JP4069631B2 - Backlight unit assembly method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an assembling method and structure of a backlight unit of a display device having a liquid crystal screen.
[0002]
[Prior art]
[0003]
[Problems to be solved by the invention]
A backlight provided behind the liquid crystal panel is used to illuminate the liquid crystal display in a dark place. This backlight is generally assembled as an integrated product (backlight unit) including a light guide plate and a sidelight type lamp.
[0004]
Since the characteristics of the backlight are greatly affected by the absolute arrangement or relative positional relationship of components such as the light guide plate, it is necessary to perform accurate positioning during assembly. For example, by providing the light guide plate with a mechanism that engages with the reflector, the positional relationship between the two can be accurately adjusted. In particular, when the reflector also serves as the casing of the backlight unit, positioning of the lamp can be performed, and variation in performance of each product can be reduced.
[0005]
However, as liquid crystal display devices become lighter as in recent years, backlight units are also required to be thinner and smaller, and as a result, materials used for reflectors must be soft and lighter.
[0006]
Accordingly, the present inventor has devised a backlight unit that can be slidably inserted into and removed from the apparatus body in pursuit of maintenance work such as lamp replacement. In this slide-type backlight unit, a light guide plate is inserted and removed as a framework so that the reflector is slid on a flat surface. Therefore, a thin sheet-like reflector is adopted in consideration of its slipperiness and lightness.
[0007]
However, if the light guide plate is provided with protrusions, etc., and the protrusions are inserted into the holes provided in the reflector and aligned to assemble the backlight unit, the lamp light travels through the protrusions of the light guide plate when the backlight is used. Leak outside. Therefore, the brightness of the backlight is sacrificed.
[0008]
The present invention has been made in view of such a problem, and an object thereof is to provide a method for easily assembling a slide detachable backlight unit.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing a backlight unit according to the present invention includes laying a sheet-like reflector having a hole through which the protruding claws are inserted on a jig having a plurality of protruding claws on the bottom surface. The light guide plate is placed on the reflector in a state where the projection claw is in contact with the side surface of the light guide plate by fitting the light guide plate with the projection claw inserted through the hole as a frame, and further on the side surface of the light guide plate. A light source is disposed oppositely, and a folding skirt around the reflector is folded so as to wrap the light source and bonded to the upper surface of the light guide plate, and then the jig is removed. By this method, it is possible to quickly perform accurate positioning only by placing the light guide plate with the projection claw inserted through the reflector as a frame.
[0010]
Specifically, in the method of manufacturing the backlight unit according to the present invention, a sheet-like reflector having a hole through which the projection claw is inserted is laid on a jig having projection claw at the four corners of the bottom, and the projection is inserted into the hole of the reflector. The light guide plate is placed on the reflector in a state in which the protrusion claw is in contact with the side surface of the light guide plate by fitting the light guide plate with the projected claw as a frame, and a light source is provided on the three side surfaces of the light guide plate. Are arranged opposite to each other, a holder is arranged on the remaining one side surface, the lead wire of the light source is guided along the guide groove, and the three-side folding wrap around the reflector is wrapped around so as to wrap the light source. The jig is bent into a letter shape and adhered to the upper surface of the light guide plate, and the remaining one side fold white is bent and adhered to the side surface of the holder, and then the jig is removed. According to this method, accurate positioning can be performed quickly only by placing the light guide plate with the projection claw inserted through the reflector as a frame.
[0011]
Then, the inclined sides are chamfered at the two corners of the light guide plate, the step portions are formed at the remaining two corners, and the pair of protruding claws and the inclined side are brought into contact with each other, and the remaining pair of the protrusions When the nail and the stepped portion are brought into contact with each other, the light guide plate can be easily fitted and the assembled backlight can be easily removed.
[0012]
Furthermore, if wall surfaces are provided on the three sides of the bottom surface of the jig on which the light sources are arranged to face each other, it is easy to bend the folding fold of the reflector, and the bent shape may be adjusted. In addition, it becomes easier to bend if a perforation is made at the folding position of the folding white.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 10 is a perspective view of the liquid crystal module 1 used in the display device as viewed from the front. The liquid crystal module 1 includes a liquid crystal panel 3 inside a frame 2 having a display window 2 a on the front surface, and the display surface of the liquid crystal panel 3 is exposed from the display window 2 a of the frame 2. The liquid crystal panel 3 is housed in a resin case 4. A cover 5 is attached around the frame body 2 to protect the frame body 2.
[0015]
FIG. 11 is a perspective view of the liquid crystal module 1 as viewed from the back, and shows a state where the cover 5 is removed. On the back side of the frame body 2, a flat plate-like rear metal fitting 6 is attached so as to have a gap with a predetermined thickness with the liquid crystal panel 3. A backlight unit 10 described later is detachably mounted in the gap.
