JP5556856B2 - Planar light source device and liquid crystal display device - Google Patents

Description

The present invention relates to a planar light source device including a light source device used for illumination of a display device or the like and a liquid crystal display device using the same .

  A general display device includes a display panel, a circuit board, a light source device, and the like. For the light source device that irradiates the display panel with light from the back side, the light source is disposed on the side surface of the casing (also referred to as an edge light type), or the light source is disposed on the bottom surface of the casing facing the display panel. There are direct type.

  Some sidelight type light source devices use a light guide plate to guide light from a light source to an opening of a housing. A light source device using a light guide plate propagates light emitted from a linear light source such as a cold cathode tube or a point light source such as a light emitting diode (hereinafter referred to as LED) within the light guide plate. Light is extracted in a planar shape at the opening of the housing by diffusing with a diffusion pattern provided in the optical plate.

  In a light source device using a point light source such as an LED as the light emitting element, when it is desired to increase the luminance of the display screen, the number of point light sources is increased to increase the element density, or the current supplied to each point light source is increased. It is possible to increase it. In any case, the peripheral portion of the point light source becomes hot due to the heat generated from each point light source with light emission.

  Therefore, a heat radiating means is provided on a light source substrate including a flexible printed circuit board (hereinafter referred to as FPC: Flexible Printed Circuit Board) on which a point light source is mounted and a wiring pattern for supplying power to each point light source is provided. A light source device has been proposed (for example, Patent Document 1 and Patent Document 2). The planar illumination device 1 disclosed in Patent Document 1 makes a heat transfer portion 10a provided in a recess 10 formed in a side wall 8 of a frame 6 made of a metal material and a mounting surface 3d of a point light source 3 contact each other. The point light source 3 is disposed in the recess 10 so that the FPC 4 as the light source substrate and the point light source 3 are fixed by the conductive adhesive 12. With this configuration, the heat generated with the light emission of the point light source 3 can be efficiently transferred by the metallic frame 6 and the heat dissipation can be improved. A technique is disclosed in which the supply current of each point light source 3 can be increased.

  Further, the backlight device disclosed in Patent Document 2 dissipates heat from the light-emitting diode 2 formed in the same shape as the film wiring substrate 4 on the surface opposite to the surface on which the light-emitting diode 2 of the film wiring substrate 4 is attached. A soft metal sheet 7 is attached with an adhesive and covered with a metal reflector 8. By comprising in this way, the heat | fever which generate | occur | produces in the light emitting diode 2 used as a light source does not remain in the backlight apparatus itself, but is effectively conducted to heat radiating members, such as the film wiring board 4 and the soft metal sheet 7, A technique of dissipating heat is disclosed.

However, in the light source devices disclosed in Patent Document 1 and Patent Document 2 described above, the light source substrate and the heat dissipation member are fixed with an adhesive, but the reliability problem such as the adhesive peeling off over time. was there.
Further, if a metal plate such as MCPCB (Metal Core Printed-Circuit Board) is used for the light source substrate in order to prevent the peeling, the cost becomes higher than that of the FPC.

JP-A-2006-210183 (page 2-5, Fig. 1-4) Japanese Patent Laid-Open No. 2002-229022 (page 3-7, FIG. 1-4)

  The present invention has been made to solve the above-described problems, and can efficiently dissipate heat generated from a light source substrate on which a point light source is directly mounted. (Partially deleted)

Surface light source device of the present invention, a back-frame data having a protrusion that protrudes toward the outside, a support member having an upper surface and a lower surface is fixed to the rear frame over arm, mounting the point light source is mounted A light source substrate having a surface and a rear surface fixed to the support member; a support portion facing part of the mounting surface; a side surface portion of the light source substrate; and a lower surface portion facing the upper surface of the support member; One of a front-frame data formed by the member, the support member so as to radiate heat generated by the point light sources on the rear frame side and a metal member, a support member fixed to the light source substrate, the front frame It is supported in the space formed by the support part, the lower surface part, and the protrusion part of the back frame.

  According to the planar light source device of the present invention, the heat generated from the light source substrate on which the point light source is directly mounted can be efficiently radiated.

