JP5396929B2 - Backlight device and liquid crystal display device - Google Patents

Description

  The present invention relates to a backlight device and a liquid crystal display device in which the backlight device is used.

  As an image or video display device, a liquid crystal display (LCD) is generally widely used. In recent years, there has been an increasing demand for LCDs with a large display panel and a thin main body.

  Since the liquid crystal itself constituting the LCD does not emit light, an image is displayed using light from a light emitting device (backlight device) disposed behind.

  As a light source used in the backlight device, a point light source such as an LED (Light Emission Diode) or a linear light source such as a cold cathode fluorescent lamp (CCFL) is generally used.

  The backlight device takes a configuration called an edge light type or a direct type according to the arrangement position of the light source.

  The direct type backlight device is a plurality of light sources arranged at a predetermined interval directly below the liquid crystal display panel, and the light emitted from the light sources is transmitted through a diffusion plate provided on the back side of the liquid crystal panel so that the apparent top surface Light is emitted. In this case, the intensity of light is high near the light source, and the intensity of light decreases as the distance from the light source increases. There is a problem of appearing on a liquid crystal display screen.

  In particular, if the distance between the light source and the diffusion plate is shortened in order to cope with the reduction in the thickness of the backlight device, the lamp image appears remarkably, which causes the image quality of the LCD to deteriorate.

  As one means for eliminating these lamp images, for example, as shown in Patent Document 1, a method using a so-called lighting curtain is known.

  However, if the light shielding pattern shape of the lighting curtain is not optimal with respect to the position of the light source, the lamp image can be sufficiently erased even if an optical sheet such as a diffusion sheet (diffusion plate) or prism sheet is used. As a result, luminance unevenness appears on the image display surface of the liquid crystal display device.

  Also, as a result of the difference in distance from the light source caused by bending of the lighting curtain and the temperature rise due to heat generation of the light source, a difference in distance from the light source due to expansion and contraction of the lighting curtain occurs, which causes uneven brightness. Yes.

  For example, as disclosed in Patent Document 2, there is a certain distance between the lighting curtain or the diffusion plate and the light source, but the bending to the back frame side is suppressed. There is only an effect, and there is no effect of suppressing the deflection to the liquid crystal side (cell side).

  A method has also been proposed in which the tip of the spacer and the lighting curtain or diffusion plate are fixed with an adhesive or double-sided tape, but in order to fix it, the tip of the spacer is used as an adhesive surface, and the tip of the spacer is used to obtain adhesive strength. The area needs to be a certain size. When the area of the adhesion surface at the tip of the spacer is increased, the visibility of the liquid crystal display device on the image display surface is adversely affected. That is, the brightness of the adhesion part at the spacer tip becomes darker than the periphery of the spacer (parts other than the adhesion part at the spacer tip).

  In addition, in the method of fixing the spacer tip and the lighting curtain or diffusion plate with an adhesive, in addition to the visibility in the steady state, the height direction and the in-plane direction of the diffusion plate etc. Because of the support structure that restrains the displacement in the direction perpendicular to the thickness direction of the plate, when the diffusion plate expands and contracts due to the temperature rise due to the heat generated by the CCFL or the usage environment, the sheet is based on the tip of the spacer. (Lighting curtain or diffuser plate) is deformed (bent) in the thickness direction, and the distance between the lighting curtain or diffuser plate and CCFL changes at places other than the restraint part (adhesive part), and is visible on the image display surface of the liquid crystal display device. It will adversely affect sex.

  Further, for example, as shown in Patent Document 3, a difference in the distance between the light source and the lighting curtain or diffusion plate is suppressed by standing upright from the back frame and fixing the sheet or diffusion plate with an adhesive or double-sided tape. A scheme has also been proposed.

  However, once these columns and the lighting curtain (diffusion plate) are fixed once with adhesive or double-sided tape, etc., it is difficult to disassemble the backlight when replacing the lamp, etc. There is a problem that it is possible. In addition, if the column and the lighting curtain are completely restrained, as described above, there is no play of expansion and contraction of the lighting curtain due to temperature change and moisture absorption, and thermal distortion occurs mainly at the adhesion part with the column. There is a problem that brightness unevenness occurs.

  In addition, as a method not using a spacer, for example, as shown in Patent Document 4, a method has been proposed in which a rib is provided on the diffusion plate to increase the rigidity against the weight of the diffusion plate. For large and thin panels with a backlight thickness of about 10 mm, it is impossible to suppress the self-weight deflection with the thickness of these ribs, and increasing the thickness of the ribs to increase rigidity The presence of the ribs cannot be erased, resulting in luminance unevenness and deterioration of the display device.

Japanese Patent Publication No.59-8809 JP 2003-203503 A Japanese Patent Laid-Open No. 5-119313 JP 2003-215585 A

  By the way, in the conventional backlight device, when increasing the installation accuracy of the diffusion plate and suppressing the occurrence of luminance unevenness in the diffusion plate, the engagement portion between the support member supporting the diffusion plate and the diffusion plate, and the engagement portion There is a problem that brightness unevenness may occur in the periphery in the diffusion plate. This problem also occurs when a reinforcing member (rib) is installed on the diffusion plate in order to increase the rigidity of the diffusion plate in order to prevent the diffusion plate from bending.

  The present invention has been made in view of the above problems, and includes a support member that supports the diffusion plate, an engagement portion between the reinforcement member that reinforces the diffusion plate and the diffusion plate, and a diffusion plate around the engagement portion. An object of the present invention is to provide a backlight device capable of suppressing the occurrence of luminance unevenness and a liquid crystal display device using the backlight device.

According to a first aspect of the present invention, there is provided a housing whose one surface is an open surface, a light source disposed in the housing, the open surface of the housing, and a recess formed on the light source side surface. , possess a diffusion plate which transmits and diffuses light emitted from the light source, one end engages said recess and engaging said diffusion plate, a support member and the other end is engaged with the housing, wherein the diffuser the width of the cross-sectional shape in the recess of the plate is a backlight device that is narrower in the incident area of the light.

According to a second aspect of the present invention, there is provided a housing having one open surface, a light source disposed in the housing, the open surface of the housing, and a recess formed on the light source side surface. A diffusion plate that diffuses and transmits light emitted from the light source, and a support member that has one end engaged with the concave portion of the diffusion plate and the other end engaged with the housing. Is a line light source, and the support member extends in a direction intersecting the line light source and is provided on the light source side of the diffuser plate, and a protrusion amount from the diffuser plate is in the vicinity of the light source. small at the site, a back light equipment which is large at sites distant from the light source.

A third invention is a liquid crystal display device comprising the backlight device according to the first invention or the second invention.

