JP2008257952A - Backlight device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backlight device capable of preventing foreign material such as dust from leaking in the device while solving a problem of interference caused by expansion and contraction of a light guide plate and optical sheets. <P>SOLUTION: The backlight device comprises a support plate 10, the light guide plate 30 arranged on a front side of the support plate 10 for emitting light from the light source introduced from an end surface to a front surface, and the optical sheets 40, 50, 51 arranged on a front side of the light guide plate. The backlight device further includes a holding member 60 mounted on an upper end part of the support plate 10 and having a holding part on a lower surface side. The light guide plate 30 includes a projection 34 projecting to a rear surface side and formed on an upper end part, and a step 35 formed on an edge part of an upper end surface. The support plate 10 includes a receiving seat 11 in a position corresponding to a rib 34. In mounting the holding member 60, the rib 34 is sandwiched vertically by the holding part and the receiving seat, and the light guide plate 30 is held by the support plate 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The backlight of the liquid crystal display device is roughly classified into an edge light method and a direct type, but the edge light method is mainstream in a relatively small liquid crystal display device used for a car navigation device, a cellular phone, or the like. In the edge light type backlight device, light introduced into the light guide through the end face is emitted from the front of the light guide, and then the light beam is adjusted through the optical sheet to obtain desired planar light. The light guide plate and the optical sheet are fixed (held) to a support plate or a housing (hereinafter referred to as “support plate”). As a method for fixing the light guide plate or the like in the conventional backlight device, rubber or the like is used. A method of fixing a light guide plate or the like to a support plate or the like using a cushioning component, forming a concave portion of a predetermined shape on the support plate or the like, forming a light guide plate or the like into a shape corresponding to the concave portion, And the like (Patent Document 1) and the like have been employed. In addition, a method of fixing the light guide plate and the like to the support plate by screwing has been proposed (Patent Document 2).
JP 2000-30519 A Japanese Patent Laid-Open No. 9-90361

In a relatively small liquid crystal display device used for a car navigation system or the like, the size of the liquid crystal display device is being increased in order to improve the visibility, to increase the amount of information that can be displayed, or to expand applications. If the liquid crystal display device is increased in size, the light guide plate and the optical sheet necessary for the backlight used for the liquid crystal display device are also increased in size. However, in a backlight using such a large light guide plate and optical sheet, expansion and contraction of the light guide plate and the optical sheet becomes a problem when used in an environment with a large temperature difference such as in an automobile. That is, if a large-sized light guide plate and optical sheet are used, the problem that these members expand and interfere with each other, or interfere with surrounding members such as a support plate, becomes obvious. It is necessary to take appropriate measures. Here, in a liquid crystal display device used in an automobile, it is necessary to make a support plate or the like made of metal in order to prevent electromagnetic induction interference. However, when a metal support plate or the like is used, the above-described problem becomes more conspicuous because the difference in coefficient of thermal expansion between the light guide plate and the optical sheet is large. Although it is conceivable to increase the clearance between the members as a measure for solving the problem of interference, it is not appropriate because foreign matters such as dust easily enter as the clearance increases. The intrusion of foreign matter affects the optical characteristics of the backlight device, and causes the generation of turbulent light and a decrease in luminance.
On the other hand, a backlight used in an environment with a lot of vibration such as in an automobile is required to prevent rattling of the light guide plate that causes abnormal noise.
In view of the above points, the present invention eliminates the problem of interference caused by the expansion and contraction of the light guide and the optical sheet in the backlight device, and prevents foreign matters such as dust from entering the device. Let it be the first problem. Another object is to prevent the light guide plate from rattling.

In order to solve at least one of the above problems, the present invention has the following configuration. That is,
A support plate;
A light guide plate disposed on the front side of the support plate, the light guide plate emitting light from the light source introduced from the end surface from the front, and an optical sheet disposed on the front side of the light guide plate In the backlight device
A holding member attached to the upper end of the support plate, the holding member provided with a holding portion on the lower surface side;
The light guide plate includes a rib projecting on the back side at the upper end, and a step at the edge of the upper end surface,
The support plate includes a receiving seat at a position corresponding to the rib,
When the holding member is mounted, the light guide plate is held by the support plate by the ribs being held in the vertical direction by the holding portion and the receiving seat. 1 configuration).

According to the said 1st structure, a light-guide plate is hold | maintained at a support plate using the rib with which the upper end part of the light-guide plate was equipped. In this way, only one end side (upper end side) of the light guide plate is used for holding and fixing by the support plate, and the other end (lower end) is made free, so that it is possible to follow the expansion of the light guide plate due to temperature change, Interference with surrounding members is avoided. On the other hand, as a result of the step provided at the edge of the upper end surface of the light guide plate functioning as a barrier against dust and the like, entry of dust and the like into the central region (light incident region) of the upper end surface is prevented. As a result, quality deterioration such as generation of turbulent light and a decrease in luminance can be prevented. By providing a step on the upper end surface in this way, the structure is strong against dust.
Moreover, in the said structure, since it positions between a receiving seat, a holding part, and a rib, a light-guide plate can be hold | maintained to a support plate by desired arrangement | positioning. That is, high positioning accuracy can be obtained. Furthermore, by adopting a holding means that is sandwiched between the receiving seat and the holding portion, the light guide plate can be securely held on the support plate with a high holding force, and the structure is strong against vibration. Therefore, it is possible to prevent the light guide plate from rattling and the accompanying abnormal noise when used in an environment with a lot of vibration such as in a vehicle.

  In the 2nd structure of this invention, a level | step difference is provided in the both edges of the upper end surface of a light-guide plate, respectively. As a result, the intrusion of dust from both edges can be prevented, and the structure is further resistant to dust.

  In the third configuration of the present invention, in the first or second configuration, the holding member has a portion formed in a shape corresponding to the step, and when the holding member is attached, the portion hits the step. Touch. Thus, by having comprised so that a part of holding member may closely_contact | adhere with respect to a level | step difference, the penetration | invasion of dust can be blocked | prevented more reliably.

  According to a fourth configuration of the present invention, in the first to third configurations, the holding portion of the holding member has a box shape with an opening at the front and the bottom, and the rib of the light guide plate is provided in the holding portion when the holding member is mounted. By being accommodated, the rib is surrounded by the holding portion and the receiving seat of the support plate, and at the same time, is sandwiched in the vertical direction. According to this configuration, as a result of the ribs provided at the upper end portion of the light guide plate being surrounded by the receiving seat of the support plate and the holding portion of the holding member, the gaps between the members are reduced. That is, the rib is held in a state close to hermetic sealing, and it is possible to prevent intrusion of dust or the like through the periphery of the rib.