It is a disassembled perspective view of the display apparatus in Embodiment 1 for implementing this invention. It is sectional drawing of the planar light source device seen from arrow AA direction when the display apparatus of FIG. 1 is assembled. It is a disassembled perspective view of the light source device in Embodiment 1 of this invention. It is a principal part enlarged view of the assembly state of the light source device in Embodiment 1 of this invention. It is sectional drawing seen from the arrow BB direction of the light source device of FIG. It is a principal part enlarged view of the light source device in Embodiment 1 of this invention. It is a disassembled perspective view of the planar light source device in Embodiment 1 of this invention. It is a principal part enlarged view of the light source device in Embodiment 1 of this invention. It is a principal part enlarged view of the light source device in Embodiment 1 of this invention. It is a principal part enlarged view of the light source device in Embodiment 1 of this invention. It is a disassembled perspective view of the display apparatus in Embodiment 2 of this invention. It is sectional drawing of the display apparatus seen from the arrow EE direction when the display apparatus of FIG. 11 is assembled.

Embodiments of the configuration and manufacturing method of a display device according to the present invention will be described below with reference to the drawings. In addition, what uses the same code | symbol in each figure shows the substantially same structure.
Embodiment 1 FIG.
FIG. 1 is an exploded perspective view showing a schematic configuration of a display device according to the present invention, and FIG. 2 is a cross-sectional view seen from the direction of arrows AA in the assembled state of the display device of FIG. 3 is an exploded perspective view showing a schematic configuration of a light source device mounted on the display device of the present invention, FIG. 4 is an enlarged view of a main part in a state where the light source device is assembled, and FIG. 5 is a view of the light source device of FIG. It is sectional drawing seen from the B direction.

Embodiment 1 FIG.
As shown in FIG. 1 or 2, reference numeral 1 denotes a box-shaped rear frame 1 having an opening 1 a, and a light source device 31 that emits light is disposed on an inner surface 1 b that is a side surface of the inner wall of the rear frame 1. Yes. On the bottom surface 1c of the inner wall of the back frame 1, a reflector 2 that directs the light emitted from the light source device 31 toward the opening 1a is disposed. In addition, a substantially rectangular light guide plate 7 for propagating light emitted from the light source device 31 in a planar shape is disposed inside the back frame 1 and is guided to a position facing the light emitting portion 31 a from which light is emitted from the light source device 31. An incident surface 7b that is one side surface of the optical plate 7 is disposed. Furthermore, the planar light source device 32 is configured by fitting the back frame 1 and the front frame 8 having an opening. On the emission surface side of the planar light source device 32, the display panel 9 and the circuit board 10 that drives and controls the display panel 9 are provided, and the front frame 11 having the opening 11 a and the planar light source device 32 are fitted. The display device 33 is configured.

Next, the light source device 31 of the first embodiment will be described in detail with reference to the drawings.
As described above, in FIG. 1, the light source device 31 is disposed on the inner surface 1 b of the back frame 1. As shown in FIGS. 3 and 4, the light source device 31 mounts the point light source 3 on the light source substrate 4 having a substantially rectangular shape, and the light source substrate cover 5 on the mounting surface 41 side of the point light source 3 of the light source substrate 4. The support member 6 is disposed at a position facing the rear surface 42 side. The point light source 3 is composed of a light emitting diode that emits light of red, green, blue, white, or an intermediate color thereof, and is singly or plurally arranged and mounted on the light source substrate 4 by soldering or the like. When a plurality of point light sources 3 are arranged, a color can be selected according to the application, or an appropriate color can be combined and mounted. Moreover, the space | interval between the point light sources 3, an arrangement position, etc. can be suitably arrange | positioned according to a use or the objective. In the first embodiment, a plurality of point light sources 3 are mounted on the light source substrate 4 in a substantially straight line at the same interval.

  As shown in FIGS. 2 to 4, the light source substrate 4 constituting the light source device 31 has a recess at a position where a projection 5 b provided on the light source substrate cover 5 described later overlaps with a recess 6 a provided on the support member 6. 4a is provided. The light source substrate 4 is made of a glass epoxy substrate, a metal base substrate, a flexible substrate, or the like, and a wiring pattern (not shown) for supplying power to the point light source 3 is provided on the light source substrate 4.

