. In addition, as described above, since the deformation of the reflector 13 can be corrected and the distance between the fluorescent lamp 12 and the incident end surface 10 of the light guide plate 4 can be maintained in an appropriate state, the light control sheet 5 8) is suppressed by the reflector 13, and wrinkles are not generated. Therefore, occurrence of uneven brightness of the emitted light due to light incidence from the emitting surface 36 into the light guide plate 4 is prevented.

(c) The projection 41 of the reflector 13 and the hole 42 of the reflector support body 14 engaged with the projection 41 are covered with the reflective sheet 3. Therefore, the projection 41 of the reflector 13 and the hole 42 of the reflector support body 14 are not seen from the exit surface 36 upper side. In addition, problems such as light leakage do not occur.

(d) Since the liquid crystal display panel 16 is illuminated with the planar uniform illumination light by the surface light source device 1 as described above, an image display that is brighter and easier to see becomes possible.

(e) A rib extending to substantially follow the axial direction of the fluorescent lamp 12 in a portion located at the distal end side of the plate-shaped base 43 of the reflector support 14 and on the lower surface side of the reflective sheet 3 ( 52, 53) are formed. This increases the rigidity of the reflector support 14.

In this embodiment, various modifications are allowed as follows. That is, in this embodiment, the aspect which forms the protrusion 41 of the reflector 13 and the hole 42 of the reflector support body 14 in one point was illustrated. However, this does not limit the present invention. For example, a plurality of projections 41 of the reflector 13 and a plurality of holes 42 of the reflector support 14 may be formed.

Moreover, in this embodiment, the projection 41 is formed in the front-end | tip of the 2nd plate-shaped part 38 of the reflector 13. As shown in FIG. However, this does not limit the present invention. For example, you may form in the part (part of the 2nd plate-shaped part 38) located in the lower surface side of the reflecting sheet 3. As shown in FIG.

In addition, in this embodiment, the projection 41 is formed so that the front-end | tip of the 2nd plate-shaped part 38 of the reflector 13 may be bent to the lower surface side (the plate-shaped base 43 side of the reflector support 14). It is. However, this also does not limit the present invention. For example, the second plate-shaped portion 38 may be partially expanded (inflated) toward the lower surface side. In this case, the plate-shaped base 43 of the reflector support 14 is formed with a recess or a hole that engages with irregularities in the expanded projection.

In addition, the protrusion may be formed in the plate-shaped base 43 of the reflector support 14, and the hole or the recess engaged with the protrusion may be formed in the second plate-shaped portion 38 of the reflector 13. . In this case, it is preferable that the projection does not protrude to the upper surface side of the second plate-shaped portion 38.

Moreover, a projection is formed in the lower surface side of the hook 26 of the reflector support body 14, and the recessed part which engages with this projection is formed in the 1st side 21 of the frame 2, and the projection of the hook 26 The curved shape of the first side 21 of the frame 2 may be corrected by engaging the recessed portion of the first side 21 with the unevenness.

In addition, in this embodiment, although the aspect which forms the hook 26 in two places on the reflector support body 14 was illustrated, this does not limit this invention. For example, the 1st side 21 of the frame 2 is shown. The hook 26 and the protrusion 28 engaged therein may be one, and the hook 26 and the protrusion 28 engaged thereon may be three or more, as long as the curvature of the blade can be corrected. It may be formed.

(2nd embodiment)

In this embodiment, it is different from the means employ | adopted in 1st Embodiment mentioned above as a means for correcting the curvature of the reflector 13. As shown in FIG. That is, in the fluorescent lamp 12 in the surface light source device 1 which concerns on this embodiment, as shown in FIG. 13, in addition to a pair of O ring (ring-shaped member; 35, 35), these pairs A plurality of O-rings (ring-shaped members) 54 are fitted to each other in a state in which a plurality of O-rings (ring-shaped members) 54 are close to each other or close to each other.

With such a configuration, even if the reflector 13 generates warping inwardly curved (see Fig. 17), an unsuitable situation is avoided.