[0016]
A substrate 7 on which various functional parts are mounted is screwed to the rear surface of the rear metal fitting 6. A connector 8 is provided on the back surface of the substrate 7 on the side of the insertion port 2b (see FIG. 13) of the backlight unit 10, and the connector 13 of the backlight unit 10 is detachably coupled to the connector 8. ing. Further, a shield 9 is screwed to the rear surface of the rear metal fitting 6 to protect a part of the substrate 7.
[0017]
FIG. 12 is a cross-sectional view of the entire liquid crystal module 1 (a) and the main part (b). In the resin case 4, three light control sheets 20 of a diffusion plate 21, a lens film 22, and a diffusion plate 23 are sequentially laminated on the back side of the liquid crystal panel 3. The light control sheet 20 may be two sheets, or may be a combination other than this. The light emitted from the light emitting surface of the backlight unit 10 becomes a surface light source having a more uniform luminance due to these light control sheets 20, and the display on the liquid crystal panel 3 is easy to see.
[0018]
Here, the reason why the light control sheet 20 is not integrally incorporated in the backlight unit 10 is that these parts are semi-permanently exchangeable parts, and the light guide plate 14 is used when the backlight unit 10 is inserted and removed. This is also for preventing damage caused by rubbing against the belt 20.
[0019]
FIG. 13 shows a state where the backlight unit 10 is extracted from the frame 2. The backlight unit 10 can be inserted / removed by sliding the reflector 15 on the sliding surface of the front surface of the rear metal fitting 6 from the insertion opening 2b of the frame 2 with a flat light guide plate 14 as a framework. When the backlight unit 10 is inserted and removed, the gap between the liquid crystal panel 3 and the rear metal fitting 6 is sealed by the backlight unit 10 itself, so that dust and dust do not easily enter the inside of the frame 2.
[0020]
Hereinafter, the structure of the backlight unit 10 will be described in detail. FIG. 1 is a perspective view when the backlight unit 10 is assembled, FIG. 2 is a perspective view from the front of the completed backlight unit, and FIG. 3 is a perspective view from the back.
[0021]
The light guide plate 14 is configured by using a light-transmitting, planar rectangular plate member such as acrylic, and has inclined sides 14c and 14d formed by chamfering at two adjacent corners 14a and 14b. These inclined sides 14c and 14d are formed to abut on the claws 33 and 34 of the jig 30, respectively. Further, at the other two adjacent corners 14x and 14y, step portions 14j and 14k parallel to the short side 14h are formed by notches. These step portions 14j and 14k are formed so as to be brought into contact with the claws 35 and 36 of the jig 30, respectively, and are recessed inward with a slight step from the short side 14h.
[0022]
The lamp 11 is formed of a cold cathode tube having a U-shaped planar shape arranged so as to face the three sides 14e, 14f, and 14g including the two corners 14a and 14b of the light guide plate 14. The lamp 11 is bent into an L shape corresponding to the corners 14a and 14b of the light guide plate 14 by providing a central straight portion 11a and left and right straight portions 11b and 11c at both ends thereof. Both ends of the lamp 11 are covered with a cap 19 made of silicon, and the two lead wires 12 and 12 are drawn out.
[0023]
As the light guide plate 14 and the lamp 11, those conventionally used as backlight components can be used as they are. Therefore, the backlight unit 10 can procure main components with inexpensive off-the-shelf products, and a rise in product price is suppressed.
[0024]
A holder 16 is provided on the short side 14h of the light guide plate 14 where the lamp 11 is not disposed. The holder 16 is a resin molded product having a dark color tone such as black or gray, and also plays a role of shielding light leaking from the light guide plate 14. A guide groove 16a of the lead wire 12 extends in the longitudinal direction of the holder 16, and the two lead wires 12 are guided so as not to slack over the groove 16a, and the light guide plate 14 is guided from the take-out groove 16b. Are bundled and connected to the connector 13.
[0025]
The holder 16 is integrally formed with a projection-shaped thin claw 18 made of the material resin of the holder 16. Further, a cylindrical screw receiver 17 is provided at the center of the holder 16. A screw groove into which a screw 24 (see FIG. 13) is screwed is formed on the inner surface of the screw receiver 17. Corresponding to this screw receiver 17, as shown in FIG. 13, the rear metal fitting 6 is provided with a circular screw holding portion 6 a for fixing the screw 24.
[0026]
Around the resin sheet reflector 15, as shown in the plan view of FIG. 4, there are provided folding whites 15a that are bent in a U shape on three sides facing the lamp 11, and the remaining one side. In addition, a folding white 15b that is bent into an L-shape is provided. These folding scissors 15a and 15b are provided with perforations 15c so as to be easily bent along the folding line. Note that the folding scissors 15b may be folded into a U shape according to the shape of the holder 16, or may be adhered to the holder 16 while being flat without being folded. In terms of strength, it is best to fold it into a U shape.