  As shown in FIGS. 2 to 5, the light source substrate cover 5 is arranged on the mounting surface 41 side of the point light source 3 of the light source substrate 4. A through hole 5a is provided at a position corresponding to the point light source 3 on the light source substrate 4 of the light source substrate cover 5, and a protrusion 5b protruding from the rear surface 52 on the upper surface 53 side and the lower surface 54 side between the through holes 5a. Is provided. As shown in FIG. 5, the protrusion 5 b has a structure in which a tip 5 c that fits into a recess 6 a provided in the support member 6 is provided. As shown in FIG. 2, the light source substrate cover 5 is formed thicker than the point light source 3 so that the point light source 3 mounted on the light source substrate 4 does not protrude from the through hole 5a. When the light source device 31 is incorporated into the display device 32 or when the light source device 31 is removed, it is possible to prevent the point light source 3 from coming into contact with the rear frame 1, the front frame 2, the light guide plate 7, etc. The through hole 5a may be a notch, and may have any shape as long as the light source is accommodated. The light source board cover 5 is made of a plastic resin, a metal, or a material containing a metal material. The light source substrate cover 5 may be formed of one member, or may be formed by combining a plurality of members as necessary. Further, the light source substrate cover 5 is desirably formed of a high light reflecting member such as a white or mirror surface in order to direct the light emitted from the point light source 3 toward the light guide plate 7.

  As shown in FIGS. 2 to 5, the support member 6 is formed to have the same size as or larger than the light source substrate 4, and is disposed on the rear surface 42 side of the light source substrate 4. Misalignment can be prevented. Further, the upper surface 61 and the lower surface 62 of the support member 6 are provided with a recess 6 a for fitting with the light source substrate cover 5. As shown in FIGS. 3 and 5, the concave portion 6 a forms a concave portion 6 a with different steps on the front surface 63 side and the rear surface 64 side, and the projection portion 5 b and the tip portion 5 c of the light source substrate cover 5 are supported by the support member 6. The rear surface 64 and the upper surface 61 are formed so as not to protrude. Further, the support member 6 may be formed of a plastic resin. However, the support member 6 is made of a metal having high thermal conductivity such as aluminum, stainless steel, iron, or copper, or a material containing these metals, thereby further enhancing the heat dissipation effect. be able to. Further, the support member 6 may be formed by a single member, or may be configured by combining a plurality of members.

Next, an assembling method of the light source device 31 will be described with reference to FIG.
First, the rear surface 42 of the light source substrate 4 on which the point light source 3 is mounted and the front surface 63 of the support member 6 are arranged so as to overlap each other. Furthermore, it arrange | positions so that the recessed part 4a of the light source substrate 4 and the recessed part 6a of the support member 6 may correspond. Next, the through hole 5a of the light source substrate cover 5 is disposed so as to be housed in the point light source 3, the protrusion 5b is made to coincide with the formation position of the recess 6a of the support member 6, and the protrusion 5b and the tip 5c are formed in the recess 6a. Mate. Here, in order to fix the light source substrate 4 to the support member 6, a double-sided tape, an adhesive, grease with high thermal conductivity, or the like may be used. In this case, the light source substrate 4 can be more closely attached to the support member 6 and the heat dissipation can be improved. Even if the pressure-sensitive adhesive deteriorates with the passage of time, the light source substrate 4 and the support member 6 can be firmly fixed by fitting and fixing the members to each other.

  As shown in FIGS. 3 and 5, in the light source device 31, the fitting portion formed by the protrusion 5 b of the light source substrate cover 5, the tip 5 c, the recess of the light source substrate 4, and the recess 6 a of the support member 6. Each member can be fixed by forming at least two places in each member, but four places, that is, two places on the upper surface (53, 61) side and two places on the lower surface (54, 62) side are provided. This makes it possible to secure each member.

  In the present embodiment, the projection 5b and the tip 5c provided for fitting on the light source board cover 5 side and the recess 6a provided for fitting on the support member 6 side are provided. It is good also as a structure which provides a recessed part in the cover 5 side, and provides a projection part and a front-end | tip part in the support member 6 side. Thus, the position and number of the fitting portions can be arbitrarily changed.