  According to the present invention, it is possible to suppress the occurrence of luminance unevenness in the diffusion plate in the periphery of the engagement portion between the support member that supports the diffusion plate, the reinforcement member that reinforces the diffusion plate, and the diffusion plate, and in the periphery of this engagement portion. There is an effect that can be done.

It is sectional drawing which shows schematic structure of the liquid crystal display device 1 which concerns on embodiment of this invention. It is II arrow directional view in FIG. It is an enlarged view of the III section in FIG. It is a figure which shows the modification of the engagement state of the diffusion plate 32 and the supporting member 5, and is a figure corresponding to FIG. It is a figure which shows the modification of the engagement state of the supporting member 5, the bottomed case 31, and the reflection member 33, and is a figure corresponding to FIG. It is a figure which shows the aspect in which the supporting member 5 (5a) served as the lamp holder 35 for fixing CCFL34. It is a figure which shows the modification of the recessed part 65 of the diffusion plate 32, and the engaging part 67 of the supporting member 5. FIG. It is a figure which shows the modification of the recessed part 65 of the diffusion plate 32, and the engaging part 67 of the supporting member 5. FIG. It is a figure which shows the modification of the recessed part 65 of the diffusion plate 32, and the engaging part 67 of the supporting member 5. FIG. It is a figure which shows the modification of the recessed part 65 of the diffusion plate 32, and the engaging part 67 of the supporting member 5. FIG. FIG. 9 is a view in which an optical coupling agent 107 or the like is provided between the concave portion 65 of the diffusion plate 32 and the engaging portion 67 of the support member 5, and corresponds to FIG. It is a figure which shows the modification of the recessed part 65 of the diffusion plate 32, and the engaging part 67 of the supporting member 5. FIG. 6 is a perspective view showing a positional relationship between a dot shape 63 of the diffusion plate 32 and a CCFL 34. FIG. 3 is a front view of the liquid crystal display device 1 in which a reinforcing member 113 is provided on the diffusion plate 32. FIG. It is a figure which shows the XV-XV cross section in FIG. It is a figure which shows the XVI-XVI cross section in FIG. 5 is a perspective view of a reinforcing member 113. FIG. FIG. 16 is a cross-sectional view of the backlight device 3 provided with a lattice-shaped reinforcing member 113, corresponding to FIG. FIG. 6 is a perspective view of a lattice-shaped reinforcing member 113. FIG. 10 is a perspective view showing a modified example of a lattice-shaped reinforcing member 113. FIG. 10 is a front view showing a modification of the lattice-shaped reinforcing member 113. FIG. 16 is a cross-sectional view of the backlight device 3 provided with a lattice-shaped reinforcing member 113 according to a modification, and corresponds to FIG. 15. FIG. 6 is a diagram in which a marking 125 is provided on the diffusion plate 32. It is sectional drawing of the backlight apparatus 3 which provided the reinforcement member 113 which concerns on a modification, and is a figure corresponding to FIG.

  The liquid crystal display device 1 includes a liquid crystal panel 2 as a display unit in which the upper side in FIG. 1 is installed as a viewing side (display surface side; front side), and a direct backlight device 3 that illuminates the liquid crystal panel 2. ing. Note that the lower side of FIG. 1 is the rear side of the liquid crystal display device 1.

  The backlight device 3 includes an open bottomed case (a casing having one open surface) 31, and a diffusion plate (opening of the casing 31) covers the opening of the bottomed case 31. A light diffusing plate (32) for diffusing the light emitted from the CCFL 34 is disposed on the surface. The bottomed case 31 includes a reflective sheet (reflective member) 33 called a reflector, a CCFL (cold cathode tube) 34 serving as a light source, a lamp holder 35, and a plurality of support members (one end engages with a recess 65 of the diffusion plate 32. A support member (diffusing plate support member) 5 whose other end engages with the housing 31 is stored. Therefore, in the backlight device 3, the CCFL 34 is arranged on the back surface side (lower side in FIG. 1) of the diffusion plate 32, and the light emitted from the CCFL 34 passes through the diffusion plate 32, and the front surface (upper side in FIG. 1). Light is emitted from the surface and the emission surface.

  In addition, the backlight device 3 includes an optical sheet (for example, an optical sheet for improving a viewing angle such as a polarization separation film 41, a diffusion film 42, and a prism sheet 43). It is installed between the diffuser plate 32 of the backlight device 3. The optical sheet 4 is composed of, for example, three sheets, but is depicted as one sheet in FIG.

  In the liquid crystal display device 1 shown in FIG. 1, the gap between the diffuser plate 32 and the optical sheet 4 is spaced by a distance L1, and the distance between the optical sheet 4 and the liquid crystal panel 2 is spaced by a distance L2. The liquid crystal panel 2, the optical sheet 4, and the diffusion plate 32 are integrally installed on the edge of the rectangular opening of the bottomed case 31 by a rectangular annular chassis. At this time, the value of the interval L1 is almost “0”, and the value of the interval L2 is a very small value of “0” or more.

  The reflection member (reflector) 33 is disposed mainly on the rear side of the CCFL 34, and reflects light emitted from the CCFL 34 toward the front side (upper side in FIG. 1) of the liquid crystal display device 1. The diffusion plate 32 is formed in a flat plate shape, and is disposed in parallel to the CCFL 34 on the front side of the CCFL 34 at a predetermined distance from the CCFL 34. Further, the diffusion plate 32 is disposed at a position facing the bottom plate 61 of the reflection member 33 with respect to the CCFL 34.

  In addition, although the case where a plurality of linear light sources such as CCFLs 34 arranged in parallel with each other with a predetermined interval (arranged on the same plane) is used as the light source has been described, A point light source may be employed. A light source in the case of employing a point light source is configured by arranging a plurality of LEDs on a substantially same plane at a predetermined interval.

  Further, as a specific example, the diffusion plate 32 is made of a rectangular synthetic resin (milky white or other synthetic resin) having a thickness of about 2 mm, and the CCFL 34 is a cylinder having a tube diameter of about 3 mm and has a rectangular shape. A plurality of bottomed cases 31 (reflecting members 33) are arranged at a predetermined interval (23 mm; “p1 × 2” shown in FIG. 1) in the longitudinal direction. When the 42-inch size liquid crystal display device 1 is assumed, the number is 22. The distance between the diffusion plate 32 and the bottom plate 61 of the reflecting member 33 is 9 mm.

  More specifically, both sides of the diffusion plate 32 in the thickness direction are parallel to the CCFL 34, and the CCFL 34 and the diffusion plate 32 are installed apart from each other in the thickness direction of the diffusion plate 32.

