JP4441394B2 - Backlight device - Google Patents

Description

  The present invention relates to a backlight device, and more particularly to a backlight device that is easy to assemble.

  In recent years, display devices using liquid crystal cells are mounted on various electronic devices such as watches, telephones, and personal computers. In such an electronic device, in particular, a watch, a mobile phone, and the like are often used at night or in a dark place, and therefore, are often provided with a backlight for illuminating a liquid crystal cell. In this backlight, a light guide plate made of a transparent synthetic resin such as acrylic is disposed on the back surface side of the liquid crystal display element, and light from a light source disposed on the lower surface or end surface of the light guide plate is transmitted through the light guide plate to the liquid crystal display element. In the surface of the light guide plate on the liquid crystal display element side, at least one of the light diffusion sheets made of synthetic resin is laminated on the light diffusion sheet as necessary. Therefore, a prism sheet for increasing the brightness is laminated.

  In this case, at least one light diffusion sheet laminated on the light guide plate, or a sheet-like member such as a light diffusion sheet, a prism sheet, or the like is used in order to facilitate assembly to the liquid crystal display element, or It is fixed to a frame that houses the sheet-like member. A first conventional example of this fixing method is shown in FIG. 10A and 10B show the main part of the backlight device of the first conventional example. FIG. 10A is a plan view, and FIG. 10B is a cross-sectional view taken along line AA in FIG. As shown in FIG. 10, the backlight device of the first conventional example has two light diffusing sheets 2 on a step portion 8a of a frame body 8 holding a light guide plate 1, and a sheet such as a prism sheet 3 for increasing luminance. The sheet-like member is fixed to the frame 8 using the adhesive tape 9.

  A second conventional example is shown in FIG. 11A and 11B show the main part of the backlight device of the second conventional example. FIG. 11A is a plan view, and FIG. 11B is a cross-sectional view taken along line BB in FIG. As shown in FIG. 11, in the backlight device of the second conventional example, a plurality of pins 7 project integrally from a step portion 8 a of a frame 8 that holds the light guide plate 1. Further, holes 2 a and 3 a are provided in the two light diffusion sheets 2 and the prism sheet 3 so as to be fitted to the pins 7. Then, the holes 7 a and 3 a of the light diffusion sheet 2 and the prism sheet 3 are fitted to the pins 7 of the step portion 8 a of the frame body 8, and the light diffusion sheet 2 and the prism sheet 3 are stacked on the step portion 8 a of the frame body 8. To do. Thereafter, the tip of the pin 7 is heated and pressed in the axial direction, and the tip of the pin 7 is caulked and deformed into a flat shape to form the deformed portion 7a, thereby fixing the light diffusion sheet 2 and the prism sheet 3 to the frame body 8. is doing.

  A third conventional example is shown in FIG. FIG. 12 is a cross-sectional view showing a main part of a backlight device of a third conventional example. As shown in FIG. 12, the backlight device of the third conventional example includes, in the surface of the light guide plate 1, pins 5 configured in a tapered shape at two portions along one side surface of the light guide plate 1. While projecting integrally, holes 2a and 3a into which the two pins 5 of the light diffusion sheet 2 and the prism sheet 3 are fitted are formed. And after laminating | stacking the light diffusion sheet 2 and the prism sheet 3 on the surface of the light-guide plate 1 so that the pin 5 may fit in each hole 2a, 3a drilled in this, on the front-end | tip of the pin 5, A horn 6 for ultrasonic welding is brought into contact and pressed in the axial direction with ultrasonic vibration applied. As a result, the tapered tip of the pin 5 is melted before the base portion of the pin 5 with respect to the light guide plate 1, and is caulked and deformed in a flat shape (the caulked deformed portion is indicated by reference numeral 5a). Various sheets 2 and 3 are fixed to the light guide plate 1. (For example, refer to Patent Document 1.)