  In the fifth configuration of the present invention, in the first to fourth configurations, the holding portion of the holding member includes a wall surface that contacts the side surface of the rib of the light guide plate. According to this configuration, when the rib of the light guide plate is sandwiched in the vertical direction by the support seat of the support plate and the holding part of the holding member, only a part of the holding part comes into contact with the side surface of the rib, thereby In addition, the light guide plate is positioned also in the left-right direction. In addition, it is possible to prevent displacement of the assembled light guide plate in the left-right direction. As described above, this configuration is effective in preventing the positional deviation of the light guide plate.

  In the sixth configuration of the present invention, in the first to fourth configurations, two ribs are provided so as to be arranged along the upper end surface of the light guide plate, and each holding provided in the holding member corresponding to this is provided. The portion has a first wall surface that contacts the upper surface of the rib and a second wall surface that contacts the outer surface. According to this configuration, the upper end portion of the light guide plate is provided with two left and right ribs, and when the rib of the light guide plate is vertically clamped by the support seat of the support plate and the holding portion of the holding member (each The upper surface of the rib contacts the first wall surface of the corresponding holding portion), and the outer surface of each rib (the left side surface for the left rib and the right side surface for the right rib) contacts the second wall surface of the holding portion. As a result, the light guide plate is held on the support plate in a state of being accurately positioned not only in the vertical direction but also in the horizontal direction. It is also possible to prevent the light guide plate from moving in the left-right direction after assembly. As described above, this configuration is extremely effective in improving positioning accuracy and preventing misalignment. Furthermore, by using two ribs, the holding force can be significantly increased without complicating the configuration.

  In the seventh configuration of the present invention, in the sixth configuration, one of the two ribs is provided at the left edge of the upper end portion of the light guide plate, and the other is provided at the right edge of the upper end portion of the light guide plate. In this configuration, a high holding force can be obtained by maximally separating the two ribs serving as the holding portions of the light guide plate with respect to the support plate. In addition, since the holding parts are formed at the left and right edges of the upper end of the light guide plate, it is effective that the left and right edges of the light guide plate are displaced in the front-rear direction due to external vibration, expansion and contraction of the light guide plate, etc. Can be prevented. Furthermore, since it becomes easy to confirm the rib which is a holding | maintenance part when hold | maintaining a light-guide plate to a support plate, the improvement of assembly workability | operativity is also aimed at.

  According to an eighth configuration of the present invention, in the first to seventh configurations, the holding member includes a wall surface that comes into contact with an upper end region in front of the light guide plate. In this configuration, the upper end region in front of the light guide plate is held between the holding member and the support plate. Accordingly, the light guide plate can be positioned in the front-rear direction, and the light guide can be prevented from being displaced in the front-rear direction. In addition, the light guide plate is more reliably held by the support plate.

  The present invention further includes, as a ninth configuration, in the first to eighth configurations, a first small protrusion formed on the left edge of the front upper end, and a second small protrusion formed on the right edge of the front upper end. And a light guide plate provided with a third small protrusion formed at the reference position of the front lower end, and a first hole formed in a position corresponding to the first small protrusion through which the first small protrusion is inserted. A second hole formed at a position corresponding to the second small protrusion, and a position corresponding to the third small protrusion. The backlight is characterized in that the first hole and the second hole are long holes that are long in the left-right direction, and the third hole is a long hole that is long in the vertical direction. Providing equipment.

According to the ninth configuration, the optical sheet is held by the light guide plate by inserting the small protrusion provided on the front surface of the light guide plate into the first to third holes formed in the optical sheet. The Since the light guide plate and the optical sheet are affected by the expansion and contraction in the left and right direction and are on the fixed end side, the first hole and the second hole at positions where the influence of the expansion and contraction in the vertical direction can be ignored are long in the left and right direction. By making the holes, it is possible to follow a change in position in the left-right direction when the light guide plate and the optical sheet are expanded and contracted while preventing vertical displacement. In addition, by making the third hole at a position where the influence of expansion / contraction is negligible greatly affected by the influence of expansion / contraction in the vertical direction, and being in the reference position with respect to the left / right direction, It is possible to follow a change in position in the vertical direction when the light guide plate and the optical sheet are expanded and contracted while preventing a positional shift in the horizontal direction. As a result, when the positional relationship between the light guide plate and the optical sheet changes due to expansion / contraction of the light guide plate and the optical sheet, the small protrusion moves in the left and right directions in the first hole and the second hole, and the third hole The small protrusion moves up and down. As a result of such movement of the small protrusions, no stress is applied to the optical sheet, and the occurrence of bending and warping of the optical sheet can be prevented. This avoids interference between the optical sheet and surrounding members (particularly the light guide plate).
The “reference position” that is the formation position of the third small protrusion can be arbitrarily set, but the center in the left-right direction is preferably set as the reference position here. This is because the support or holding action of the optical sheet by the third small protrusion and the third hole is maximized. In addition, the optical sheet has left-right symmetry, which facilitates the design of each hole.

  In the tenth configuration of the present invention, the clearance when the corresponding small protrusion is inserted is 0 mm to 0.45 mm above and below the first hole and the second hole, and the left and right of the first hole and the second hole are Each is 0.8 mm to 1.03 mm, the top of the third hole is 0.85 mm to 1.08 mm, and the left and right of the third hole are 0 mm to 0.45 mm, respectively. By setting the clearance in this way, the above-described action (preventing displacement and following position change) by each small protrusion and each hole is exhibited well.

  In the eleventh configuration of the present invention, in the ninth or tenth configuration, the fourth small protrusion formed on the left edge of the front lower end and the fifth small protrusion formed on the right edge of the front lower end are guided. The optical plate further includes a hole through which the fourth small protrusion is inserted and formed at a position corresponding to the fourth small protrusion, and a hole through which the fifth small protrusion is inserted and corresponds to the fifth small protrusion. The optical sheet further includes a fifth hole formed at the position to be. According to this configuration, the lower left edge of the optical sheet is supported by inserting the fourth small protrusion into the fourth hole, and the lower right edge of the optical sheet is similarly inserted by inserting the fifth small protrusion into the fifth hole. Is supported. This ensures that when the optical sheet is placed on the light guide plate, the left and right edges of the lower end of the optical sheet are arranged at desired positions. In addition, it is possible to prevent the lower left and right edges of the optical sheet from interfering with surrounding members when the light guide plate and the optical sheet are expanded and contracted.