  Further, a dot shape 63 for dimming light emitted from the CCFL 34 may be provided on the back surface (the lower surface in FIG. 1) of the diffusion plate 32 (see FIG. 13). For convenience of explanation, FIG. 13 shows a mode in which a dot shape 63 is provided on the front surface of the diffusion plate 32.

  The dot shape 63 provided on the diffusion plate 32 is, for example, the same as the dot shape described in Japanese Patent Application Laid-Open No. 2005-117023. By providing the dot shape 63, the light source is CCFL34 or the like. Regardless of the point light source such as a line light source or LED, the light source is dimmed, and the diffuser plate 32 can obtain uniform luminance. The dimming may be performed using a form other than the dot shape 63.

  The dot shape 63 is formed, for example, by printing white ink with high light reflectance on the diffusion plate 32, and the one near the position of the CCFL 34 has a large number of dots or a large dot diameter. As the distance from the CCFL 34 increases, the number of dots gradually decreases, or the dot diameter gradually decreases. The transmittance of the light emitted from the CCFL 34 through the diffusion plate 32 is optimally adjusted.

  The bottomed case 31 is formed in, for example, a metal rectangular bowl shape. The reflecting member 33 is formed in a rectangular bowl shape with, for example, resin. A reflection portion is formed on the inner surface of the reflection member 33. The reflecting member 33 is provided on the bottomed case 31 such that the outer surface thereof is in contact with the inner surface of the bottomed case 31 or opposed with a slight gap. The rectangular opening side of the bottomed case 31 and the reflecting member 33 is the front side of the backlight device 3 (the liquid crystal display device 1), and the bottomed case 61 and the reflecting member 33 are flat and rectangular bottom plates 61. This is the rear side of the backlight device 3.

  Each CCFL 34 is provided integrally with the bottomed case 31 and the reflecting member 33 near the bottom of the inner surface of the reflecting member 33 via the lamp holder 35. The longitudinal direction of the CCFL 34 coincides with the longitudinal direction (or the width direction) of the reflecting member 33 and the bottomed case 31. The CCFLs 34 are provided to extend in parallel with each other with a predetermined interval “p1 × 2”, and the distances between the CCFLs 34 and the planar bottom of the inner surface of the reflecting member 33 are equal. ing.

  Here, the support form of the diffusion plate 32 will be described. Since the diffusion plate 32 has a large area of the exit surface, the support member 5 supports the middle of the exit surface. And the diffusion plate 32 is prevented from bending.

  More specifically, a concave portion (a concave portion that does not penetrate to the front surface of the diffusion plate 32; a non-through hole or a groove-like concave portion that does not extend to the front surface of the diffusion plate 32) is formed on the back surface of the diffusion plate 32. 65 is provided. Then, the support member (separate from the diffuser plate 32 and the like, for example, a support member that is detachable from the diffuser plate 32) 5 is engaged with the recess 65 to support the diffuser plate 32.

  The diffusion plate 32 is installed in the bottomed case 31 by being supported by the support member 5. The support member 5 is formed in a columnar shape, for example, and one end in the height direction engages with the recess 65 to integrally support the diffusion plate 32, and the other end in the height direction has a bottomed case 31. And the reflection member 33 are integrally provided. Thereby, the diffusion plate 32 is provided integrally with the bottomed case 31.

  As will be described in detail later (see the engagement portion 67 of the support member 5 indicated by the broken lines in FIGS. 12A and 12C), the support member 5 has the thickness of the diffuser plate 32. It may be configured to be restrained in the vertical direction and to be supported with slight play in the in-plane direction of the diffusing plate 32 (direction orthogonal to the thickness direction of the diffusing plate 32). That is, the diffusion plate 32 is installed so that it cannot move with respect to the bottomed case 31 in this thickness direction, and the diffusion plate 32 with respect to the bottomed case 31 in this in-plane direction. It may be supported so that it can move with a little play.

  Although the support member 5 will be described in detail later, at least a part (for example, a portion on the diffusion plate 32 side) is made of a transparent material (light transmissive member; for example, a transparent resin) (related to the diffusion plate 32). The region other than the region and the region other than the region engaged with the housing 31 may be formed of a light transmissive member.), The recess 65 and the portion of the support member 5 engaged with the recess 65 The gap between the (engagement portion) 67 is filled with an optical coupling agent that is an optical property adjusting agent having the same optical properties as the diffusion plate 32 and the support member 5. In the case where the diffusing plate 32 is provided integrally with the support member 5, the optical coupling agent also has a function as an adhesive. Examples of the optical coupling agent include silicon grease and a light-transmitting adhesive.

  Here, the form of the recess 65 and the like provided in the diffusion plate 32 will be described.

  A plane perpendicular to the thickness direction of the diffusion plate 32 (a plane developed in the horizontal direction of FIGS. 1 and 3 and a direction perpendicular to the plane of FIG. 1; developed in a direction parallel to the plane of FIG. 2) The cross-sectional area of the recess 65 due to the flat surface) is larger at the portion on the front surface side of the diffusion plate 32 than at the portion near the back surface of the diffusion plate 32. Further, when viewed from the thickness direction of the diffusion plate 32, a cross section of the portion near the back surface (cross section of the recess 65) exists inside the cross section of the front surface portion (cross section of the recess 65).

  The engaging portion 67 of the support member 5 is formed in a shape that fits into the recessed portion 65 in the same shape as the recessed portion 65, and the engaging portion 67 engages with the recessed portion 65, whereby at least the diffusion plate 32. The diffusion plate 32 is constrained and supported by the support member 5 in the thickness direction.

  Specifically, the concave portion 65 of the diffuser plate 32 is, for example, a linear ant such that the width of the cross section by a plane perpendicular to the longitudinal direction is narrow in the incident region of the light emitted from the CCFL 34. The cross-sectional shape of the dovetail groove 65 formed by a flat surface orthogonal to the longitudinal direction of the dovetail groove 65 is a fixed shape (isosceles trapezoidal shape) (see FIGS. 1 and 3). Therefore, the width of the groove near the back surface of the diffusion plate 32 is smaller than the width of the groove on the front surface side of the diffusion plate 32. Furthermore, as described above, the cross-sectional area of the concave portion 65 formed by a plane orthogonal to the thickness direction of the diffusion plate 32 is small at a portion near the back surface of the diffusion plate 32, and In addition to being larger at the site, the cross section of the site near the back surface exists inside the cross section of the site on the front side.

  The diffusion plate 32 is formed by injection molding, and the recess 65 is formed at the time of injection molding. The recess 65 is formed by a dovetail groove, and the cross-sectional shape of the dovetail groove 65 by a plane orthogonal to the longitudinal direction of the dovetail groove is a constant shape. The structure of the mold that is not formed and used in the injection molding of the diffusion plate 32 is simplified.