Japanese Patent Laid-Open No. 2002-318386 (page 3, FIG. 4)

However, in the backlight device according to the first prior art described above, it is necessary to separately prepare a fastening member such as the window frame-shaped adhesive tape 9 and the price of the window frame-shaped adhesive tape 9 is expensive. . In addition, poor adhesion may occur in the bonding process. In this case, when the adhesive tape 9 is peeled off for correction, sheet-like members such as the light diffusing sheet 2 and the prism sheet 3 are peeled off together, resulting in scratches and dirt. Often discarded as good. For this reason, there is a problem that the cost required for fixing the sheath and the shaped member, and consequently the cost required for manufacturing the backlight device, is increased.
Further, in the backlight devices in the second and third prior arts, there is a case where a caulking defect occurs in the caulking fixing process. In this case, the parts cannot be regenerated, and all the parts become defective. Must be discarded. In the caulking process, dedicated equipment is required. For this reason, there has been a problem in that the cost required for manufacturing the backlight device increases as in the first prior art.

(Object of invention)
The object of the present invention is to solve the above-mentioned problems in the prior art, improve the assemblability, facilitate the assembly, eliminate the defective parts caused by poor adhesion, caulking, etc. in the assembling process, and provide an inexpensive backlight device. There is to do.

  In order to achieve the above object, the backlight device of the present invention includes a frame, a light guide plate held by the frame, a light diffusion sheet disposed on the upper surface side of the light guide plate, and a sheet shape such as a prism sheet. In the backlight device including the member, the frame body includes a frame main body that houses the light guide plate and the sheet-like member, and a substantially U-shaped fixed frame that is detachably coupled to the frame main body. The frame body has two side walls facing each other and through holes penetrating in the thickness direction in each of the two side walls, and the fixed frame has coupling protrusions coupled to the through holes and coupled to the through holes. By locking the protrusion, the fixed frame is coupled to the frame body, and the light guide plate and the sheet-like member are held on the frame.

  The frame body includes a frame main body and two fixed frames. The through holes provided in the frame main body are provided in the vicinity of both ends of the two side walls, have recesses on the inner surfaces, and the two fixed frames are plates. Each of the plate-like members and the leg portions provided on both ends of the plate-like member, and the coupling protrusions provided on the inner ends of the respective leg portions, and the two fixing frames are arranged near both ends of the two side walls. The sheet frame member is sandwiched between the light guide plate and the fixed frame, and the fixed frame is coupled to the frame main body by hook coupling the concave portion of the through hole of the frame main body and the coupling protrusion of the fixed frame. Features.

  Further, the frame body has a U-shaped planar shape with one side of the frame-shaped body opened, a groove provided over the entire length of each inner wall of the two side walls, and an end portion where the two side walls are opened. The fixing frame includes a plate-like member, four leg portions provided at each of the four corners of the plate-like member, and a coupling protrusion provided at the tip of each of the four leg portions. After the light guide plate and the sheet-like member are inserted and arranged in the groove, the fixed frame is brought into contact with the open ends of the two side walls, and the through hole of the frame body and the coupling protrusion of the fixed frame are hook-coupled The fixed frame is combined with the frame main body.

  As described above, in the backlight device of the present invention, a fixed frame that is separable from the frame main body is coupled to the frame main body in which sheet-like members such as the light guide plate and the light diffusion sheet 2 and the prism sheet 3 are housed. By adopting the configuration in which the light guide plate and the sheet-like member are held in the body, it is possible to eliminate the adhesion failure and the caulking failure that occur in the process of holding the sheet-like member in the frame. Further, it is not necessary to prepare a separate fastening member such as an adhesive tape, and no dedicated equipment for the caulking process is required. As a result, it is possible to improve the assembling property, facilitate the assembling, eliminate the defective parts in the assembling process, and provide an inexpensive backlight device.