In the twelfth configuration of the present invention, in the eleventh configuration, the clearance of the fourth hole and the fifth hole when the corresponding small protrusion is inserted is equal to or more than the upper and lower clearances in the third hole in the vertical direction. The left and right sides are equal to or longer than the left and right clearances in the first hole, respectively. By setting the clearance in this way, the fourth hole and the fifth hole follow the position change in the horizontal direction and the vertical direction accompanying the expansion and contraction of the light guide plate and the optical sheet, and the deflection and warpage of the optical sheet are caused. Can be prevented.
For example, the clearances of the fourth hole and the fifth hole are 0.8 mm to 1.25 mm in the top and bottom, respectively, and 1.3 mm to 1.85 mm in the left and right respectively (the thirteenth configuration of the present invention). By setting the clearance in this way, the above-described action by each small protrusion and each hole is exhibited well.

In the fourteenth configuration of the present invention, in the ninth to thirteenth configurations, the light guide plate further includes a sixth small protrusion formed at the reference position of the front upper end, and the sixth small protrusion is inserted through the hole. The optical sheet further includes a sixth hole formed at a position corresponding to the sixth small protrusion. According to the said structure, the upper end part of an optical sheet will be supported thru | or hold | maintained at three places (the position of a 1st hole, the position of a 2nd hole, and the position of a 6th hole). Therefore, it is more effective in preventing the positional deviation of the optical sheet or the occurrence of bending or warping.
The “reference position” that is the formation position of the sixth small protrusion can be arbitrarily set, but the center in the left-right direction is preferably set as the reference position here. This is because the support or holding action of the optical sheet by the sixth small protrusion and the sixth hole is maximized. In addition, the optical sheet has left-right symmetry, which facilitates the design of each hole.
For example, the clearance of the sixth hole is 0.3 mm to 0.75 mm on the top and bottom, respectively, and 0.9 mm to 1.35 mm on the left and right, respectively (fifteenth configuration of the present invention). By setting the clearance in this way, the above-described action by the sixth small protrusion and the sixth hole is satisfactorily exhibited.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of a backlight device 1 according to an embodiment of the present invention. 2 to 7 are a front view, a rear view, a left side view, a right side view, a plan view, and a bottom view of the backlight device 1 in order. The backlight device 1 includes a shield case (support plate) 10, a reflective sheet 20, a light guide (light guide plate) 30, a diffusion sheet 40, a vertical prism sheet 50, a horizontal prism sheet 51, an upper holder (holding member) 60, a printed circuit board. The assembly includes an assembly 70, a left side holder 80, a right side holder 85, and a TFT holder 90. In the backlight device 1, as illustrated, the reflection sheet 20, the light guide 30, the diffusion sheet 40, the vertical prism sheet 50, and the horizontal prism sheet 51 are stacked in this order on the front side of the shield case 10. Further, the upper holder 60 and the printed board assembly 70 are attached to the upper end portion of the shield case 10.

First, the configuration of the shield case 10 will be described with reference to FIG. 1 and FIGS. 8 to 12 are a front view, a rear view, a left side view, a right side view, and a plan view of the shield case 10 in order. 13 is a cross-sectional view taken along line AA in FIG. 8, and FIG. 14 is a cross-sectional view taken along line BB.
The shield case 10 is a surface-treated steel plate (SECC) having a substantially rectangular shape (height: about 100 mm, width: about 300 mm) in plan view. The shield case 10 functions as a support member for the light guide 30 described later, and also functions as a shield against electromagnetic induction.
On the left and right edges of the upper end portion of the shield case 10, rib receiving seats 11 each having a surface bent toward the back side are provided. The upper end portion on the inner side of the rib receiving seat 11 is bent to the back side at a position one step higher than the rib receiving seat 11, and the upper holder seating surface 12 and the printed board assembly seating surface one step higher than this. 13 is formed. Each printed board assembly seating surface 13 is formed with screw holes 13a and projections 13b used for positioning and holding the printed board assembly 70. On the back side of the upper end portion of the shield case 10, tongue pieces 14 extending vertically downward are provided at four locations at predetermined intervals. The tongue piece 14 is used to hold the upper holder 60.

The left and right edges of the shield case 10 are bent in a U-shape, thereby forming the accommodating portion 15 of the left holder 80 and the accommodating portion 16 of the right holder 85. Of the opposing surfaces constituting the left holder accommodating portion 15, the inner surface 15a is provided with an upper holder fixing hole 15b at one location, and TFT holder fixing claws 15c are formed at four locations. ing. The lower end of the surface 15a is bent in an L shape toward the outside, and a screw hole 15d for fixing the TFT holder is formed in the bent portion. Similarly, the right holder accommodating portion 16 includes an upper holder fixing hole 16b, a TFT holder fixing locking claw 16c, and a TFT holder fixing screw hole 16d.
Reference numeral 17 denotes a hole formed for heat dissipation and weight reduction, reference numeral 18 denotes a screw hole for fixing the backlight device, and reference numeral 19 denotes a reinforcing rib.

  The reflection sheet 20 is a resin sheet made of white polyester having a rectangular shape in plan view, and reflects light leaking from the back surface of the light guide 30 in the front direction. This improves the light utilization rate. In addition, the luminance unevenness of the light emitted from the light guide 30 is reduced by the diffusing action of the reflection sheet 20. A similar effect can be obtained by performing a reflection process on the back surface of the light guide 30 instead of using the reflection sheet 20.

Next, the configuration of the light guide 30 will be described in detail with reference to FIG. 1 and FIGS. 15 to 17 are a front view, a left side view, and a top view of the light guide 30 in this order. Further, FIG. 18 shows an enlarged view of a portion A in FIG. 15, and FIGS. 19 and 20 show enlarged views of a portion A and a portion B in FIG.
The light guide 30 is a light guide plate having a substantially rectangular shape in plan view, and the material thereof is polymethyl methacrylate (PMMA). The light guide 30 may be manufactured using polyethylene terephthalate (PET), polycarbonate resin, epoxy resin, glass, or the like as a material.
In this light guide 30, a region excluding the left and right edges of the upper end surface is a light incident region 31, and a region excluding the edge portion of the front surface 32 is a light emitting region 32 a. The left and right edges of the upper end portion of the light guide 30 are provided with holding projections (holding ribs 34) that protrude to the back side. The shape of the holding rib 34 is a substantially quadrangular prism, and the height (the distance from the light guide back surface 33 to the front end surface 34a of the holding rib 34) is about 3 mm. The thickness of the light guide 30 is constant (about 3.0 mm) except for the portion where the holding rib 34 is provided.