  The engaging portion 67 of the support member 5 formed in a columnar shape is formed in a truncated cone shape. In the engaging portion 67, the upper surface of the truncated cone having a small area is located on the main body portion (for example, a main body portion formed in a columnar shape or a prismatic shape) 69, and the bottom surface having a large area is the supporting member 5. The main body 69 is located on the opposite side (one end of the support member 5). For example, the cross section of the main body portion 69 and the bottom surface of the engaging portion 67 formed by a plane perpendicular to the height direction of the support member 5 are in a form coincident with each other. Therefore, the constricted portion is formed on the one end side in the height direction of the support member 5 by the engaging portion 67.

  In a state where the engaging portion 67 of the support member 5 is engaged with the concave portion 65 of the diffusion plate 32 and the diffusion plate 32 is installed on the support member 5, for example, as shown in FIG. The bottom surface of the portion 67 (the bottom surface of the truncated cone; the front end surface of the support member 5) is in contact (more precisely, facing a very thin film of the optical coupling agent), and is engaged with the slope of the dovetail groove 65. The slope of the joint 67 (the slope of the truncated cone) is in contact (more precisely, it is opposed with a very thin film of the optical coupling agent in between). The diffusion plate 32 is restrained by the support member 5 at least in the thickness direction.

  In addition, in the state which engaged the engaging part 67 of the support member 5 with the recessed part 65 of the diffusion plate 32, and installed the diffusion plate 32 in the support member 5, as shown in FIG. 5 is in contact with the end surface of the main body 69 (the end surface on the engaging portion 67 side), the inclined surface of the dovetail groove 65 is in contact with the inclined surface of the engaging portion 67 (inclined surface of the truncated cone), and the diffusion plate 32 is at least The structure restrained by the support member 5 in this thickness direction may be sufficient.

  Further, the engaging portion 67 may be formed in a pyramid shape such as a quadrangular pyramid shape instead of a truncated cone shape. In this case, the main body 69 of the support member 5 may be formed in a columnar shape or a prismatic shape.

  Here, the aspect which installs the supporting member 5 in the bottomed case 31 is demonstrated in detail.

  The support member 5 is formed in a columnar shape as described above, and in this height direction, each part is in the order of the locking portion 71, the main body portion 69, and the engaging portion 67 from the proximal end side toward the distal end portion side. It has. The axes of the respective parts 71, 69, 67 coincide with each other.

  The locking part 71 is formed in an umbrella shape, and a notch 73 is formed in the central part of the locking part 71 along the axial direction (see FIG. 3). The locking portion 71 has elasticity in this radial direction.

  The support member 5 is provided integrally with the bottomed case 31 with the engaging portion 71 engaged with the bottomed case 31. That is, the support member 5 inserts the locking portion 71 into the through hole 75 provided in the bottom plate 77 of the bottomed case 31, so that the locking portion 71 fits into the through hole 75 and the tip of the locking portion 71. The bottomed case 31 is sandwiched between the part and the body part 69. The support member 5 stands up from the bottom of the inner surface of the bottomed case 31 and is provided integrally with the bottomed case 31. In this case, the reflection member 33 is provided with a through hole 79 having an inner diameter larger than the diameter of the main body 69, and the support member 5 is installed only in the bottomed case 31.

  As shown in FIG. 5, the bottomed case 31 and the reflecting member 33 are sandwiched between the distal end side portion of the locking portion 71 and the main body 69 of the supporting member 5, so that the supporting member 5 is attached to the reflecting member 33. A configuration may be employed in which the bottomed case 31 and the reflecting member 33 are provided integrally from the bottom of the inner surface.

  By the way, if the support member 5 can also serve as the lamp holder 35 for fixing the CCFL 34, it is preferable because the number of steps for mounting the support member 5 and the like and the cost can be reduced.

  Therefore, a mode in which the support member 5 also serves as the lamp holder 35 for fixing the CCFL 34 will be described with reference to FIG.

  6 includes a light source holding part (lamp holder) 35 for holding the CCFL 34 in addition to the main body part 69 and the engaging part 67, and the light source holding part 35 and the main body part 69. The connecting portion 81 is connected to the connecting portion 81 and is integrally formed by, for example, molding. In addition, when the support member 5a is installed in the backlight device 3 (the bottomed case 31) and the CCFL 34 is installed, the connecting portion 81 is located on the rear side of the CCFL 34.

  The connecting portion 81 is formed in a rectangular thin plate shape, and the main body portion 69, the engaging portion 67, and the light source holding portion 35 are provided on one surface in the thickness direction, and the other in the thickness direction. For example, two locking portions 71 are provided on the surface. The support member 5 a is integrally provided on the bottomed case 31 by these locking portions 71.

  By the way, when the recessed part 65 is formed with the groove | channel, as shown in FIG. 12 (the figure corresponding to FIG. 3 and FIG. 4), you may change the shape of a groove | channel suitably.

  That is, as shown in FIG. 12A, the recess 65 may have a T-shaped cross section, or as shown in FIG. 12B, the recess 65 may have a keyhole shape. Alternatively, as shown in FIG. 12C, the cross-sectional shape of the recess 65 may be formed in a T-shape using a leg trapezoid.

  The cross-sectional shape of the T-shaped groove shown in FIG. 12A (the cross-sectional shape by a plane orthogonal to the longitudinal direction of the groove) is the same as the first rectangular portion 83 located on the back side of the diffusion plate 32. The second rectangular portion 85 is located on the front surface side of the diffusion plate 32. The center of the first rectangular portion 83 in the width direction (the left-right direction in FIG. 12A) and the center of the second rectangular portion 85 in the width direction coincide with each other, and the second rectangular shape. The width of the portion 85 is larger than the width of the first rectangular portion 83.

  When the recess 65 is formed as shown in FIG. 12A, the engaging portion 67 of the support member 5 is formed in a shape that fits into each of the rectangular portions 83 and 85. That is, a columnar (or prismatic) first portion 87 having a diameter substantially equal to the width of the first rectangular portion 83 and a columnar (corner) having a diameter substantially equal to the width of the second rectangular portion 85. A second portion 89 of a columnar shape).

  Note that, as indicated by broken lines in FIG. 12A, the widths of the portions 87 and 89 may be smaller than the widths of the rectangular portions 83 and 85. As a result, the support member 5 restrains the diffusion plate 32 in the thickness direction of the diffusion plate 32 (the vertical direction in FIG. 12A), and the in-plane direction of the diffusion plate 32 (in particular, the left and right in FIG. 12A). The diffusion plate 32 can be supported with play in the direction).