A backlight device according to an embodiment of the present invention includes a frame, a light guide plate held by the frame, and a sheet-like member such as a light diffusion sheet and a prism sheet disposed on the upper surface side of the light guide plate. ing. The frame body includes a frame main body that houses the light guide plate and the sheet-like member, and a substantially U-shaped fixed frame that is detachably coupled to the frame main body, and faces the frame main body. A through hole penetrating in the thickness direction is formed in each of the two side walls. Further, the fixed frame is formed with a coupling projection portion that is coupled to a through hole provided in the frame body, and the coupling projection portion is locked to the through hole, thereby coupling the fixed frame to the frame body and the light guide plate to the frame body. And it is comprised so that a sheet-like member may be hold | maintained. As described above, the backlight device according to the embodiment of the present invention is characterized by the structure of the frame, and the other structure is similar to the backlight device in the prior art. Therefore, the configuration of the frame will be described in detail, and the same numbers will be assigned to other components similar to those in the conventional example, and description thereof will be omitted.
Hereinafter, specific examples in the embodiment of the present invention will be described in detail with reference to FIGS. 1 to 9. 1 to 4 show the frame of the backlight device in Example 1 of the present embodiment, and FIGS. 5 to 9 are diagrams showing the frame of the backlight device in Example 2. FIG.

  The frame of the backlight device according to the first embodiment will be described with reference to FIGS. 1 is an exploded perspective view showing a frame body of a backlight device according to Embodiment 1, FIG. 2 is a partially enlarged view of a frame body, FIG. 2 (a) is a perspective view, and FIG. 2 (b) is FIG. 2 (a). It is CC sectional drawing in FIG. 3 is a perspective view showing the fixed frame, FIG. 4 shows a frame body in which the frame main body and the fixed frame are combined, FIG. 4A is a perspective view, and FIG. 4B is FIG. It is DD sectional drawing in). Hereinafter, the frame of the backlight device according to the first embodiment will be described with reference to the drawings.

  As shown in FIG. 1, the frame 10 of the backlight device in this example is separable from the frame main body 10b that houses the light guide plate 1 and sheet-like members such as the light diffusion sheet 2 and the prism sheet 3, and the frame main body 10b. It consists of two fixed frames 10a to be joined. The frame body 10b has a frame shape having side walls 18a, 18b, 18c, and 18d, and the light guide plate 1, the light diffusion sheet 2, the prism sheet 3 and the like are stacked and accommodated inside the frame body 10b. It has become. Further, step portions 15a and 15b are formed inside the two side walls 18a and 18b facing each other, and the step portions 15a and 15b are penetrated in the thickness direction in the vicinity of both ends, and openings are formed. Through holes 16a, 16b, 16c, and 16d having a substantially rectangular shape are provided.

  Further, as shown in FIG. 2, the through holes 16a and 16b provided in the vicinity of one end of the step portions 15a and 15b are provided with recesses 17a and 17b on the inner surfaces facing the inner sides of the side walls 18a and 18b. . Since the frame main body 10b is manufactured by molding, the recesses 17a and 17b are preferably opened on the lower surfaces of the step portions 15a and 15b, and are also preferable in terms of thickness reduction. Although not shown in the drawing, recesses are similarly provided on the inner surfaces of the respective through holes 16c and 16d provided in the vicinity of the other ends of the step portions 15a and 15b.

  On the other hand, as shown in FIG. 3, the fixed frame 10a has a substantially U-shape having leg portions 12a and 12b at both ends of the plate-like member 11, and extends inwardly from the tips of the leg portions 12a and 12b. Coupling projections 13a and 13b projecting toward the top are formed.

  Next, a method of holding the light guide plate 1, the light diffusion sheet 2, and the prism sheet 3 on the frame body 10 by combining the frame body 10 b and the fixed frame 10 a will be described. In FIG. 1, the light guide plate 1 is disposed inside the frame body 10b. Although not shown, at this time, the light guide plate 1 is held at a predetermined position by a known method such as hook coupling to the frame body 10b. Next, the two light diffusion sheets 2 and the prism sheet 3 are sequentially stacked. Thereafter, the two fixed frames 10a are disposed above both ends of the two side walls 18a and 18b, and the leg portions 12a and 12b of the fixed frame 10a are opposed to the step portions 15a and 15b of the frame body 10b. Then, the leg portions 12a and 12b of the one fixed frame 10a are inserted into the through holes 16a and 16b provided in the vicinity of one end of the step portions 15a and 15b in the side walls 18a and 18b, respectively. Further, the leg portions 12a and 12b of the other fixed frame 10a are inserted into the through holes 16c and 16d provided near the other ends of the step portions 15a and 15b, respectively.