  Further, as shown in FIG. 6, the projection 5d for positioning is provided on the light source board cover 5, the positioning hole with the projection 5d is used for the light source board 4 (4b), and the fitting portion described above for the support member 6 (6b). It is provided separately and positioning is performed. By forming the positioning projections and positioning holes and performing positioning, the light source board cover 5, the light source board 4, and the support member 6 that are generated in the assembly process of the light source device 31, the assembly process of the display device 33, and the like. Misalignment can be prevented. Here, the light source substrate cover 5 is provided with protrusions, but the positions and shapes of the positioning protrusions and holes, such as provision of protrusions on the support member 6, can be changed as appropriate.

Next, a method for incorporating the light source device 31 of the first embodiment into the display device 33 will be described.
FIG. 7 is an enlarged view of a main part when the light source device 31 is incorporated into the planar light source device 32.
As described above, the light source device 31 sandwiches and supports the light source substrate 4 between the light source substrate cover 5 and the support member 6 so that the light source substrate 4 and the support member 6 are firmly fixed. It can be moved along the inner side surface 1b and incorporated. When incorporating into the inner side surface 1 b, the through-hole 12 for inserting the light source device 31 is formed on the side surface 1 d of the back frame 1 and the side surface of the front frame 8 constituting the planar light source device 32. Is moved in the direction of arrow C along the inner side surface 1b of the back frame 1. When the light source device 31 is defective and needs to be replaced, the light source device 31 can be easily removed by pulling the light source device 31 from the through-hole 12 and moving it in the direction of arrow D. In FIG. 1, in the case where the light source device 31 can also be replaced in the display device 33, a through hole is similarly formed in the front frame 11 at a position corresponding to the through hole 12.

  As described above, the light source device 31 according to the present invention includes the light source substrate 4 on which the point light source 3 is mounted, and the light source substrate cover 5 is provided on the light source substrate 4 on the mounting surface 41 side of the point light source 3. Since the support member 6 is disposed on the rear surface 42 side and the light source substrate 4 is sandwiched and supported by the light source substrate cover 5 and the support member 6, the light source substrate 4 can be prevented from being distorted or bent. The heat generated from the point light source 3 can be efficiently transferred to the support member 6. Further, the projection 5b and the tip 5c of the light source substrate cover 5 are made to coincide with the formation position of the recess 6a of the support member 6, the projection 5b and the tip 5c are fitted into the recess 6a, and each member is fixed. The light source substrate 4 and the support member 6 can be firmly fixed. Furthermore, since the light source device 31 can be inserted / removed from the through-hole 12 provided in the planar light source device 32, the light source device 31 can be easily replaced when a problem occurs.

  As a modification of the light source device 31 of the present embodiment, a tapered portion 5g is provided in the through hole 5a of the point light source 3 of the light source substrate cover 5, as shown in the enlarged view of the main part of FIG. The taper portion 5g is formed on the side surface of the inner wall forming the through hole 5a provided in the light source substrate cover 5 from the rear surface 52 that is the surface facing the mounting surface 41 of the light source substrate 4, and the front surface that is the surface opposite to the rear surface 52. As it goes to 51, the through hole 5 a is inclined so as to increase. When the light source device 31 provided with the taper portion 5g is incorporated in the display device 33 shown in FIG. 1, the light emitted from the point light source 3 is reflected by the taper portion 5g to be directed toward the light guide plate 7 side. Therefore, the reflection loss at the light source substrate cover 5 can be eliminated, and the light emitted from the point light source 3 can be efficiently incident on the light guide plate 7.

  As another modification of the light source device 31 of the present embodiment, a chamfered portion 5 f is formed at an end portion of the light source substrate cover 5 as shown in an enlarged view of a main part in FIG. 9. The chamfered portion 5f can improve workability by forming the light source device 31 at the end of the insertion start side when the light source device 31 is inserted from the through-hole 12. Further, as shown in FIG. 10, a convex portion 5e is provided at the end of the light source substrate cover 5 on the insertion end side of the light source device 31. By providing the protrusion 5 e, light leakage from the through-hole 12 can be prevented, and the light traveling toward the protrusion 5 e can be reflected and directed toward the light guide plate 7.

  In the present embodiment, the light source device 31 is disposed on one side of the inner side surface 1b of the back frame 1. However, by arranging the light source device 31 on two to four sides (not shown), the luminance is improved and the luminance is uniform. Can be realized.