  The cross-sectional shape of the keyhole-shaped groove shown in FIG. 12B (the cross-sectional shape by a plane orthogonal to the longitudinal direction of the groove) is the rectangular portion 91 and the diffusion plate 32 located on the back side of the diffusion plate 32. It is comprised with the circular-shaped part 93 located in the front surface side. The center in the width direction of the rectangular portion 91 and the center in the width direction of the circular portion 93 coincide with each other, and the diameter of the circular portion 93 is larger than the width of the rectangular portion 91.

  When the recess 65 is formed as shown in FIG. 12B, the engagement portion 67 of the support member 5 is formed in a shape that fits into the circular portion 93. That is, it is composed of a cylindrical portion 95 (which may be a prismatic shape) whose diameter is smaller than the width of the rectangular portion 91 and a spherical portion (which may be a cylindrical shape) 97 whose diameter is substantially equal to the diameter of the circular portion 93. ing.

  The cross-sectional shape of the T-shaped groove shown in FIG. 12C (the cross-sectional shape by a plane orthogonal to the longitudinal direction of the groove) is the rectangular portion 99 and the diffusion plate 32 located on the back side of the diffusion plate 32. It is comprised with the isosceles trapezoid shape part 101 located in the front surface side. The isosceles trapezoidal portion 101 has an upper side located on the front surface side of the diffusion plate 32 and a lower side longer than the upper side located on the back side of the diffusion plate 32. The width of the rectangular part 99 is smaller than the length of the lower side of the isosceles trapezoidal part 101. The center in the width direction of the rectangular portion 99 and the center in the width direction of the isosceles trapezoidal shape portion 101 coincide with each other.

  When the recess 65 is formed as shown in FIG. 12C, the engaging portion 67 of the support member 5 is formed in a shape that fits into the rectangular portion 99 and the isosceles trapezoidal portion 101. Yes. That is, the columnar (or prismatic) first portion 103 whose diameter is substantially equal to the width of the rectangular portion 99, and the smaller diameter is approximately equal to the length of the upper side of the isosceles trapezoidal portion 101, and the larger one. And a second portion 105 having a truncated cone shape (or a truncated pyramid shape) that is substantially the same as the length of the lower side of the isosceles trapezoidal portion 101.

  Note that, as indicated by broken lines in FIG. 12C, the widths of the portions 103 and 105 may be smaller than the widths of the rectangular part 99 and the isosceles trapezoidal part 101. As a result, the support member 5 restrains the diffusion plate 32 in the thickness direction of the diffusion plate 32 (the vertical direction in FIG. 12A), and the inner direction of the diffusion plate 32 (in particular, the horizontal direction in FIG. 12A). ) Can support the diffusion plate 32 with play.

  In the above description, the case where the concave portion 65 is a groove has been described as an example. However, the concave portion 65 is not a groove extending in a linear shape, but is present in the form of dots on the back surface of the diffusion plate 32. There may be.

  For example, as shown in FIGS. 8A and 8B, the recess 65 is formed into a short columnar shape (a columnar shape whose height direction matches the thickness direction of the diffusion plate 32) and is supported. The engaging part 67 of the member 5 is formed in a columnar shape substantially equal to the diameter of the recessed part 65, the engaging part 67 is inserted into the recessed part 65, and the diffusion plate 32 is supported by the support member 5 by tight fitting. May be. In addition, Fig.8 (a) is A arrow directional view in FIG.8 (b).

  Further, as shown in FIGS. 9A and 9B, the recess 65 is formed into a short elliptical columnar shape (an elliptical columnar shape whose height direction matches the thickness direction of the diffusion plate 32), and The engagement portion 67 of the support member 5 is formed in an elliptical column shape substantially equal to the inner diameter of the recess 65, the engagement portion 67 is inserted into the recess 65, and the diffusion plate 32 is supported by the support member 5 by an interference fit. There may be. In addition, Fig.9 (a) is A arrow directional view in FIG.9 (b).

  Further, as shown in FIGS. 10A and 10B, the concave portion 65 is formed into a short rectangular column shape (a square column shape whose height direction matches the thickness direction of the diffusion plate 32), and The engagement portion 67 of the support member 5 is formed in a quadrangular prism shape substantially equal to the inner diameter of the recess 65, the engagement portion 67 is inserted into the recess 65, and the diffusion plate 32 is supported by the support member 5 by an interference fit. There may be. In addition, Fig.10 (a) is an A arrow view in FIG.10 (b).

  Further, as shown in FIG. 11, the concave portion 65 of the diffusion plate 32 and the engaging portion 67 of the support member 5 are made of an adhesive or a double-sided tape (preferably an adhesive or a double-sided adhesive having a function as an optical coupling agent). (Tape) 107 may be used to be attached to each other.

  In this case, as shown in FIG. 11 (a), an adhesive or a double-sided tape 107 may be disposed on the side surface and the bottom surface of the columnar engaging portion 67, or as shown in FIG. 11 (b). The adhesive or the double-sided tape 107 may be disposed only on the bottom surface of the engaging portion 67, or the adhesive or the double-sided tape 107 is provided only on the side surface of the columnar engaging portion 67 as shown in FIG. You may arrange.

  In addition, as shown in FIG. 7, the recess 65 may be configured with a recess having a predetermined length (a recess formed by the engaged portion 109 and the insertion portion 111) instead of a groove. The engaged portion 109 has the same cross-sectional shape as the above-described dovetail groove, and the engaging portion 67 of the support member 5 is engaged with the engaged portion 109 so that the diffusion plate 32 is integrated with the support member 5. Support. The insertion portion 111 is a portion for inserting the engagement portion 67 into the recess 65 before the engagement portion 67 of the support member 5 is engaged with the engaged portion 109. The outer diameter of the joint portion 67 is larger. Then, after inserting the engaging portion 67 of the support member 5 into the insertion portion 111, the diffusion plate 32 is moved in one direction with respect to the support member 5 in this plane, and the engaging portion 67 is moved to the engaged portion 109. As a result, the support member 5 supports the diffusion plate 32 integrally.

  7A is a diagram corresponding to FIG. 3, FIG. 7B is a cross-sectional view taken along the line BB in FIG. 7A, and FIG. 7C is a diagram corresponding to FIG. ), And FIG. 7D is a perspective view of the concave portion 65 constituted by the engaged portion 109 and the insertion portion 111.