  Further, when one fixed frame 10a is pressed from above, as shown in FIG. 4, the recesses 17a and 17b provided in the through holes 16a and 16b, and the coupling protrusions provided at the tips of the leg portions 12a and 12b of the one fixed frame 10a One fixed frame 10a is coupled to the frame body 10b by hook coupling the portions 13a and 13b. Similarly, a recess (not shown) provided in the through holes 16c and 16d by pressing the other fixed frame 10a from above and the coupling protrusions 13a and 13b of the other fixed frame 10a are hook-coupled to the frame body 10b. The other fixed frame 10a is joined. As a result, the light diffusion sheet 2 and the prism sheet 3 are held between the light guide plate 1 and the fixed frame 10 a, and sheet-like members such as the light diffusion sheet 2 and the prism sheet 3 are held by the frame body 10.

  When the coupling between the frame main body 10b and the one fixed frame 10a is released, the through holes 16a and 16b are provided from the openings of the through holes 16a and 16b on the lower surface side of the frame main body 10b using tools such as tweezers. Hook coupling between the recesses 17a and 17b and the coupling protrusions 13a and 13b of the fixed frame 10a is released. As described above, since the lower surfaces of the recesses 17a and 17b are opened, the hook connection can be easily released. Thus, it is preferable to open the lower surfaces of the recesses 17a and 17b in order to release the hook connection. Similarly, the other fixed frame 10a can be released from the coupling. Thereby, the coupling between the frame main body 10b and the fixed frame 10a can be released and separated.

  As described above, the backlight device according to the present embodiment hooks the fixed frame 10a to the frame main body 10b, and holds the sheet-like members such as the light diffusion sheet 2 and the prism sheet 3 on the frame 10, so that the conventional example is used. Such adhesion failure and caulking failure do not occur. Moreover, there is no need to prepare a separate engaging member, and no dedicated equipment is required. As a result, it is possible to improve the assembling property, facilitate the assembling, eliminate the defective parts in the assembling process, and provide an inexpensive backlight device. Further, since both the frame body 10b and the fixed frame 10a are manufactured by molding, the frame body 10 in which the frame body 10b and the fixed frame 10a are coupled has excellent mechanical strength and is resistant to external impact. Has sufficient strength. For this reason, the light guide plate 1, the light diffusion sheet 2, the prism sheet 3, and the like can be reliably held.

  Next, the frame of the backlight device according to the second embodiment will be described with reference to FIGS. FIG. 5 is an exploded perspective view showing a frame of the backlight device according to the second embodiment, FIG. 6 is a partially enlarged view of the frame main body, FIG. 6 (a) is a perspective view, and FIG. 6 (b) is in FIG. EE sectional drawing, FIG.6 (c) is FF sectional drawing in Fig.6 (a). 7 shows a fixed frame, FIG. 7 (a) is a perspective view, and FIG. 7 (b) is a side view. 8 shows a frame body in which the frame main body and the fixed frame are combined, FIG. 8 (a) is a perspective view, FIG. 8 (b) is a cross-sectional view along GG in FIG. 8 (a), and FIG. FIG. 8A is a cross-sectional view taken along the line H-H, and FIG. 9B is a cross-sectional view taken along the line KK in FIG. Hereinafter, the frame of the backlight device according to the second embodiment will be described with reference to the drawings.