  The back frame 1 is made of, for example, a metal having high thermal conductivity such as aluminum, stainless steel, iron, copper, or plastic resin. The back frame 1 may be configured as a single member, or may be configured by combining a plurality of members as necessary.

  The front frame 8 is made of, for example, a metal having high thermal conductivity such as aluminum, stainless steel, iron, copper, or plastic resin. The front frame 8 may be configured as a single member, or may be configured by combining a plurality of members as necessary.

  As the display panel 9, a liquid crystal display panel or the like is used. The liquid crystal display panel is composed of a pair of polarizing plates in which liquid crystal is injected between a pair of glass substrates and sealed with a sealing material, and is further bonded to upper and lower glass substrates. Further, the display panel 9 is connected to a circuit board 10 for driving and controlling the flexible board on which a driving IC chip or the like is mounted.

  Although not shown, between the display panel 9 and the light guide plate 7, in order to improve display performance, an optical sheet such as a diffusion sheet, a prism sheet, a polarization reflection sheet, or a plate-like light diffusion is used. A member is placed.

  As the material of the light guide plate 7, a highly transmissive material such as PMMA (Polymethylmethacrylate) or PC (Polycarbonate) is usually used. Moreover, in order to prevent deterioration of the light guide plate 7 due to the influence of heat generated from the point light source 3, particularly when used under high temperature conditions, a certain amount of distance between the point light source 3 and the light guide plate 7 can be secured. Although preferably, the distance between the point light source 3 and the light guide plate 7 is secured by making the thickness of the light source substrate cover 5 larger than the thickness of the point light source 3 as in the first embodiment. It becomes possible.

Embodiment 2. FIG.
FIG. 11 is an exploded perspective view of the display device according to Embodiment 2 of the present invention, and FIG. 12 is a partial cross-sectional view seen from the direction of arrows EE in the assembled state of the display device shown in FIG. As shown in FIGS. 11 and 12, in the light source device 34 of the second embodiment, the support member 6 is disposed on the rear surface 42 side of the light source substrate 4, but on the mounting surface 41 side of the point light source 3 of the light source substrate 4. The light source board cover 5 as in the first embodiment is not disposed, and the light source device 34 is fitted into the protrusion 1 f formed on the back frame 1 and the recess 8 b formed on the back frame 1 and the front frame 8. Thus, the light source substrate 4 and the support member 6 are supported. The only difference from the first embodiment is that the light source device 34 is fitted and supported in the protrusion 1f formed in the back frame 1 and the recess 8b formed in the back frame 1 and the front frame 8. The configuration is the same as that of the first embodiment.

  11 and 12, the bottom surface 1c facing the opening 1a of the back frame 1 includes a protruding portion 1f that includes one side of the bottom surface 1c and protrudes from the inside toward the outside. By fitting the light source device 34 to the inner wall of the protrusion 1f, the light source substrate 4 and the support member 6 are supported. At that time, the support member 6 is disposed to face the inner surface 1b of the back frame 1, and the mounting surface 41 of the light source substrate 4 is disposed to face the support portion 1e forming a part of the protruding portion 1f.

  Further, a concave portion 8b is formed by the inner side surface 1b of the back frame 1 and a part of the side surface 8a of the front frame 8 that has the side surface 8a that is oppositely disposed and is fitted to the inner side surface 1b of the back frame 1. Then, the light source device 34 is fitted into the recess 8b. The mounting surface 41 of the light source substrate 4 is arranged to face the support portion 8c formed in the recess 8b, and the light source substrate 4 and the support member 6 are fitted and supported together with the inner surface 1b of the back frame 1.

  In the method of incorporating the light source device 34 into the planar light source device 32 in the second embodiment, the light source device 34 is fitted to the inner wall of the protruding portion 1 f formed on a part of the bottom surface 1 c of the back frame 1. At that time, the support member 6 is disposed so as to face the inner surface 1 b of the back frame 1, and is disposed on the mounting surface 41 of the light source substrate 4 so as to face the support portion 1 e forming a part of the protruding portion. Next, after the reflection plate 2 and the light guide plate 7 are disposed, the front frame 8 is fitted to the back frame 1 and the light source device 34 is fitted to the recess 8b.