  A region where the holding rib 34 is formed (that is, both the left and right edges of the upper end portion of the light guide 30) is formed in a shape in which a part is cut away. Thus, a pair of left and right upper end step surfaces 35 and a pair of left and right side end step surfaces 36 are formed. The upper end step surface 35 forms a height difference on the upper end surface of the light guide 30 (the region on the center side becomes a high position) and functions as a barrier against dust. That is, as can be seen from FIG. 21a showing the upper end portion of the light guide 30 and FIG. 21b showing the state after the backlight device 1 is assembled, intrusion of dust into the light incident area 31 side is blocked by the upper step surface 35. The As a result, quality deterioration such as generation of turbulent light and a decrease in luminance can be prevented. By providing the upper end step surface 35 in this manner, a structure that is strong against dust is obtained. In this embodiment, one step is provided, but a plurality of steps 35a may be provided as shown in FIG. 42a. In that case, each step 35b may be separated as shown in FIG. 42b. Furthermore, it is also possible to provide a protruding barrier 35c as shown in FIG. The side end step surface 36 is used as a receiving seat for the upper holder 60.

On the front surface 32 of the light guide 30, the left and right edges (first pin 37a and second pin 37b) and the center (sixth pin 37f) of the upper end, and the left and right edges (fourth pin 37d and the second pin) of the lower end. Pins (small protrusions) are provided at a total of six positions including the positions of the 5 pins 37e) and the center (third pin 37c). In this embodiment, the distance between the pins formed at the upper end (first pin 37a, second pin 37b and sixth pin 37f) and the upper end is about 4 mm, and the pin formed at the lower end (fourth pin 37d). The distance between the fifth pin 37e and the third pin 37c) and the lower end is about 3 mm. As will be described later, these pins cooperate with holes formed in the optical sheet (the diffusion sheet 40, the vertical prism sheet 50, and the horizontal prism sheet 51) to position and hold the optical sheet, Exhibits functions such as deflection prevention. These pins 37a-f are all cylindrical with a diameter of about 1.3 mm and a height of about 0.5 mm. The shape of the pins 37a to f is not limited to this example, but it can be easily inserted into a hole formed in the optical sheet to be described later, and an excessive load is applied to the optical sheet during and after insertion. A shape that does not add (such a load causes deformation of the hole) is good, and in addition to a cylindrical shape, an elliptical column shape or the like can be adopted.
The sizes of the pins 37a to 37f are not particularly limited. The diameter of the pins 37a to f is, for example, 0.5 mm to 3.0 mm, and the height is, for example, 0.3 mm to 1.0 mm.
Further, the positions where the pins 37a to 37f are formed can be arbitrarily set on condition that the above functions can be exhibited and the light emission characteristics of the backlight device 1 are not affected. However, it is preferable to form the first pin 37a and the second pin 37b in a symmetrical positional relationship as in this embodiment. The same applies to the fourth pin 37d and the fifth pin 37e.

The diffusion sheet 40 laminated on the front side of the light guide 30 is a polyethylene terephthalate (PET) sheet containing a diffusion material. The vertical prism sheet 50 is a sheet in which a polyester film layer (prism layer) is formed on the surface of a base material made of acrylic resin. The horizontal prism sheet 51 has the same configuration. In these three sheets, holes are formed at positions corresponding to the pins 37a to 37f in the same manner. Hereinafter, with reference to FIGS. 22 and 23, a specific configuration of each hole will be described using the diffusion sheet 40 as an example. 22 is a plan view of the diffusion sheet 40, and FIG. 23 is a plan view showing a state in which the diffusion sheet 40 is held by the light guide 30 and a partially enlarged view thereof.
As shown in FIG. 22, the diffusion sheet 40 has holes 41a to 41f formed at a total of six locations. These holes are classified into four types. First, the holes (first hole 41a and second hole 41b) formed on the left and right edges of the upper end portion are used for positioning and holding the diffusion sheet 40 with respect to the light guide 30, and for expansion and contraction of the light guide 30 and the diffusion sheet 40. It also has the three functions of following the change in position in the left-right direction (position adjustment in the left-right direction) and preventing vertical position shift. The first hole 41a and the second hole 41b are long holes that are long in the left-right direction so that these functions can be exhibited (see the A and B enlarged views of FIG. 23). The specific hole diameter is about 1.5 mm in the vertical direction and about 3.0 mm in the horizontal direction.
The hole (third hole 41c) at the center of the lower end portion is positioned and held with respect to the light guide 30 and follows the vertical position change accompanying the expansion and contraction of the light guide 30 and the diffusion sheet 40 (up and down). (Position adjustment in the direction) and prevention of misalignment in the left-right direction. In order to exhibit these functions, the third hole 41c is a long hole that is long in the vertical direction (see the C-part enlarged view of FIG. 23). The specific hole diameter is about 3.0 mm in the vertical direction and about 1.5 mm in the horizontal direction.
The holes (the fourth hole 41d and the fifth hole 41e) formed in the left and right edges of the lower end are used for supporting the diffusion sheet 40. That is, by providing the hole, when the diffusion sheet 40 is placed on the light guide, it is ensured that the left and right edges of the lower end of the diffusion sheet 40 are arranged at desired positions. In addition, it is possible to prevent the right and left edges of the diffusion sheet 40 from interfering with surrounding members when the light guide 30 and the diffusion sheet 40 are expanded and contracted. In addition, the hole has a perfect circle shape with a hole diameter of 3.0 mm so as to be able to follow a change in position in the left-right direction and the up-down direction accompanying expansion / contraction of the light guide 30 and the diffusion sheet 40.
A hole (sixth hole 41f) at the center position near the upper end serves as a reference for positioning in the vertical and horizontal directions, and has a perfect circle shape with a hole diameter of about 1.5 mm. The hole is also used for holding the center of the upper end portion of the diffusion sheet 40.

  As shown in FIG. 23, the diffusion sheet 40 is held by the light guide 30 in a positioned state by inserting the corresponding pins 37a-f into the holes 41a-f. It can be seen that the positions where the holes 41a to 41f are formed are set so that the corresponding pins are located approximately at the center thereof.