As shown in FIG. 5, the frame body 20 of the backlight device in this example is separable from the frame body 20 b that houses the light guide plate 1 and sheet-like members such as the light diffusion sheet 2 and the prism sheet 3, and the frame body 20 b. It is comprised with the fixed frame 20a couple | bonded. As shown in FIG. 6, the frame main body 20b has three side walls 28a, 28b, and 28c, and has a U-shaped planar shape in which one side of the frame-shaped body is opened. Further, step portions 25a and 25b are formed inside the two side walls 28a and 28b facing each other, and grooves 27a and 27b extending in the longitudinal direction are formed on the inner walls of the step portions 25a and 25b, respectively. It is formed over. Furthermore, through-holes 26a and 26b are formed in the step portions 25a and 25b located in the vicinity of the opened ends of the two side walls 28a and 28b in the thickness direction, and the openings have a substantially rectangular shape. It has been.

  On the other hand, as shown in FIG. 7, the fixed frame 20a has a substantially U-shape having four leg portions 22a, 22b, 22c and 22d at each of the four corners of the plate-like member 21, and the four leg portions 22a. , 22b, 22c, and 22d are formed with coupling protrusions 23a, 23b23a, and 23b that project inward from the respective tips.

  Next, a method for holding the light guide plate 1, the light diffusion sheet 2, and the prism sheet 3 on the frame body 20 by combining the frame body 20 b and the fixed frame 20 a will be described. In FIG. 5, the light guide plate 1, the light diffusion sheet 2, and the prism sheet 3 are stacked and inserted into the frame body from the opening side of the frame body 20 b. At this time, both ends of the light guide plate 1, the light diffusion sheet 2, and the prism sheet 3 are inserted into the grooves 27a and 27b provided on the inner walls of the step portions 25a and 25b of the two side walls 28a and 28b of the frame body 20b. And placed at a predetermined position.

  Next, the fixed frame 20a is arranged on the open end side of the two side walls 28a, 28b of the frame main body 20b, and the leg portions 22a, 22b provided at one end of the fixed frame 20a are provided with the step portions 25a of the frame main body 20b. The leg portions 22c and 22d provided at the other end of the fixed frame 20a are opposed to the step portion 25b of the frame main body 20b. Then, the fixed frame 20a is moved in the direction of the frame body 20b so that the step portion 25a is sandwiched in the thickness direction by the leg portions 22a and 22b, and the step portion 25b is sandwiched in the thickness direction by the leg portions 22c and 22d.

  Further, the fixed frame 20a is pressed, and the plate-like member 21 of the fixed frame 20a is brought into contact with the open ends of the two side walls 28a, 28b of the frame main body 20b as shown in FIGS. The upper and lower openings of the through-hole 26a provided in the upper portion and the coupling protrusions 23a and 23b provided at the tips of the legs 22a and 22b of the fixing frame 20a are hook-coupled to fix the upper and lower openings of the through-hole 26b provided in the side wall 28b. The coupling protrusions 23c and 23d provided at the tips of the leg portions 22c and 22d of the frame 20a are hook-coupled to couple the fixed frame 20a to the frame body 20b. As a result, the light guide plate 1, the light diffusion sheet 2, and the prism sheet 3 are held by the frame body 20.

  When releasing the coupling between the frame main body 20b and the fixed frame 20a, a tool such as tweezers is inserted into the gap between the through hole 26a and the coupling protrusion 23a of the frame main body 20b, and the through hole 26a and the coupling protrusion 23a are inserted. Release the hook connection. Similarly, the hook coupling between the other three through holes and the coupling protrusion is released. Thereby, the coupling between the frame body 20b and the fixed frame 20a can be released and separated.

  As described above, according to the backlight device in the present embodiment, as in the first embodiment, the assembling property is improved, the assembly is facilitated, and the component defect in the assembly process is eliminated, thereby providing an inexpensive backlight device. be able to. In addition, the light guide plate 1, the light diffusion sheet 2, the prism sheet 3, and the like can be reliably held.