  As described above, the planar light source device 32 according to the second embodiment includes one side of the bottom surface 1c on the bottom surface 1c facing the opening 1a of the back frame 1, and protrudes from the inside to the outside. Since the portion 1f is formed in part and the light source device 34 is fitted to the inner wall of the protruding portion 1f and the recess 8b formed by the back frame 1 and the front frame 8, the light source substrate 4 and the support member 6 Can be firmly fixed.

  The protruding portion 1 f formed on the bottom surface 1 c of the back frame 1 may be provided along the light source substrate 4 or may be configured to support a part of the light source substrate 4. In the second embodiment, the light source device 34 is supported by being fitted in the protruding portion 1 f formed on the back frame 1 or the recessed portion 8 b formed by the back frame 1 and the front frame 8. Any shape can be used as long as the light source device can be fitted to the rear frame 1 and the front frame 8. Various changes such as the position where the recess 8b is formed can be made.

  In addition, the heat generated from the light source substrate 4 can be dissipated through the support member 6 by fixing the support member 6 to the back frame 1 using screws, an adhesive, or the like.

1 back frame, 2 reflector, 3 point light source, 4 light source board, 5 light source board cover,
5a Through hole, 5b Protruding part, 5c Tip part, 5d Protruding part for positioning, 5e Convex part, 5g Tapered part, 6 Support member, 6a Concave part, 7 Light guide plate, 7b Incident surface, 8 Front frame, 12 Through hole, DESCRIPTION OF SYMBOLS 31 Light source device, 32 Planar light source device, 1f Projection part, 8b Recessed part, 1e, 8c Support part, 11 Front frame, 11a Opening part, 33 Display apparatus.

Claims (14)

A back-frame data having a protrusion that protrudes toward the outside,
A support member having an upper surface and a lower surface is fixed to the rear frame over arm,
A light source substrate having a mounting surface on which a point light source is mounted and a rear surface fixed to the support member;
Supporting portion facing the portion of the mounting surface, and has a lower surface portion facing the upper surface of the side surface portion and the support member of the light source substrate, and a front-frame data formed by a single member ,
The support member is made of a metal member to dissipate heat generated by the point light source to the back frame side,
A planar light source device, wherein a support member to which the light source substrate is fixed is supported in a space formed by a support portion and a lower surface portion of the front frame and a protruding portion of the rear frame. The planar light source device according to claim 1, wherein an upper surface and a lower surface of the support member are fitted to face a lower surface portion of the front frame and a protruding portion of the rear frame, respectively. The planar light source device according to claim 1, wherein the protruding portion of the back frame supports a part of the light source substrate. 4. The support member according to claim 1, wherein the support member is fixed to the back frame by screwing or using an adhesive material, so that heat generated from the light source substrate is dissipated through the support member. The planar light source device according to claim 1. The planar light source device according to claim 1, wherein the point light source emits light in a normal direction of the light source substrate. The surface according to any one of claims 1 to 5, further comprising a light guide plate disposed so that an incident surface on which light from the point light source is incident faces a mounting surface of the light source substrate. Light source device. The planar light source device according to claim 1, wherein the support member has the same size as the light source substrate or a size larger than the same size. The planar light source device according to any one of claims 1 to 7, wherein the metal member constituting the support member is formed of any one of aluminum, stainless steel, iron, and copper. Wherein the light source substrate and the support member, both sides tape, adhesives, or surface light source device according to any one of claims 1 to 8, characterized in that it is fixed by the grease. The planar light source device according to claim 1, wherein the support member has a positioning protrusion or a positioning hole. The rear frame over arm is aluminum, stainless steel, iron, copper or according to any one of claims 1 to 10, characterized in that it is constituted by a member made of any one or more of plastic resin, Planar light source device. The front frame over arm is aluminum, stainless steel, iron, copper or according to any one of claims 1 to 11, characterized in that it is constituted by a member made of any one or more of plastic resin, Planar light source device. The protrusion surface light source device according to any one of claims 1 to 12, characterized in that provided along the light source substrate. A surface light source device according to any one of claims 6 to 12,
A display panel placed on the front frame ,
The liquid crystal display device wherein an optical sheet over preparative or plate-like light diffusion member is disposed between the display panel and the light guide plate.

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