  By the way, as shown in FIG. 3 and the like, the support member 5 includes a base portion 51 located on the reflector 33 side and a support portion 52 located on the engagement portion 67 side. The base 51 and the support 52 constitute a main body 69. The base portion 51 and the locking portion 71 are made of a white material having high light reflectance, for example, white PC (polycarbonate resin). The support part 52 and the engaging part 67 are made of a transparent material as described above. Then, for example, two materials of transparent PC and white PC are injection-molded or individually injection-molded, and the two parts are assembled to form the support member 5. The entire support member 5 may be formed by injection molding with a transparent PC, and the base member 51 may be coated with white ink.

  Further, as a result of the experiment, if a groove (concave portion 65) having a depth of 1.3 mm or more is provided in the patterned diffusion plate 32 even at the position where the light shielding dots 63 are the least (the position farthest from the CCFL 34), the strength of the diffusion plate 32 is secured. It was also difficult and affected the visibility. Further, even if the support portion 52 and the engaging portion 67 are made of a transparent material, if the width of the portion in contact with the patterned diffusion plate 32 is 10 mm or more, the visibility is affected (the luminance variation in the diffusion plate 32 varies). Result).

  From this experimental result, the diameter of the support portion 52 (the diameter of the upper surface of the engaging portion 67) was φ5.0 mm, the height was 7 mm, the thickness of the base portion 51 was 1.0 mm, and the diameter was φ7 mm.

  Here, since the visibility changes depending on the dot shape 63 of the diffusion plate 32 with the pattern, the distance between the diffusion plate 32 with the pattern and the CCFL 34, and the like, these dimensions change according to the visibility. The dimensions given are not optimal.

  According to the backlight device 3, the recess 65 is provided on the back surface of the diffusion plate 32, and the support member 5 for supporting the diffusion plate 32 is engaged with the recess 65. Therefore, the support member 5 that supports the diffusion plate 32. It is possible to suppress the occurrence of luminance unevenness in the diffusion plate 32 around the engagement portion between the diffusion plate 32 and the engagement portion.

  That is, when the through hole is formed in the diffusion plate, the support member is inserted into the through hole, and the diffusion plate is supported by the support member, the engagement portion between the support member and the diffusion plate and the periphery of the engagement portion There is a possibility that uneven brightness occurs at the diffusion plate (for example, the engaging portion between the support member and the diffusion plate becomes darker than other portions of the diffusion plate). On the other hand, a recess 65 not penetrating to the surface of the diffusion plate 32 (non-penetrating) is provided on the back surface of the diffusion plate 32, and the support member 5 is engaged with the recess 65, so that the light emitted by the CCFL 34 is The diffusion plate 32 enters the diffusion plate 32 from the portion of the diffusion plate 32 where the recess 65 is not provided, goes around the front surface portion of the diffusion plate 32 corresponding to the back surface of the diffusion plate 32 provided with the recess 65, and is supported. The engaging portion between the member 5 and the diffusion plate 32 can be prevented from becoming dark, and the engaging portion between the support member 5 and the diffusion plate 32 that supports the diffusion plate 32 and the diffusion plate around the engaging portion. The occurrence of luminance unevenness at 32 can be suppressed.

  Further, the support member 5 constrains the diffusing plate 32 in the thickness direction and supports the diffusing plate 32 with slight play in the in-plane direction of the diffusing plate 32, thereby providing a pattern with a light-shielding dot 63 printed thereon. A difference in position between the CCFL 34 and the diffusion plate 32 due to deformation of the diffusion plate 32 or deformation due to thermal expansion can be suppressed. That is, the position shift of the diffusion plate 32 with respect to the CCFL 34 can be suppressed at a low cost, and the occurrence of uneven brightness in the diffusion plate 32 can be suppressed.

  Further, according to the backlight device 3, since the support member 5 (the engaging portion 67 and the support portion 52 of the main body portion 69) is made of a transparent material, the concave portion 65 of the diffusion plate 32, the support member 5, Since the optical coupling agent is filled in the gap between the diffusion plate 32 and the support member 5, the relationship between the support member 5 that supports the diffusion plate 32 and the diffusion plate 32 is provided. It is possible to more reliably suppress the occurrence of luminance unevenness in the diffusion plate 32 around the joint portion 67 and the engaging portion 67. In addition, although mentioned later in detail, generation | occurrence | production of a brightness nonuniformity can be suppressed similarly about the reinforcing member 113 (refer FIG. 16 etc.).

  Further, according to the backlight device 3, since the concave portion 65 of the diffusion plate 32 is formed in the above-described shape (shape such as a dovetail shape), the support member can be provided in the thickness direction of the diffusion plate 32 with a simple configuration. 5, the diffusion plate 32 can be restrained, and the occurrence of uneven brightness in the diffusion plate 32 due to the diffusion plate 32 being bent in the thickness direction can be suppressed. Furthermore, when disassembling the backlight device 3 by replacing the CCFL 34 or the like, the support member 5 can be easily attached and detached by sliding it from the patterned diffusion plate 32.

  Further, according to the backlight device 3, since the diffusion plate 32 is formed by injection molding and the recess 65 is formed at the time of injection molding, the diffusion plate 32 having the recess 65 is easily manufactured. can do. Further, since the recess 65 is formed at the time of injection molding, it is easy to make the surface of the recess 65 smooth, and the occurrence of uneven brightness in the diffusion plate 32 can be suppressed.

  Furthermore, according to the backlight device 3, the form of the support member 5 fixed to the back frame (bottomed case) 31 and the reflector (reflecting member) 33 is, as described above, a light reflectance such as a transparent material and white. By using a material having a high color, it is possible to prevent light entering the patterned diffusion plate 32 from being blocked and to prevent light from leaking to the back frame 31 (housing) side. Then, it is possible to prevent the amount of light at the part of the diffusion plate 32 engaged with the support member 5 from being reduced compared to the peripheral part, and the part of the diffusion plate 32 engaged with the support member 5 from becoming dark. it can.

  In the above description, the case where the support member 5 is engaged with the diffusion plate 32 has been described. However, instead of or in addition to the support member 5, the reinforcement for reinforcing the diffusion plate 32 in the recess 65 of the diffusion plate 32. The member 113 may be engaged. The reinforcement member 113 is engaged with the recess 65 of the diffusion plate 32 in the same manner as the support member 5.

  14 is a front view of the liquid crystal display device 1 in which the diffusing plate 32 is provided with the reinforcing member 113, FIG. 15 is a view showing a cross section XV-XV in FIG. 14, and FIG. FIG. 17 is a perspective view of the reinforcing member 113. FIG.