It is a disassembled perspective view which shows the frame of the backlight apparatus in Example 1 of this invention. FIG. 2A is a partial enlarged view of a frame main body according to the first embodiment of the present invention, FIG. 2A is a perspective view, and FIG. 2B is a cross-sectional view taken along a line CC in FIG. It is a perspective view which shows the fixed frame in Example 1 of this invention. The frame in Example 1 of this invention is shown, Fig.4 (a) is a perspective view, FIG.4 (b) is DD sectional drawing in Fig.4 (a). It is a disassembled perspective view which shows the frame of the backlight apparatus in Example 2 of this invention. FIG. 6 (a) is a perspective view, FIG. 6 (b) is a cross-sectional view taken along line EE in FIG. 6 (a), and FIG. 6 (c) is FIG. It is FF sectional drawing in (a). The fixed frame in Example 2 of this invention is shown, Fig.7 (a) is a perspective view, FIG.7 (b) is a side view. The frame in Example 2 of this invention is shown, Fig.8 (a) is a perspective view, FIG.8 (b) is GG sectional drawing in Fig.8 (a). FIG. 9A is a cross-sectional view taken along the line H-H in FIG. 8A, and FIG. 9B is a cross-sectional view taken along the line KK in FIG. 8A. The principal part of the backlight device in the first conventional example is shown, FIG. 10A is a plan view, and FIG. 10B is an AA cross-sectional view in FIG. FIG. 11A is a plan view, and FIG. 11B is a cross-sectional view taken along line BB in FIG. 11A, showing the main part of a backlight device in a second conventional example. It is a partial expanded sectional view which shows the principal part of the backlight apparatus in a 3rd prior art example.

Explanation of symbols

1
Light guide plate 2
Light diffusion sheet 2a hole 3
Prism sheet 3a hole
5, 7 Pins 5a, 7a Caulking deformation part 6 Ultrasonic welding horn 8 Frame 8a Step 9 Adhesive tape 10 Frame 10a Fixing frame 10b Frame body 11 Plate-like members 12a, 12b Legs 13a, 13b Coupling protrusions 15a, 15b Stepped portions 16a, 16b, 16c, 16d Through holes 17a, 17b Recessed portions 18a, 18b Side wall 20 Frame body 20a Fixed frame 20b Frame body 21 Plate members 22a, 22b, 22c, 22d Leg portions 23a, 23b, 23c, 23d Coupling protrusions 25a, 25b Steps 26a, 26b Through holes 27a, 27b Recesses 28a, 28b Side walls

Claims (3)

In a backlight device comprising a frame, a light guide plate held by the frame, and a sheet-like member such as a light diffusion sheet and a prism sheet disposed on the upper surface side of the light guide plate,
The frame body includes a frame main body that houses the light guide plate and the sheet-like member, and a substantially U-shaped fixed frame that is detachably coupled to the frame main body, and the frame main bodies face each other. There are two side walls and a through-hole penetrating in the thickness direction in each of the two side walls, the fixing frame has a coupling projection part coupled to the through-hole, and the coupling projection part is engaged with the through-hole. The backlight device is characterized in that the fixed frame is coupled to the frame body by being stopped, and the light guide plate and the sheet-like member are held on the frame body.   The frame body includes the frame main body and the two fixed frames, and through holes provided in the frame main body are provided near both ends of the two side walls, and have recesses on the inner surfaces thereof. The fixed frame includes a plate-like member, leg portions provided on both ends of the plate-like member, and a coupling protrusion provided on the inside of the tip of each leg portion, and the two fixed frames are attached to the two side walls. By placing the sheet-like member between the light guide plate and the fixed frame, and hooking the concave portion of the through hole of the frame body and the coupling protrusion of the fixed frame, respectively, arranged near both ends. The backlight device according to claim 1, wherein the fixed frame is coupled to the frame body. The frame main body has a U-shaped planar shape in which one side of the frame-shaped body is opened, a groove provided over the entire inner wall of each of the two side walls, and an open end of the two side walls. The fixing frame is provided with plate holes, four leg portions provided at the four corners of the plate member, and coupling protrusions provided at the tips of the four leg portions, respectively. After the light guide plate and the sheet-like member are inserted and disposed in the groove, the fixed frame is brought into contact with the open end portions of the two side walls, and the through hole of the frame body and the fixed The backlight device according to claim 1, wherein the fixed frame is coupled to the frame main body by hook coupling with a coupling projection of the frame.

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