  The sizes of the holes 41a to 41f are set in consideration of the sizes of the pins 37a to 37f, the thermal expansion coefficients of the light guide 30 and the diffusion sheet 40, and the examples shown in this embodiment are only examples. Absent. If the example of the magnitude | size of each hole is shown, about the 1st hole 41a and the 2nd hole 41b, when a pin is penetrated, it will be 0 mm-0.45 mm at a time, for example, 0 mm-0.2 mm at a time, Preferably it will be left and right For example, the clearance is 0.4 mm to 1.03 mm, preferably 0.8 mm to 1.03 mm. Similarly, for the third hole 41c, when the pin is inserted, for example, 0.28 mm to 1.08 mm in the vertical direction, preferably 0.85 mm to 1.08 mm, and for example, 0 mm to 0.45 mm in the horizontal direction, preferably Is such a size that a clearance of 0 mm to 0.2 mm is secured. In addition, the fourth hole 41d and the fifth hole 41e are large enough to ensure a clearance of, for example, 0.8 mm to 1.25 mm vertically and 1.3 mm to 1.85 mm horizontally when the pin is inserted. Say it. The sixth hole 41f has such a size that a clearance of, for example, 0.3 mm to 0.75 mm in the vertical direction and 0.9 mm to 1.35 mm in the horizontal direction are secured when the pin is inserted.

  Although the number and formation position of each hole depend on the number and formation position of the pins formed in the light guide, those shown in FIGS. 22 and 23 are merely examples. For example, the first hole 41a (or the second hole 41b) has a function equivalent to that of the first hole 41a (or the second hole 41b). One or more holes between 41a and the sixth hole 41f and between the second hole 41b and the sixth hole 41f, or a hole that exhibits the same function as the fourth hole 41d (or the fifth hole 41e) (holding) One or more holes may be provided between the fourth hole 41d and the third hole 41c and between the fifth hole 41e and the third hole 41c.

  It should be noted that making the structure complicated is not preferable because it causes an increase in manufacturing cost and there is a concern about the influence on the light emission characteristics of the backlight device. The backlight device 1 of the present embodiment has a very simple configuration by providing one hole for adjusting the left / right position on each of the left and right edges and one hole for adjusting the vertical direction at the center position. Realized.

Next, the configuration of the upper holder 60 will be described in detail with reference to FIG. 1 and FIGS. 24 to 28 are a front view, a rear view, a left side view, a plan view, and a bottom view of the upper holder 60 in order. 29 is a sectional view taken along line AA in FIG. 24, FIG. 30 is an enlarged view of a portion B in FIG. 24, FIG. 31 is an enlarged view of a portion C in FIG. FIG. 33 is a sectional view taken along the line EE of FIG. FIG. 34 is a view of the left edge portion of the upper holder 60 observed obliquely from below.
The upper holder 60 is symmetrical and has a substantially linear shape, and its length is slightly shorter than the width of the light guide 30. The upper holder 60 is an integrally molded product made of white resin (polycarbonate).
A plurality of rectangular openings 61 are formed on the front end side of the upper holder 60 at regular intervals along the longitudinal direction. An LED lamp 72 described later is accommodated in each opening 61.
A holding portion 62 for the holding rib 34 of the light guide 30 is provided on the lower surface side of the left and right edges of the upper holder 60. The holding part 62 has a box shape with the front (front side of the backlight device 1) and the lower side (lower surface side of the backlight device 1) opened (FIGS. 30 to 32). Further, a step surface 68 formed in a shape corresponding to the upper end step surface 35 of the light guide 30 is provided at a position close to the outermost opening 61 (FIGS. 31 and 32). When the upper holder 60 is attached to the upper end portion of the shield case 10, the step surface 68 comes into contact with the upper end step surface 35 of the light guide 30.
On the other hand, on the lower surface side of the front end portion of the upper holder 60, a concave strip portion 63 and a convex strip portion 64 are formed over substantially the entire width of the upper holder 60 (FIGS. 31 and 33). As shown in the figure, the concave strip portion 63 is positioned forward.
A first narrow extension 65 is formed on the left and right edges of the rear end side of the upper holder 60, and a second narrow extension 66 is formed at the center position. Also, a total of four wide extending portions 67 are formed in a symmetrical relationship so as to be sandwiched between the first narrow extending portion 65 and the second narrow extending portion 66.
A locking leg 65a is provided on the upper surface side of each first narrow extension 65, and a locking leg 65b is also provided on the lower surface side. In addition, two locking legs 66 a are provided on the upper surface side of each second narrow extension portion 66. On the other hand, each wide extending portion 67 is provided with a tongue-like locking leg 67a extending downward at a substantially central position. The wide extension 67 adjacent to the first narrow extension 65 is also provided with a positioning projection 67b on the upper surface side.

As shown in FIG. 35, the printed circuit board assembly 70 has a configuration in which an LED lamp 72 is mounted on a single-sided Al substrate 71. The printed board assembly 70 is connected to a control circuit and a power source via a connector (not shown). The backlight device 1 uses two printed circuit board assemblies 70 having the same configuration. In the region on the front end side of the substrate 71, the LED lamps 72 are mounted in a line along the longitudinal direction at equal intervals. On the other hand, the area on the rear end side is used for mounting and fixing the printed circuit board assembly 70, and there are positioning and fixing holes 71a and 71b for the shield case 10, and positioning and positioning holes 71c for the upper holder 60. And a notch 71d used for holding by the upper holder 60 is formed.
The LED lamp 72 is a surface mount type (SMD type) LED lamp that emits white light, and a blue light emitting LED chip is surrounded by a white resin reflector and sealed with a resin containing a yellow phosphor. Is provided. Reference numerals 72a and 72b denote an electrode lead and a heat dissipation lead, respectively. The heat of the LED lamp 72 is efficiently radiated to the substrate 71 via the heat radiation lead 72b.

  The left holder 80 and the right holder 85 are both integrally molded products made of ABS resin, and their height (length in the longitudinal direction) is substantially the same as the height of the shield case 10 (FIG. 1). The lower end portions 81 and 86 of each holder protrude in an L-shaped cross section. The protrusion has a screw hole and is used for fixing each holder to the shield case 10. A similar fixing screw hole is also formed in the center of each holder.

  The TFT holder 90 is a frame-like member (FIG. 1), on which a TFT panel is placed when a liquid crystal display device is constructed later. The TFT holder 90 is also used for holding an optical sheet. The left and right edges 91 and 92 of the TFT holder 90 are bent toward the back side and provided with holes 91a and 92a drilled at substantially equal intervals. The hole is used for fixing to the shield case 10.