[0027]
The reflector 15 has inclined sides 15s and 15t formed by chamfering at two adjacent corners 15u and 15v. These inclined sides 15 s and 15 t can be confirmed by looking at the backlight unit 10 at a glance, so that they can also be used to confirm the front and back and the orientation of the backlight unit 10. Furthermore, small insertion holes 15j and 15k that are rectangular in the diagonal direction are formed in the corners 15u and 15v, respectively. These insertion holes 15j and 15k are provided to insert the claws 33 and 34 of the jig 30 in a direction perpendicular to the sliding direction of the backlight unit 10 (the direction of the arrow in FIG. 13). In addition, small rectangular insertion holes 15m and 15n are formed in the other two adjacent corners 15x and 15y. These insertion holes 15m and 15n are provided for inserting the claws 35 and 36 of the jig 30 in a direction perpendicular to the sliding direction of the backlight unit 10 (the direction of the arrow in FIG. 13).
[0028]
Further, the reflector 15 has a width corresponding to the length between the take-out grooves 16b and 16b of the holder 16, and is cut out in a rectangular shape from the folding scoop 15b to the lead wire 12 through the cutout portion 15d. It can be taken out on the back side. 15e and 15f are holes through which the screw receivers 17 and the claws 18 of the holder are inserted, respectively.
[0029]
The jig 30 used for assembling the backlight unit 10 is, for example, a thin plate product of a coated steel plate processed into a rectangle, and a wall surface 32 is integrated with the bottom surface 31 on the adjacent short side 30e and the long sides 30f, 30g. Is formed. Claws 33 and 34 are provided on the bottom surface 31 at a corner 30a where the short side 30e and the long side 30f intersect, and at a corner 30b where the short side 30e and the long side 30g intersect, respectively. Claws 35 and 36 are respectively provided on the bottom surface 31 at a corner 30c where the short side 30h and the long side 30f without the wall surface 32 intersect, and at a corner 30d where the short side 30h and the long side 30g intersect. These claws 33, 34, 35 and 36 can be easily formed by, for example, punching the bottom surface 31 into a U shape and raising it to the side where the wall surface 32 is located.
[0030]
The pair of claws 33 and 34 are not parallel to the short side 30e but are formed obliquely so as to have a predetermined angle. The angle coincides with the direction of the inclined sides 14 c and 14 d of the light guide plate 14. The remaining pair of claws 35 and 36 are provided in parallel to the short side 30h. A region on the bottom surface 31 surrounded by the four claws 33, 34, 35 and 36 defines a position on which the light guide plate 14 is placed, as shown in FIG. When the light guide plate 14 is thus arranged on the bottom surface 31 of the jig 30, as shown in FIG. 7A, the claws 33 and 34 and the inclined sides 14c and 14d come into contact with each other, and as shown in FIG. As described above, the stepped portions 14j and 14k abut on the claws 35 and 36.
[0031]
Hereinafter, an assembly procedure of the backlight unit 10 according to the present invention will be described with reference to FIG. First, the reflector 15 is laid on the bottom surface 31 of the jig 30. At this time, the claws 33, 34, 35 and 36 are inserted into the insertion holes 15j, 15k, 15m and 15n at the four corners of the reflector 15, respectively. Thereby, as shown in the cross-sectional view of FIG. 5, the folding scissors 15 a of the reflector 15 are bent along the inner surface of the wall surface 32 at the inner sewing surface 15 c. As described above, the wall surface 32 plays a role of making the folded shape 15a of the reflector 15 easier to bend into a U-shape and adjusting the folded shape.
[0032]
Then, after confirming the front and back of the light guide plate 14 so that the claws 33, 34, 35 and 36 are fitted in the frame, the claws 33, 34, 35 and 36 are placed on the reflector 15 straight. Thereby, the light guide plate 14 is arranged on the jig 30 without looseness, and accurate positioning is performed.
[0033]
Next, the lamp 11 is disposed so as to face the three sides 14e, 14f, and 14g of the light guide plate 14. At this time, considering the dimensional tolerance of the lamp 11, as shown in the cross-sectional view of FIG. 8, the lamp 11 is arranged in the approximate center of the space between the side surface of the light guide plate 14 and the folding white 15a of the reflector 15. To. Further, the holder is arranged at 16 along the short side 14 h of the light guide plate 14. At this time, the screw receiver 17 and the claw 18 are passed through the holes 15e and 15f of the reflector 15, respectively, the lead wire 12 is guided along the groove 16a and the extraction groove 16b, and the connector 13 is held on the back side of the light guide plate 14. come.
