JP5029413B2 - Backlight device - Google Patents

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 etc.”). As a fixing method of the optical sheet in the conventional backlight device, the optical sheet is used. The method (patent document 1) etc. which fasten an optical sheet to a support plate etc. with the screw etc. using the provided through-hole have been adopted. In addition, a method of fixing the light guide plate etc. to the support plate, etc., forming a concave portion of a predetermined shape on the support plate etc., forming the light guide plate etc. into a shape corresponding to the concave portion, and fitting the light guide plate etc. into the concave portion There is a method (Patent Document 2) or the like for fixing.
JP 2003-346536 A JP 2000-30519 A

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, when used in an environment such as an automobile where the change in temperature difference is large, the light guide plate and the optical sheet may bend and deform due to expansion and contraction. It becomes a problem. 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 such a problem of interference between the members, rattling occurs when the clearance is increased, and abnormal noise is likely to occur. In particular, abnormal noise due to rattling becomes noticeable in a backlight device used in an environment with a lot of vibration such as in an automobile. In particular, a high-class vehicle having high sound insulation between the vehicle interior and the exterior of the vehicle interior is not preferable because such abnormal noise becomes more prominent.
On the other hand, when the clearance is increased, foreign matters such as dust are likely to enter. The intrusion of foreign matter is not preferable because it affects the optical characteristics of the backlight device and causes generation of turbulent light and a decrease in luminance.
In view of the above, it is an object of the present invention to prevent the generation of abnormal noise while solving the problem of interference caused by the expansion and contraction of the light guide and the optical sheet in the backlight device. Another object is to prevent foreign substances such as dust from entering the apparatus.

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 face from the front, and
An optical sheet disposed on the front side of the light guide plate, and a liquid crystal panel holding member disposed on the front side of the optical sheet,
The optical sheet has a notch,
The light guide plate and the holding member are joined via a cushioning material at a position corresponding to the notch portion of the optical sheet.
This is a backlight device (first configuration).

In the first configuration, the light guide plate and the liquid crystal panel holding member are joined via the cushioning material. Thereby, the interference between the light guide plate and the liquid crystal panel holding member is alleviated, and the occurrence of rattling and the accompanying noise are prevented. Even when the light guide plate or the liquid crystal panel holding member expands and contracts and the deflection occurs, interference between the light guide plate and the liquid crystal panel holding member is mitigated by the cushioning material, and rattling is prevented. This is particularly effective when used in an environment with a lot of temperature changes and vibrations. Further, the light guide plate and the liquid crystal panel holding member are joined at a position corresponding to the notch portion of the optical sheet, and the optical sheet is held in a floating state between the light guide plate and the liquid crystal panel holding member. Normally, a clearance is provided in consideration of expansion and contraction of the optical sheet and other members. However, if the clearance is too large, positional deviation or rattling occurs. By holding the optical sheet in a floating state, such a clearance can be minimized, and the occurrence of wobbling and misalignment of the optical sheet can be prevented. Further, since the optical sheet is mounted by a simple method of placing on the light guide plate and covering the liquid crystal panel holding member, the assembling work is not complicated.
In this specification, the light guide plate and the liquid crystal panel holding member are joined via a buffer material. The term “joining” used here refers to the contact between the light guide and the buffer material, and the liquid crystal panel holding member and the buffer material. Means to be installed in a state of contact. For example, the buffer material can be bonded to or pressed against the light guide and the liquid crystal panel holding member.

  A plurality of optical sheets can be laminated for the purpose of performing desired optical control. In this case, the cut portions of the optical sheets are provided at the same position in the stacked state, and the entire plurality of optical sheets are held in a floating state as described above.

  In the second configuration of the present invention, in the first configuration, the light guide plate includes a rib at a position corresponding to the cutout portion of the optical sheet, and a cushioning material is disposed between the rib and the liquid crystal panel holding member. . According to the second configuration, the gap between the light guide plate and the liquid crystal panel holding member can be secured by the rib of the light guide plate. As a result, even when the light guide plate and the liquid crystal panel holding member are bent due to expansion / contraction, the optical sheet is reliably held in a floating state, and interference between the light guide plate and the liquid crystal panel holding member is prevented. It is surely alleviated and the generation of rattling and accompanying noise is prevented.

  In the third configuration of the present invention, in the first or second configuration, the upper end surface of the light guide plate is a light incident surface, the liquid crystal panel holding member is a frame shape, and the notch portion of the optical sheet is formed of the light guide plate. It is provided along the lower edge. In this configuration, since the notch is provided at a position away from the light incident surface, the joint between the light guide plate and the liquid crystal panel holding member is provided at a position away from the light incident part. Thereby, the influence (light leakage, generation | occurrence | production of a bright line, irregular reflection, etc.) which a junction part has on the incident light of a light-guide plate is relieved. As a result, the utilization factor of light is improved, which contributes to the high brightness of the backlight. In particular, when a rib is provided at a position corresponding to the notch portion of the optical sheet of the light guide plate (that is, in the case of the second configuration), leakage of bright lines and light by the rib formed integrally with the light guide. However, by providing a rib at a position away from the light incident portion, leakage of bright lines and light can be prevented.