  The backlight device 1 composed of the above members is assembled in the following order. First, the reflection sheet 20 is placed on the front side of the shield case 10. Next, the light guide 30 is similarly placed on the reflection sheet 20. At this time, the holding rib 34 of the light guide 30 is supported by the rib receiving seat 11 of the shield case 10 (FIG. 36). As a result, the light guide 30 is positioned with respect to the shield case 10.

Subsequently, the upper holder 60 is attached to the upper end of the shield case 10 (FIGS. 37 and 38). For mounting the upper holder 60, locking legs 65b and 67a provided on the upper holder 60 are used. That is, the upper holder 60 is placed on the upper end of the shield case 10 in a predetermined positional relationship, and the locking leg 65b is engaged with the locking holes 15b and 16b formed in the grooves 15 and 16 of the shield case 10 (see FIG. 37, FIG. 38), the locking leg 67a is locked to the tip of the tongue piece 14 of the shield case 10 (FIG. 4). At this time, the lower surfaces of the extending portions 65 to 67 of the upper holder 60 abut on the upper holder receiving seat 12 of the shield case 10. On the other hand, the holding rib 34 of the light guide 30 is accommodated in the holding portion 62 of the upper holder 60, and is sandwiched in the vertical direction by the ceiling portion 62 a of the holding portion 62 and the rib receiving seat 11 of the shield case 10. At the same time, the outer side surface 34a of the holding rib 34 comes into contact with the inner wall surface 62b of the holding portion 62 (FIGS. 34 and 36 to 38). As a result, the light guide 30 is held by the shield case 10 in a state of being accurately positioned in the left-right direction. Further, it is possible to prevent the light guide 30 from being displaced in the left-right direction during the subsequent assembly work or after the assembly work (when the liquid crystal panel is mounted or the backlight device is used).
Here, as described above, the holding portion 62 has a box shape with an opening at the front and the bottom, and when the upper holder 60 is attached to the shield case 10, the holding rib 34 is surrounded by the holding portion 62 and the rib receiving seat 11. (FIG. 38). That is, the holding rib 34 is held in a state close to hermetic sealing by the upper holder 60 and the shield case 10, and it is difficult for dust to enter from the periphery of the holding rib 34. As described above, the upper holder 60 forms a dust intrusion prevention structure in cooperation with the rib receiving seat 11 of the shield case 10, and prevents dust from entering the light incident area 31 and the light emitting area 32 a of the light guide 30. .

  On the other hand, when the upper holder 60 is mounted, the step surface 68 of the upper holder 60 comes into contact with the upper step surface 35 of the light guide 30. In this way, a part of the upper holder 60 is in close contact with a part of the upper end surface of the light guide 30 to prevent dust from entering the light incident area 31 side. As a result, it is possible to prevent quality degradation such as generation of turbulent light and reduction in luminance. When the upper holder 60 is mounted, the back surface 64a of the ridge 64 of the upper holder 60 comes into contact with the upper end region 32a on the front surface of the light guide 30 (FIG. 39A). As described above, as a result of the backward urging force of the convex portion 64 acting on the light guide 30, the light guide 30 is also held in the front-rear direction with respect to the shield case 10.

Next, the printed board assembly 70 is mounted on the upper holder 60 using the locking legs 65 a and 65 b of the upper holder 60 and the positioning protrusions 67 b of the wide extending portion 67. That is, the printed circuit board assembly 70 is placed on the upper surface side of the upper holder 60 in a predetermined positional relationship with the LED lamp mounting surface side down. Then, the locking legs 65a and 65b of the upper holder 60 are locked to the notch 71d portion of the printed circuit board assembly 70, and the positioning protrusion 67b of the wide extension portion 67 of the upper holder 60 corresponds to the printed circuit board assembly 70 side. The hole 71c is inserted. At this time, the positioning protrusions 13b formed on the printed board assembly receiving seat 13 of the shield case 10 are inserted into the corresponding holes 71b on the printed board assembly 70 side, and the LED lamp mounting surface side of the printed board assembly 70 is on the printed board assembly receiving side. It contacts the seat 13. As a result, the printed circuit board assembly 70 is temporarily fixed to the shield case 10 in a predetermined positional relationship. Thereafter, the screw hole 71a is used for screwing. In this way, the printed circuit board assembly 70 is fixed to the shield case 10.
As described above, positioning, holding, and fixing are performed between the shield case 10, the upper holder 60, and the printed circuit board assembly 70. As a result, positioning accuracy is improved and positional deviation after assembly can be prevented.

  As shown in FIG. 39A, when the printed circuit board assembly 70 is attached, the LED lamp 72 is accommodated in each opening 61 of the upper holder 60. The height of the opening 61 and the height of the LED lamp 72 are substantially equal, and the light emission surface of the LED lamp 72 and the upper end surface (light incident region 31) of the light guide 30 are close to each other. Thereby, the light of the LED lamp 72 can be efficiently incident on the light guide 30.

  After mounting the upper holder 60 and the printed circuit board assembly 70 as described above, the diffusion sheet 40, the vertical prism sheet 50, and the horizontal prism sheet 51 are placed on the front surface 32 of the light guide 30 in this order. At this time, the holes 41a to 41f provided in each optical sheet are inserted into the corresponding pins 37a to 37f of the light guide 30 (see FIGS. 22 and 23). At this time, the sixth pin 37f and the sixth hole 41f define the vertical and horizontal references, and the vertical positioning is performed between the first pin 37a and the first hole 41a and between the second pin 37b and the second hole 41b. In addition, positioning in the left-right direction is performed between the third pin 37c and the third hole 41c. On the other hand, by inserting a pin into each hole, each optical sheet is supported by the light guide 30 at a total of six locations in the center of the upper end and the center of the lower end in addition to the four corners, so that the deflection and warpage of the optical sheet can be reduced. Can be prevented. In this way, each optical sheet can be held by the light guide 30 in a well-positioned state and without bending or warping.

Subsequently, after the upper end 93 of the TFT holder 90 is inserted into the recess 63 of the upper holder 60 in a state of being slightly inclined with respect to the optical sheet surface (see FIG. 39B), the upper end 93 is used as a fulcrum. The holes 91 a and 92 a provided on both edges of the TFT holder 90 are pressed against the corresponding locking claws 15 c and 16 c of the holder housing portions 15 and 16 of the shield case 10 by being pressed against the optical sheet while being rotated. Lock.
Finally, the left holder 80 and the right holder 85 are fitted into the corresponding holder accommodating portions 15 and screwed.