  The reinforcing member 113 shown in FIG. 17A is the reinforcing member 113 shown in FIG. 14, and the reinforcing member 113a shown in FIG. 17B is an isosceles base of the reinforcing member 113 shown in FIG. The shape engaging portion 119 is removed. The reinforcing member 113a shown in FIG. 17B is attached to the back surface of the diffusion plate 32 by using an adhesive having a function of an optical coupling agent or a double-sided tape without using the recess 65.

  Further, the backlight device 3 (liquid crystal display device 1) shown in FIG. 15 and FIG. 16 is not provided with a reflecting member because the inner surface of the bottomed case 31 is a reflecting portion, but the one shown in FIG. Similarly, a configuration in which the reflecting member 33 is provided may be used.

  In the backlight device 3 shown in FIG. 14 and the like, for example, a plurality of reinforcing members 113 are provided on the diffusion plate 32, so that the diffusion plate 32 is reinforced and the bending rigidity of the diffusion plate 32 is increased. Although not shown, the diffusion plate 32 is assumed to be installed on the bottomed case 31 or the like using the support member 5 as described above.

  The reinforcing member 113 is made of, for example, a transparent material such as acrylic resin, is formed in an elongated rectangular parallelepiped shape, and functions as a rib of the diffusion plate 32. That is, the longitudinal direction of the reinforcing member 113 extends in one direction in the in-plane direction of the diffusion plate 32 (for example, the width direction of the rectangular diffusion plate 32; the direction orthogonal to the longitudinal direction of the CCFL 34), and the height of the reinforcing member 113 One portion (engagement portion 119) in the direction engages with the recess 65, and the reinforcing member 113 is provided integrally with the diffusion plate 32. The other end in the height direction of the reinforcing member 113 and the bottomed case 31 are slightly separated from each other (see an interval L3 shown in FIG. 15).

  The reinforcing member 113 may not be provided integrally with the diffusion plate 32, but may be provided with play as in the case of the support member 5. That is, in a state in which the reinforcing member 113 is provided on the diffusion plate 32, the reinforcing member 113 has a height direction (vertical direction in FIG. 15) and a thickness direction (a direction orthogonal to the paper surface in FIG. 15) with respect to the diffusion plate 32. However, the reinforcing member 113 may have a certain amount of play in the longitudinal direction (the left-right direction in FIG. 15) with respect to the diffusion plate 32. That is, the reinforcing member 113 may move with a predetermined resistance in the longitudinal direction with respect to the diffusion plate 32.

  Further, instead of providing the columnar support member 5, the reinforcing member 113 may have a function as a support member. That is, the value of the interval L3 shown in FIG. 15 may be set to “0”, and the other end in the height direction of the reinforcing member 113 may be integrally provided in the bottomed case 31.

  When the reinforcing member 113 also has a function as a supporting member, the reinforcing member (supporting member) 113 restrains the diffusion plate 32 in the thickness direction as in the case of the supporting member, and the surface of the diffusion plate 32 The structure may be supported in the inward direction with slight play.

  As described above, the reinforcing member 113 (first rib 115) extends in a direction intersecting the longitudinal direction of the CCFL 34 that is a line light source (for example, a direction orthogonal thereto) and is provided on the back surface of the diffusion plate 32. Yes. The protrusion amount (protrusion height) of the first rib 115 from the diffusion plate 32 is small at a portion near the CCFL 34 and large at a portion away from the CCFL 34. That is, the protrusion amount L4 shown in FIG. 15 is about 1 mm immediately above and near the CCFL 34.

  A plurality of the first ribs 115 are provided at an interval of 100 mm (an interval of 100 mm in the vertical direction in FIG. 14), but the installation interval and the number of the first ribs 115 are the deflection and visibility of the diffusion plate 32. You may decide while confirming.

  According to the backlight device 3, the protrusion amount of the reinforcing member 113 (first rib 115) from the diffusion plate 32 is small at a portion near the CCFL 34 and large at a portion away from the CCFL 34. In addition, the rigidity of the diffusing plate 32 can be increased to increase the installation accuracy of the diffusing plate 32, and the occurrence of uneven brightness in the diffusing plate 32 can be suppressed.

  By the way, as shown in FIGS. 18 and 19, the reinforcing members 113 may be provided in a lattice shape. The reinforcing member 113 shown in FIGS. 18 and 19 is formed in a lattice shape with a plurality of first ribs 115 and a plurality of second ribs 117. As described above, the first rib 115 extends in a direction orthogonal to the longitudinal direction of the CCFL 34. The second rib 117 extends in the longitudinal direction of the CCFL 34. The ribs 115 and 117 are integrally formed by, for example, injection molding. An engaging portion 119 having an isosceles trapezoidal cross section is provided at one end in the height direction of the second rib 117, and this engaging portion 119 engages with the dovetail groove 65 of the diffusion plate 32. It is like that.

  Instead of the second rib 117, an engaging portion having an isosceles trapezoidal cross section is provided at one end in the height direction of the first rib 115, and this engaging portion is formed in the dovetail groove 65 of the diffusion plate 32. You may come to engage.

  Moreover, you may provide the engaging part 119 in each of each rib 115,117. In this case, in order to assemble each rib 115,117 to the diffusion plate 32, it is assumed that each rib 115,117 is separable as shown in FIG. Furthermore, when each rib 115,117 is separable, as shown in FIG. 21, the rectangular uneven | corrugated | grooved part 121 may be formed in the junction part of each rib 115,117.

  Note that, as described above, the first rib 115 is used to reduce the deflection due to the weight of the diffusion plate 32 and prevent the diffusion plate 32 itself from becoming heavy and to suppress the occurrence of uneven brightness in the diffusion plate 32. Among them, the thickness L4 (see FIG. 15) of the one existing near the CCFL 34 is reduced to 1 mm.

  Further, as already understood from the description of FIGS. 8 to 12, as shown in FIG. 22, the cross-sectional shapes of the concave portion 65 of the diffusion plate 32 and the engaging portion 123 of the reinforcing member 113 are made rectangular. It may be formed.

  In addition, when the reinforcing member 113 as shown in FIG. 17B is attached to the diffusion plate (flat diffusion plate with no recess 65 formed) 32 with an adhesive or the like, The position needs to be correct. Therefore, the marking 125 may be provided on the diffusion plate 32 at the same time when the dots 63 of the diffusion plate 32 are printed (see FIG. 23).

  In addition, the thickness L5 (see FIG. 19) of the reinforcing rib 117 parallel to the CCFL 34 is reduced, and the reinforcing rib 115 extending perpendicularly to the CCFL 34 has a thickness L6 corresponding to a reduction in the height L4 of the CCFL 34 portion. (See FIG. 19) is thicker than the thickness L5.