That is, in general, warping inward of the reflector 13 causes curvature deformation of the fluorescent lamp 12. Here, the amount of deformation of the fluorescent lamp 12 is, of course, maximized at approximately the center. If this is left to stand, the maximum deformation part is assumed to be in contact with the incident end surface 10 of the light guide plate 4 in some cases.

Therefore, in this embodiment, in order to avoid such a situation, the some O-ring 54 is arrange | positioned closely in the substantially center part (namely, the largest deformation part) of the lamp 12. As shown in FIG. In addition, it is thought that such a plurality of O-rings 54 may be suppressed by a considerable force on the incident end face 10. However, in the present embodiment, since the suppression pressure received from the incident end face 10 can be dispersed by the plurality of O rings 54, such a concern can be solved.

That is, compared with the case where only one O ring 35 identical to the pair of 0 rings 35 and 35 is disposed at the center of the fluorescent lamp 12, the amount of elastic deformation of the individual O rings 54 is reduced. A sufficient space can be secured between the light guide plate 4 and the fluorescent lamp 12.

In other words, the deflection of the reflector 13 is corrected by the plurality of O-rings 54 arranged in the substantially center portion of the fluorescent lamp 12, so that sufficient space is provided between the fluorescent lamp 12 and the light guide plate 4. It can be secured.

Here, the width dimension W of the some O-ring 54 arrange | positioned at the substantially center part of the fluorescent lamp 12, when making the wire diameter of a pair of O-rings 35 and 35 into d, W: It is preferable to set it as 2d-4d. At W <2d, there is a fear that the effect of correcting the reflector 13 cannot be sufficiently obtained. Moreover, in W> 4d, the part which blocks light becomes too large, and there exists a possibility that this light shielding part may be seen as the nonuniformity of the brightness of emitted light.

Thus, also in this embodiment, since the deformation | transformation of the reflector 13 can be correct | amended, the space between the fluorescent lamp 12 and the incident cross section 10 can fully be ensured. Moreover, the edge part by the side of the incident end surface 10 of the exit surface 36 can be reliably shielded by the 1st plate-shaped part 37 of the reflector 13, and the light of the fluorescent lamp 12 is carried out of the light-guide plate 4 The phenomenon which injects into the light guide plate 4 from the exit surface 36 can be prevented.

In addition, as described above, since the deformation of the reflector 13 can be corrected and the space between the fluorescent lamp 12 and the incident end face 10 can be sufficiently secured, the light control sheets 5 to 8 have the reflector ( 13) it is suppressed and does not produce wrinkles. Therefore, according to the present embodiment, similarly to the first embodiment described above, occurrence of luminance non-uniformity of the emitted light due to incident light from the exit surface 36 of the light guide plate 4 can be prevented.

In addition, 2nd Embodiment mentioned above illustrated the aspect arrange | positioned at the substantially center part of the fluorescent lamp 12 in the state which the several O-ring 54 was in close contact. However, this does not limit the present invention.

For example, as shown in FIG. 14 and FIG. 15A, a substantially cylindrical rubber ring (elastic member) 55 may be fitted to a substantially central portion of the pair of O rings 35 and 35. Here, as shown in FIG. 15B, the ring 55 may facilitate the operation of forming the slit 56 over the entire length in the width direction and fitting the fluorescent lamp 12.

Also with such a configuration, the same effects as in the above-described second embodiment can be obtained. In the case of adopting this modification, the width dimension W of the ring 55 is set to W: 2d to 4d when the line diameter of the O-ring 35 is d as in the second embodiment described above. It is preferable.

Moreover, in 2nd Embodiment mentioned above, the aspect arrange | positioned at the substantially center part of the fluorescent lamp 12 in the state which the several O-ring 54 was in close contact is illustrated. However, variations of this are also acceptable. For example, some distance may be provided between adjacent O rings 54.

(Other Embodiments)

In addition, various modifications are permitted in the present invention. Some examples are:

(A) The structure of the some light control sheets 5-8 in each said embodiment is an illustration to the last, for example, another kind of light control sheet may be arrange | positioned. Moreover, the change of the number of sheets of a light control sheet may also be performed suitably as needed. For example, one arrangement among the prism sheets 6 and 7 may be omitted.