  The light emission mode of the backlight device 1 assembled as described above is as follows. First, white light emitted from the LED lamp 72 is applied to the light incident region 31 of the light guide 30. The light introduced into the light guide 30 is guided through the light guide 30, and most of the light is finally emitted from the light emission region 32 a of the front surface 32 of the light guide 30. In the light guide 30, the light traveling in the front direction is efficiently generated and light is guided and diffused satisfactorily by the reflection and diffusion action of the back surface and the reflection sheet 20. As a result, light with high luminance and little luminance unevenness is emitted from the light emission region 32 a of the light guide 30. The light emitted from the light emitting region 32 a of the light guide 30 is further uniformized in brightness by the diffusion sheet 40, and then the directionality is adjusted by passing through the prism sheets 50 and 51. In this way, finally, planar light having a uniform luminous flux is emitted from the opening of the TFT holder 90.

In the backlight device 1 of the present embodiment, the holding rib 34 formed on the upper end portion of the light guide 30 is sandwiched in the vertical direction by the shield case 10 and the upper holder 60, so that the upper end of the light guide 30 is kept at the shield case 10. The lower end of the light guide 30 is free (free end). As a result, a configuration capable of following a temperature change during use of the backlight device 1 is realized. That is, since a sufficient clearance is secured between the light guide 30 and the shield case 10 except for the upper end side of the light guide 30, even if the light guide 30 expands with a temperature change, it interferes with peripheral members. There is nothing. As described above, the backlight device 1 can avoid interference between the shield case 10 and the light guide 30 even though the difference in expansion coefficient between the shield case 10 and the light guide 30 is large by using the specific holding means.
On the other hand, by adopting the holding means as described above, the light guide 30 can be accurately positioned with respect to the shield case 10. At the same time, the light guide 30 can be securely held in the shield case 10 with a high holding force, and the structure is strong against vibration. Accordingly, it is possible to prevent the light guide 30 from rattling and the accompanying noise generation when used in an environment with a lot of vibration such as in a vehicle. In particular, the holding ribs 34 are provided on the left and right edges of the light guide 30, that is, the holding portions are separated as much as possible, so that a high holding force can be obtained and vibration from the outside and expansion and contraction of the light guide 30 can be obtained. For example, it is possible to effectively prevent the right and left edge portions of the light guide 30 from being displaced in the front-rear direction. In addition, the holding ribs 34 can be easily confirmed, and the assembly workability can be improved.
On the other hand, when the outer surface 34a of the holding rib 34 abuts against the inner wall surface 62b of the holding portion 62 of the upper case 60, the light guide 30 is positioned in the left-right direction. This improves the position accuracy in the left-right direction and prevents the light guide 30 from being displaced in the left-right direction.

In the backlight device 1, as described below, when the light guide 30 and the optical sheet (the diffusion sheet 40, the vertical prism sheet 50, and the horizontal prism sheet 51) are expanded and contracted, stress is applied to the optical sheet. Ingenuity that is not added is applied to prevent deformation and deflection of the optical sheet due to expansion and contraction of the light guide 30 and the optical sheet.
First, the first hole 41a at a position where the influence of the expansion / contraction in the vertical direction is negligible due to the influence of the expansion / contraction in the left / right direction (that is, the position change in the left / right direction is remarkable) and the fixed end side. By making the second hole 41b (see FIGS. 22 and 23) a long hole in the left-right direction and having a minimum vertical clearance, it is possible to follow a change in position in the left-right direction while preventing vertical displacement. I am doing so. Similarly, it is greatly affected by expansion / contraction in the vertical direction (that is, the position change in the vertical direction becomes significant) and is in the reference position (center) in the left / right direction, so that the influence of the expansion / contraction can be ignored. By making the three holes 41c long in the vertical direction and having a minimum clearance on the left and right sides, it is possible to follow the positional change in the vertical direction while preventing the positional deviation in the horizontal direction. Further, the positions of the fourth hole 41d and the fifth hole 41e at positions where the position change is remarkable in both the left-right direction and the up-down direction are increased in diameter to ensure sufficient clearance, so that the position in the up-down-left-right direction can be increased. It is designed to follow changes. Further, with respect to the sixth hole 41f, the vertical and horizontal clearances are minimized to prevent positional displacement.
By designing the holes 41a to 41f as described above, when the positional relationship between the light guide 30 and the optical sheet changes due to the expansion / contraction of the light guide 30 and / or the optical sheet, the first holes on the left and right edges of the upper end portion. The pins 37a and 37b move in the left-right direction in the 41a and the second hole 41b (see FIG. 23), and the pin 37c moves in the vertical direction in the third hole 41c in the center of the lower end. In addition, the pins 37d and 37e move in the vertical direction and the horizontal direction in the fourth hole 41d and the fifth hole 41e at the left and right edges of the lower end. As a result of such pin movement, no stress is applied to the optical sheet. On the other hand, the first hole 41a and the second hole 41b have a vertical clearance that is set to a minimum, and no substantial positional deviation occurs in the vertical direction. For the same reason, there is no substantial displacement in the left-right direction in the third hole 41c. Further, in the sixth hole 41f, no substantial positional deviation occurs in the vertical and horizontal directions. As described above, the vertical position is maintained by the first hole 41a, the second hole 41b, and the sixth hole 41f, and the horizontal position is maintained by the third hole 41c and the sixth hole 41f. Is prevented from being displaced.
As described above, by designing each hole by skillfully calculating the influence of expansion / contraction at each position, a configuration that can follow the change in position due to expansion / contraction while preventing position shift is realized. .

  Further, in the backlight device 1, the holding portion 62 of the upper holder 60 and the rib receiving seat 11 of the shield case 10 surround the holding rib 34 of the light guide 30, and dust enters from the vicinity of the upper end portion of the light guide 30. Stop. As a result of such a structure that effectively prevents dust from entering, it is possible to prevent quality degradation such as generation of turbulent light and a decrease in luminance.

The above embodiment (backlight device 1) is only one example of the present invention. Accordingly, various modifications (changes) are possible without departing from the essence of the present invention. Specific examples of deformation are shown in FIGS.
FIG. 40A is a plan view showing a modification example regarding the light guide and the optical sheet. 40B is an enlarged view of a portion A in FIG. 40A, and FIG. 40C is a cross-sectional view taken along the line BB in FIG. 40A. In the light guide 100 of FIG. 40, a plurality of small rib-like protrusions 101 are provided at equal intervals along both the left and right edges on the front side. Corresponding to this, notches 106 are formed in the optical sheets (103 to 105). According to this configuration, the TFT holder 90 is supported by the rib-shaped small protrusions 101, and the left and right edges of the optical sheet can be prevented from being damaged due to interference with the TFT holder 90. In this example, the number of pins formed at the upper end and the lower end of the light guide is also added (two pins are added at the upper end and the lower end, respectively), whereby the TFT holder 90 is also provided at both the upper and lower edges of the optical sheet. And reduce interference.