  Further, as a general configuration of the liquid crystal display device 1, an optical sheet 4 for improving the viewing angle is interposed between the liquid crystal panel (cell) 2 and the diffusion plate 32. These also require a certain level of flatness, and if there are large irregularities in the film plane, the luminance becomes uneven and the quality of the liquid crystal display device 1 is degraded. Therefore, a reinforcing member 113 is provided on the back side of the diffusion plate 32.

  Further, since the surface on which the light shielding dots 63 are printed is desirably a surface facing the CCFL 34 in order to obtain efficient light shielding properties, the dots 63 and the marking 125 are printed on the surface on which the reinforcing member 113 is provided. become. Further, in order to prevent the occurrence of luminance unevenness of the diffusion plate 32, the reinforcing member 113 needs to be made of a transparent body with respect to the diffusion plate 32 made of milky white resin. The reinforcing member 113 is made of a different material, and the diffusing plate 32 and the reinforcing member 113 are fixed to each other by using dovetail grooves or by adhesion or double-sided tape.

  The height of the second rib 117 (the amount of protrusion from the diffuser plate 32) should be as large as possible to increase the rigidity, and is equivalent to the distance between the diffuser plate 32 and the reflector 33 as shown in FIG. Although the height (9 mm) is desirable, the height of the second rib 117 needs to be designed in consideration of assembly tolerances, and is slightly smaller than 9 mm.

  The thickness L5 of the second rib 117 (see FIG. 19) is such that when the distance between the CCFLs 34 is 23 mm, the portion where the second rib 117 is provided becomes darker than the surroundings even if it is 10 mm, even though it is a transparent material. Results that affect sex were obtained. Therefore, the thickness of the second rib 117 is set to 9 mm. The length of the second rib 117 is the same as the length of the diffusion plate 32. However, it is desirable that the length of the second rib 117 be as long as possible without affecting the assembly. The second rib 117 is arranged at the center between the CCFLs 34 (the place where the light shielding area of the diffusion plate 32 is the smallest), the CCFL 34 and the second rib 117 extend in parallel, and the longitudinal direction of the CCFL 34 and the second direction The rib 117 is in the same direction.

  The first rib 115 is thin at 1 mm at a location of 5 mm (over a length of 10 mm) with the center directly above the CCFL 34, and the height is slightly smaller than 9 mm at other locations. It is a value (see FIG. 18). The thickness L6 (see FIG. 19) of the first rib 115 is 30 mm, and the length is the same as the width direction of the rectangular diffusion plate 32.

  Each of the ribs 115 and 117 is fixed to the diffusing plate 32 by an adhesive having optical coupling properties (for example, product name Super X manufactured by Cemedine Co., Ltd.) or a double-sided tape as in the support member 5. In this case, it may be engaged with the concave portion 65 of the diffusion plate, or the flat plate-shaped diffusion plate 32 not provided with the concave portion 65 is engaged with the concave portion 65 as shown in FIG. The structure which provided each rib 115,117 in which the part is not provided may be sufficient.

  Further, when the ribs 115 and 117 are installed on the diffusion plate 32, a cut is provided in at least one of the ribs 115 and 117 so that the position can be easily obtained. The ribs 115 and 117 may be connected to a predetermined position of the diffusion plate 32 by assembling in accordance with (not shown) (by installing the ribs 115 and 117 on the diffusion plate 32).

  The diffusion plate 32 and each of the ribs 115 and 117 can be fixed by fixing the rib 115 or the rib 117 to the diffusion plate 32 and then fixing the other rib. After assembling, fixing to the diffusion plate 32 is desirable from the viewpoint of ease of positioning and man-hours.

  Further, as already understood, in order to facilitate positioning of the ribs 115 and 117 to the diffusion plate 32, as shown in FIG. 22, for example, a surface on which light shielding dots are printed (FIG. 22). A slit (a slit forming the concave-convex portion 123) that does not affect the visibility on the lower surface of the diffusion plate 32 in FIG. 1, for example, a slit having a groove width of 1 mm and a depth of 0.5 mm is formed. Alignment can be facilitated by using the second rib 117 having a protrusion that engages with the protrusion (protrusion forming the uneven portion 123).

  Furthermore, as shown in FIG. 24, the height of the first rib 115 may be the lowest just above the CCFL 34, and the height of the first rib 115 may gradually increase as the distance from the CCFL 34 light source increases. That is, in the backlight device 3 shown in FIG. 15, the first rib 115 is provided with a rectangular cutout to reduce the height of the first rib 115 in the portion where the CCFL 34 is provided. As shown in FIG. 24, for example, a semicircular cutout 127 may be provided, and the height of the first rib 115 may be changed smoothly.

  In addition, it replaces with the recessed part 65 in the diffuser plate of the backlight apparatus 3 mentioned above, a support member 5 and the reinforcement member 113 are engaged with this convex part, the diffuser plate 32 is supported, and reinforcement is carried out. May be. In addition, the said convex part shall be formed when the diffusion plate is injection-molded, and shall be integrally formed with the main body of the diffusion plate. More preferably, the convex portion is formed in an elongated shape as in the case of the groove, and the shape of the cross section by a plane orthogonal to the longitudinal direction of the convex portion is a constant shape. To do. Further, it is desirable that the convex portion is made of a material that transmits light by two-color molding or the like.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal panel 3 Backlight apparatus 4 Optical sheet 5, 5a Support member 31 Bottomed case 32 Diffusion plate 33 Reflective member 34 CCFL
35 Lamp holder 65 Recess (Dovetail groove)
67 Engaging portion of support member 5 69 Main body portion of support member 5 113, 113a Reinforcing member 115 First rib 117 Second rib

Claims (3)

A housing that is open on one side;
A light source disposed in the housing;
A diffusion plate that is disposed on the open surface of the housing, has a recess formed on the surface on the light source side, and diffuses and transmits light emitted from the light source;
A support member having one end engaged with the recess of the diffusion plate and the other end engaged with the housing;
I have a,
The width of the cross-sectional shape in said recess of said diffusion plate, a backlight device that is narrower in the incident area of the light. A housing that is open on one side;
A light source disposed in the housing;
A diffusion plate that is disposed on the open surface of the housing, has a recess formed on the surface on the light source side, and diffuses and transmits light emitted from the light source;
A support member having one end engaged with the recess of the diffusion plate and the other end engaged with the housing;
Have
The light source is a linear light source;
The support member extends in a direction intersecting the line light source and is provided on the light source side of the diffuser plate, and a protruding amount from the diffuser plate is small at a portion near the light source, and the light source backlight equipment that is large at a site away from. The liquid crystal display device characterized by having a backlight device 請 Motomeko 1 or claim 2, wherein.

Images