(B) In each of the above embodiments, the light guide plate 4 has a wedge-shaped longitudinal cross-sectional shape. However, the present invention is not limited to this. For example, a light guide plate having a substantially uniform thickness may be employed, or a light guide plate having another cross-sectional shape may be used.

(C) In the above embodiment, the light source unit 11 is disposed only on the incident end surface 10 side of the light guide plate 4. However, the present invention is not limited to this.

For example, a plurality of incidence end surfaces may be formed on the light guide plate, and a plurality of light source units may be formed corresponding to these.

As described above, in the surface light source device according to the present invention, by correcting the curvature deformation of the frame and the deflection of the reflector, the light control sheet can be prevented from being suppressed by the frame or the reflector and wrinkles are generated. It is possible to prevent the light of the fluorescent lamp from being incident from the emitting surface side of. As a result, luminance unevenness of the planar light emitted from the light guide plate is suppressed, thereby enabling uniform and bright surface illumination.

Moreover, in the image display apparatus which concerns on this invention, an image display panel is illuminated by the illumination light of uniform and bright surface shape generate | occur | produced from the above-mentioned surface light source device. Thus, the image display quality of the image display panel is improved.

Claims (6)

A surface light source device in which light from a light source unit attached to a frame is emitted in a plane shape through a light guide plate and a light control sheet accommodated in the frame, The light source unit, A bar-shaped light source disposed to face the incident end surface of the light guide plate; A sheet metal processing reflector for accommodating the rod-shaped light source and guiding the light of the rod-shaped light source to the incident cross section of the light guide plate; And And a reflector support mounted to the frame while supporting the reflector, The reflector, It has a 1st plate-shaped part which adjoins the edge part of the exit surface of the said light incident plate side of the said light guide plate, and the 2nd plate-shaped part supported by the said reflector support body, And the second plate-shaped portion and the reflector support are positioned in engagement with the unevenness to position the surface light source device. A surface light source device in which light from a light source unit attached to a frame is emitted in a plane shape through a light guide plate and a light control sheet accommodated in the frame, The light source unit, A bar-shaped light source disposed to face the incident end surface of the light guide plate; A sheet metal processing reflector for accommodating the rod-shaped light source and guiding the light of the rod-shaped light source to the incident cross section of the light guide plate; And And a reflector support mounted to the frame while supporting the reflector, At least one pair of annular members are fitted to the rod light source, and a plurality of annular members are fitted between the pair of annular members adjacent to each other in close proximity to each other. And the rod-shaped light source is supported in the reflector through the annular member. A surface light source device in which light from a light source unit attached to a frame is emitted in a plane shape through a light guide plate and a light control sheet accommodated in the frame. The light source unit, A bar-shaped light source disposed to face the incident end surface of the light guide plate; A sheet metal processing reflector for accommodating the rod-shaped light source and guiding the light of the rod-shaped light source to the incident cross section of the light guide plate; And And a reflector support mounted to the frame while supporting the reflector, At least one pair of annular members are fitted to the rod-shaped light source, and an approximately cylindrical elastic member is fitted between the pair of annular members, And the rod-shaped light source is supported in the reflector through the annular member and the substantially cylindrical elastic member. A surface light source device in which light from a light source unit attached to a frame is emitted in a plane shape through a light guide plate and a light control sheet accommodated in the frame, The light source unit, A bar-shaped light source disposed to face the incident end surface of the light guide plate; A sheet metal processing reflector for accommodating the rod-shaped light source and guiding the light of the rod-shaped light source to the incident cross section of the light guide plate; And And a reflector support mounted to the frame while supporting the reflector, And a hook formed on the reflector supporter engaged with the concave-convex surface with respect to one side positioned on the side where the light source unit of the frame is mounted. 4. The surface light source according to claim 1, 2 or 3, wherein a hook formed on the reflector support is engaged with irregularities with respect to one side of the frame located on the side where the light source unit is mounted. Device. An image display device comprising the surface light source device according to any one of claims 1 to 5, and an image display panel illuminated with light emitted from the surface light source device.