  FIG. 41A is a modification of the upper holder mounting structure (FIG. 41B is a mounting structure of the backlight device 1). In this example, in the shield case 110, when the upper holder 60 is mounted, the portion 111 where the claw of the locking leg 65b comes into contact is curved to prevent the claw from being scratched, which may cause dust generation or decrease in holding power. ing. With the above-described deformation, the size of the claw of the locking leg 65b is increased in order to ensure reliable locking.

  The backlight device of the present invention can be used as a backlight for a mobile phone, a portable information terminal, a car navigation system, a laptop (notebook) PC, a liquid crystal television, and the like.

  The present invention is not limited to the description of the embodiments and examples of the invention described above. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.

1 is an exploded perspective view of a backlight device 1 according to an embodiment of the present invention. The front view of the backlight apparatus 1. FIG. The rear view of the backlight apparatus 1. FIG. The left view of the backlight apparatus 1. FIG. The right view of the backlight apparatus 1. FIG. FIG. 2 is a plan view of the backlight device 1. The bottom view of the backlight apparatus 1. FIG. The front view of the shield case 10. FIG. The rear view of the shield case 10. FIG. The left view of the shield case 10. FIG. The right view of the shield case 10. FIG. The top view of the shield case 10. FIG. Sectional drawing of the AA line position in FIG. Sectional drawing of the BB line position in FIG. The front view of the light guide 30. FIG. Left side view of light guide 30 The top view of the light guide 30. FIG. The enlarged view of A part of FIG. The enlarged view of A part of FIG. The enlarged view of the B section of FIG. The perspective view (a) which shows the upper end part of the light guide 30, and sectional drawing (b) which shows the state after the assembly of the backlight apparatus 1. FIG. The top view of the diffusion sheet 40. FIG. The top view which shows the state with which the diffusion sheet 40 was hold | maintained at the light guide 30, and its partial enlarged view. The front view of the upper holder 60. FIG. The rear view of the upper holder 60. FIG. The left view of the upper holder 60. FIG. The top view of the upper holder 60. FIG. The bottom view of the upper holder 60. FIG. Sectional drawing of the AA line position of FIG. The B partial enlarged view of FIG. The C partial enlarged view of FIG. Sectional drawing of the DD line position of FIG. Sectional drawing of the EE line position of FIG. The perspective view which observed the left edge part of the upper holder 60 from diagonally downward. The top view of the printed circuit board assembly 70. FIG. The perspective view which shows the state which mounted the light guide 30 in the shield case 10. FIG. The perspective view which shows the state which mounted | wore the light guide 30 with the upper holder 60. FIG. The perspective view which shows the state which mounted | wore the light guide 30 with the upper holder 60. FIG. Sectional drawing (a) which shows the state which mounted | wore the upper guide 60 and the printed circuit board assembly 70 to the light guide 30, and sectional drawing (b) which shows the state which mounted | wore the TFT holder 90. The modification of a light guide and an optical sheet. The top view (a) of the state which made the optical guide hold | maintain the light guide 100, the enlarged view (b) of A part, and sectional drawing (c) of the BB line position. The modification (a) of the attachment structure of an upper holder, and the attachment structure (b) of the backlight apparatus 1. FIG. The example of the upper end level | step difference surface formed in the light guide 30. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Backlight apparatus 10, 110 Shield case 11 Rib receiving seat 12 Upper holder receiving seat 13 Printed circuit board assembly receiving seat 14 Tongue piece 15 Left holder accommodating part 15b Upper holder fixing hole 15c Locking claw 16 Right holder accommodating part 16b Upper holder Fixing hole 16c Locking claw 20 Diffusion sheet 30, 100 Light guide 31 Light incident area 32 Light guide front face 32a Light emission area 33 Light guide rear face 34 Holding rib 34a Holding rib outer face 35, 36 Step surface 37a ~ F Pin 40 Diffusion sheet 41a ~ f Hole 50 Longitudinal prism sheet 51 Horizontal eye prism sheet 60 Upper holder 61 Opening part 62 Holding part 62a Ceiling part 62b of holding part Inner wall surface 65 of holding part First narrow width extending part 65a, 66a, 67a Locking leg 66 Second narrow extension part 67 Wide extension part 67b Positioning Use protrusion 68 stepped surface 70 PCB upper holder assembly 71 substrate 72 LED lamp 80 left holder 85 right holder 90 TFT holder 101 rib-shaped small projections

Claims (8)

A support plate;
A light guide plate disposed on the front side of the support plate, the light guide plate emitting light from the light source introduced from the end surface from the front, and an optical sheet disposed on the front side of the light guide plate In the backlight device
A holding member attached to the upper end of the support plate, the holding member provided with a holding portion on the lower surface side;
The light guide plate includes a rib projecting on the back side at the upper end, and a step at the edge of the upper end surface,
The support plate includes a receiving seat at a position corresponding to the rib,
When the holding member is mounted, the light guide plate is held by the support plate by the rib being held vertically by the holding portion and the receiving seat.   The backlight device according to claim 1, wherein the steps are provided at both edge portions of the upper end surface of the light guide plate.   The backlight device according to claim 1, wherein the holding member includes a portion formed in a shape corresponding to the step, and the portion contacts the step when the holding member is attached.   The holding part has a box shape with an opening at the front and the bottom. When the holding member is mounted, the rib is housed in the holding part, so that the rib is surrounded by the holding part and the receiving seat. The backlight device according to any one of claims 1 to 3, wherein the backlight device is sandwiched in the vertical direction at the same time.   The backlight apparatus in any one of Claims 1-4 with which the said holding | maintenance part is provided with the wall surface contact | abutted to the side surface of the said rib. Two ribs are provided so as to be aligned along the upper end surface of the light guide plate,
Correspondingly, each holding portion provided in the holding member has a first wall surface that contacts the upper surface of the rib and a second wall surface that contacts the outer surface. Backlight device.   The backlight device according to claim 6, wherein one of the two ribs is provided on a left edge of the upper end portion of the light guide plate, and the other is provided on a right edge of the upper end portion of the light guide plate.   The backlight apparatus in any one of Claims 1-7 with which the said holding member is provided with the wall surface contact | abutted to the upper end area | region of the front of the said light-guide plate.

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