[0034]
Then, the folding scissors 15 a are folded at the outer perforations 15 c so as to wrap the lamp 11, and the folding scissors 15 b are folded into an L shape so as to be along the side surface of the holder 16. Finally, as shown in the cross-sectional view of FIG. 9, the inner surfaces of the folding scissors 15 a and 15 b are bonded to the upper surface of the light guide plate 14 and the side surface of the holder 16 with a double-sided tape 25, respectively. Thereby, the light guide plate 14, the lamp 11, and the holder 16 can be integrated only by the reflector 15. Further, since the easily breakable lamp 11 is protected by the reflector 15, the backlight unit 10 can be easily handled. If the jig 30 that is no longer needed is lifted slowly by the backlight unit 10, the claws 33, 34, 35, and 36 can be easily removed.
[0035]
When the completed backlight unit 10 is viewed from the rear side, the insertion holes 15j, 15k, 15m into which the claws 33, 34, 35 and 36 of the jig 30 are inserted at the four corners of the reflector 15 as shown in FIG. And 15n remain. However, since these are very small holes, there is no concern that light from the lamp 11 leaks, and the reflection efficiency of the reflector 15 is hardly hindered.
[0036]
In the above embodiment, the jig may be a plate material obtained by processing a wooden board or plywood instead of the steel sheet. And you may provide a pin as a protrusion for positioning instead of the said nail | claw on this board | plate material. A pin having a diameter of about 0.1 to 0.2 mm can be used. One pin or a plurality of pins may be provided corresponding to one nail. In the reflector 15, an insertion hole corresponding to the pin is formed.
[0037]
【The invention's effect】
As described above, according to the present invention, it is possible to easily and accurately assemble a detachable backlight unit that can be inserted into and removed from a display device using a light guide plate as a framework. The assembly of the backlight unit is very simple because only one jig is required and no special device is used. In addition, since the screws are not used to determine the positional relationship between the reflector and the light guide plate, the component cost is also reduced.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a backlight unit during assembly.
FIG. 2 is a front perspective view of the completed backlight unit.
FIG. 3 is a rear perspective view of the completed backlight unit.
FIG. 4 is a plan view of a reflector.
FIG. 5 is a cross-sectional view of the vicinity of a wall surface in a state where a reflector is laid on a jig.
FIG. 6 is a plan view showing a state in which a light guide plate is fitted using a jig projection claw as a frame.
7 is a perspective view of part A (a) and part B (b) in FIG. 6;
FIG. 8 is a cross-sectional view of the vicinity of a wall surface in a state where a reflector, a light guide plate, and a lamp are arranged on a jig.
FIG. 9 is a sectional view of the vicinity of a wall surface in a state where a backlight is completed on a jig.
FIG. 10 is a front perspective view of a liquid crystal module.
FIG. 11 is a rear perspective view of the liquid crystal module.
FIG. 12 is a cross-sectional view of the entire liquid crystal module (a) and a main part (b).
FIG. 13 is a perspective view of a state where a backlight unit is taken out from the liquid crystal module.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Liquid crystal module 10 Backlight unit 11 Lamp 12 Lead wire 14 Light guide plate 15 Reflector 15 Holder 30 Jig 31 Bottom surface 32 Wall surface 33, 34, 35, 36 Projection nail

Claims (4)

On a jig having a plurality of projections claws on the bottom, spread a sheet-like reflector having a hole in which the projection pawl is inserted, the protrusion claw inserted through the hole of the reflector by fitting the light guiding plate in the frame With the protruding claws in contact with the side surface of the light guide plate, place the light guide plate on the reflector, and further place a light source on the side surface of the light guide plate so as to wrap around the light source. A method of assembling a backlight unit, wherein the jig is removed after the white plate is bent and bonded to the upper surface of the light guide plate. On a jig having a projecting claw at the four corners of the bottom surface, laying a sheet-like reflector having a hole in which the projection pawl is inserted, the protrusion claw inserted through the hole of the reflector by fitting the light guiding plate in the frame With the protrusion claw in contact with the side surface of the light guide plate, place the light guide plate on the reflector, and further place a light source on the three side surfaces of the light guide plate, and a holder on the remaining one side surface. Guide the lead wire of the light source along the guide groove, fold the three-side fold whites around the reflector into a U shape so as to wrap the light source, and adhere to the upper surface of the light guide plate A method of assembling a backlight unit, comprising: bending a folding sword on one side and adhering to a side surface of the holder, and then removing the jig.  The light guide plate is formed with chamfered inclined sides at the two corners, and stepped portions are formed at the remaining two corners. The pair of protruding claws and the inclined side are brought into contact with each other, and the remaining pair of protruding claws The method of assembling a backlight unit according to claim 2, wherein the stepped portions are brought into contact with each other.  The bottom surface of the jig has a wall surface that makes it easy to bend the folding fold of the reflector on the three sides on which the light sources are opposed to each other, and adjusts the folded shape. A method for assembling the backlight unit as described.

Images