  In the second configuration of the present invention, the length of the rib provided on the light guide plate (the length in the longitudinal direction of the light guide plate) is about 0.4 to 0.9 times the length of the lower edge of the front surface of the light guide plate. Can be doubled. Thus, by forming the rib long in the length direction, the joint area (via the buffer material) between the light guide plate and the liquid crystal panel holding member is increased and stabilized, and the generation of abnormal noise is further prevented.

  The height of the rib provided on the light guide plate may be a height that does not cause unnecessary interference between the liquid crystal panel holding member and the optical sheet. If the rib is so low that it does not reach the thickness of the optical sheet, the optical sheet cannot be held in a floating state when the liquid crystal panel holding member is mounted. On the other hand, if the rib is too high, the clearance in the thickness direction becomes excessive, which contributes to the shakiness of the optical sheet. The height of the rib can be determined in consideration of the thickness of the optical sheet to be used, the number of optical sheets used, the thickness of the buffer material, etc., for example, one sheet having a thickness of about 0.115 mm, When two sheets having a thickness of about 0.155 mm are used, the height of the rib can be about 0.55 mm to about 0.80 mm, preferably 0.60 mm to 0.70 mm.

  The cushioning material used in the present invention is not particularly limited as long as it is a material that absorbs impact. Examples thereof include synthetic resins such as PET and polyimide, and natural rubber. It is preferable that both surfaces of the buffer material are adhesive surfaces, that is, a double-sided tape. This is because the occurrence of rattling can be prevented by absorbing the impact and adhering the light guide plate and the liquid crystal panel holding member. Especially, the double-sided tape which uses PET resin as a base material is preferable. This is because PET resin is less likely to generate foreign matter due to deterioration over time. The thickness of the buffer material is not particularly limited, but may be, for example, 0.050 to 0.700 mm, preferably 0.065 to 0.500 mm, and most preferably about 0.085 mm.

  The buffer material is preferably provided so as to abut on the entire front surface of the rib of the light guide (that is, the surface on the liquid crystal panel holding member side). This is because the light guide and the liquid crystal panel holding member are more stably fixed and the holding power of the optical sheet is increased.

  The present invention further includes, as a fourth configuration, in the first, second, or third configuration, a first small protrusion formed on the left edge of the front upper end portion and a second small protrusion formed on the right edge of the front upper end portion. The light guide plate includes a small protrusion and a third small protrusion formed at the reference position of the front lower end portion, and is a hole through which the first small protrusion is inserted and is formed at a position corresponding to the first small protrusion. A first hole, a hole through which the second small protrusion is inserted and a second hole formed at a position corresponding to the second small protrusion, and a notch through which the third small protrusion is inserted and the third small protrusion The optical sheet includes a first notch formed at a position corresponding to the first hole, the first hole and the second hole are long holes in the left-right direction, and the first notch is a long notch in the up-down direction. A backlight device is provided.

  According to the fourth configuration, the optical sheet is formed by inserting each small protrusion provided on the front surface of the light guide plate into the first hole, the second hole, and the first notch formed in the optical sheet. Is held by the light guide plate. Since the first hole and the second hole provided on the left and right of the upper end of the light guide plate are long holes in the left and right direction, the position in the left and right direction when the light guide plate and the optical sheet are expanded and contracted while preventing the displacement in the vertical direction Can follow changes. On the other hand, since the first cutout is a cutout that is long in the vertical direction, it is possible to follow the vertical position change during expansion / contraction of the light guide plate and the optical sheet while preventing the horizontal displacement.

  In the fourth configuration, due to the structure, interference between the third small protrusion of the light guide plate and the liquid crystal panel holding member may occur, and abnormal noise may occur. On the other hand, providing a cushioning material on the third small protrusion is not practical because of problems such as peeling and dropping. Therefore, in this configuration, it is preferable to provide the rib of the light guide plate described above in the vicinity of the third small protrusion. This is because the interference between the third small protrusion and the liquid crystal panel holding member can be reduced by the cushioning material provided between the rib of the light guide plate and the liquid crystal panel holding member. In particular, it is preferable to provide the ribs of the light guide plate of the present invention on both the left and right sides of the third small protrusion. This is because the interference between the third small protrusion and the liquid crystal panel holding member can be further reduced. Thereby, generation | occurrence | production of unusual noise is prevented further.

  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 (liquid crystal panel holding member) 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 this 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 notched. Thus, a pair of left and right upper step surfaces 35 are formed. The upper step surface 35 functions as a barrier against dust. That is, as can be seen from FIG. 21 showing the state after the backlight device 1 is assembled, the upper end step surface 35 prevents dust from entering the light incident area 31 side. 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 way, a structure that is strong against dust is obtained. The side end step surface 36 is used as a receiving seat for the upper holder 60. On the front side of the light guide 30, four rib-shaped small protrusions 101 are provided at equal intervals along both left and right edges. Each optical sheet 40, 50, 51 described later has a notch 106 corresponding to the rib-like small protrusion 101.

The light guide 30 is provided with ten pins (small protrusions). The arrangement of each pin is as follows. As shown in FIG. 15, at the upper end portion of the front surface 32, both left and right edges (first pin 37a and second pin 37b), center (sixth pin 37f), intermediate between the first pin 37a and the sixth pin 37f ( Pins (small protrusions) are provided at positions of the seventh pin 37g) and the middle (eighth pin 37h) between the second pin 37b and the sixth pin 37f. On the other hand, at the lower end of the front surface 32 of the light guide 30, both left and right edges (fourth pin 37d and fifth pin 37e), center (third pin 37c), intermediate between the fourth pin 37d and third pin 37c (first 9 pins 37i) and intermediate positions between the fifth pin 37e and the third pin 37c (tenth pin 37j) are provided. In this embodiment, the distance between the pins (first pin 37a, second pin 37b, sixth pin 37f, seventh pin 37g, and eighth pin 37h) formed at the upper end and the upper end is about 3.7 mm. The distance between the pins (fourth pin 37d, fifth pin 37e and third pin 37c) formed at the lower end and the lower end is about 0.5 mm. As will be described later, these pins cooperate with holes and cutouts formed in the optical sheet (diffusion sheet 40, vertical eye prism sheet 50, horizontal eye prism sheet 51) to position and hold the optical sheet. Demonstrates functions such as optical sheet deflection prevention. Each of the pins 37a to 37j has a columnar shape with a height of about 0.7 mm, and the diameter is as follows. That is, the pins 37a to 37c have a diameter of about 1.2 mm, the pins 37d and 37e have a diameter of about 2.0 mm, the pins 37f to 37h have a diameter of about 1.0 mm, and the pins 37i and 37j have a diameter of about 1.5 mm. The shape of the pins 37a to 37j 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 size of the pins 37a-j is not particularly limited. The diameter of the pins 37a to j is, for example, 0.5 mm to 3.0 mm, and the height is similarly, for example, 0.3 mm to 1.0 mm.
The positions where the pins 37a to 37j 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 seventh pin 37g and the eighth pin 37h, and the ninth pin 37i and the tenth pin 37j.

At the lower end of the light guide 30, ribs 38a to 38d are provided. The ribs 38a to 38d have a width of about 1.0 mm and a length of about 45 mm. The rib 38a is provided at a position of about 0.3 mm from the lower end of the light guide 30 in parallel with the lower end, and one end (end on the center side) is provided at an interval of about 7 mm from the center of the lower end. The ribs 38b are also provided in parallel to the lower end at a position of about 0.3 mm from the lower end of the light guide 30, and are disposed at an interval of about 3 mm from the rib 38a. The ribs 38c and 38d are provided symmetrically to the ribs 38a and 38b, respectively. As a result, the ribs 38 a to 38 d are formed on a straight line along the lower end of the light guide 30.
A microlens pattern is formed on the back surface (the surface opposite to 32a) of the light guide. The microlens pattern is a microlens having a lens diameter of about 150 μm and a lens height of about 50 μm arranged in a dot matrix at a pitch of about 200 μm.

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 or notches are formed at positions corresponding to the pins 37a to 37j and the ribs 38a to 38d in the same manner. Further, notches 106 are formed in the optical sheets 40, 50 and 51 so as to correspond to the rib-like small protrusions 101 of the light guide 30. 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, holes 41a, 41g, 41f, 41h, and 41b are formed in five places in order from the left side of the paper at the upper end of the diffusion sheet 40, and are cut in five places from the left side of the paper in the lower end. Notches 41d, 42a, 41c, 42b, and 41e are formed. The upper end holes 41a, 41g, 41f, 41h, and 41b all follow the positioning and holding of the diffusion sheet 40 with respect to the light guide 30, and the change in position in the left-right direction accompanying the expansion and contraction of the light guide 30 and diffusion sheet 40. (Left / right position adjustment) and up / down position shift prevention. The holes 41a, 41g, 41f, 41h, and 41b are all long holes in the left-right direction so that these functions can be exhibited (see the A and B partial enlarged views in FIG. 23). The specific hole diameter is about 1.5 mm in the vertical direction and about 3.0 mm in the horizontal direction.
A notch (first notch 41 c) at the center of the lower end portion positions and holds the diffusion sheet 40 with respect to the light guide 30, and follows a change in position in the vertical direction accompanying expansion and contraction of the light guide 30 and the diffusion sheet 40. (Position adjustment in the vertical direction) and the three functions of preventing the horizontal displacement. In order to exhibit these functions, the third hole 41c is a vertically long cutout that is long in the vertical direction (see the C-part enlarged view of FIG. 23). The specific shape of the notch is a shape that is about 1.5 mm in the left-right direction (width) and is cut about 4.5 mm in the vertical direction from the lower end.
The cutouts (second cutout 41 d and third cutout 41 e) formed at the left and right edges of the lower end are used to support the diffusion sheet 40. That is, by providing the notches, it is ensured that the left and right edges of the lower end of the diffusion sheet 40 are arranged at desired positions when the diffusion sheet 40 is placed on the light guide. 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. The notch has a rectangular shape with a width of about 5.0 mm and a height of about 4.5 mm so that it can follow changes in position in the left-right direction and up-down direction accompanying expansion and contraction of the light guide 30 and the diffusion sheet 40.
The fourth cutout 42a is provided between the first cutout 41c and the second cutout 41d. The fourth cutout 42a is a horizontally long rectangular cut having a width of about 100 mm and a height of about 4.5 mm. The fifth cutout 42b has the same shape as the fourth cutout 42a and is formed symmetrically.

  As shown in FIG. 23, diffusion is achieved by inserting corresponding pins 37a, 37g, 37f, 37h, 37b and 37c into the above holes 41a, 41g, 41f, 41h and 41b and the first cutout 41c. The sheet 40 is held by the light guide 30 in a positioned state. It can be seen that the formation positions of the holes 41a, 41g, 41f, 41h, and 41b are set so that the corresponding pins are located at substantially the center thereof. Further, as shown in FIG. 23, ribs 38a to 38d on the lower end portion of the light guide 30 are positioned in the second cutout 42a and the third cutout 42b. That is, the second notch 42a and the third notch 42b function as a relief area for the ribs 38a to 38d, and the diffusion sheet 40 and the ribs 38a to 38d are prevented from interfering unnecessarily.

  The sizes of the holes 41a, 41g, 41f, 41h, 41b and the cutouts 41c, 42a, 42b are the sizes of the pins 37a, 37g, 37f, 37h, 37b, 37c, the light guide 30 of the ribs 38a to 38d, and the diffusion sheet. It is set in consideration of the thermal expansion coefficient of 40 and the like, and the one shown in this embodiment is only an example. If the example of the magnitude | size of each hole and a notch is shown, about the hole 41a, 41g, 41f, 41h, 41b, when inserting a pin, it will be 0 mm-0.45 mm at a time, for example, 0 mm-0.2 mm preferably The clearance is secured to the left and right, for example, 0.4 mm to 1.03 mm, preferably 0.8 mm to 1.03 mm. For the first notch 41c, when the pin is inserted, for example, 0.28 mm to 1.08 mm vertically, preferably 0.85 mm to 1.08 mm, and right and left, eg 0 mm to 0.45 mm, preferably 0 mm. The clearance is set to ensure a clearance of about 0.2 mm. About the 2nd notch 42a, it is 1.0-5.0 mm on the upper side of rib 38a, 38b, for example, Preferably it is 0.5-1.5 mm, for example, it is 1.0-5.0 mm on the right and left, Preferably it is 0.5. The size is such that a clearance of ˜1.5 mm is ensured.

  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, a hole (positioning / holding, following a change in position in the left-right direction, and a vertical displacement prevention hole) that exhibits the same function as each hole is provided between the hole 41a and the hole 41g, and between the hole 41g and the hole. One or more may be provided between 41f, between holes 41f and 41h, and between 41h and holes 41b.

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). In addition, 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 37 is provided with a tongue-like locking leg 67a extending downward at a substantially central position. Each wide extending portion 67 is also provided with a positioning projection 67b on the upper surface side. Furthermore, the left and right edge portions on the upper surface side of the upper holder 60 protrude upward, and a support wall surface 65c having a height of 3.2 mm is formed.

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 circuit board assembly 70 is connected to a control circuit and a power source via a connector 73. 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. A connector 73 is also provided in the rear end region. Reference numeral 71 e indicates a side end surface of the substrate 71.
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.

  Next, the configuration of the TFT holder (liquid crystal panel holding member) 90 will be described in detail with reference to FIGS. A front view of the TFT holder 90 is shown in FIG. 36 (A), a bottom view is shown in FIG. 36 (B), and a rear view is shown in FIG. 36 (C). The TFT holder (liquid crystal panel holding member) 90 is a frame-shaped member (FIG. 1), on which a TFT panel (not shown) 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. Specifically, as shown in FIG. 36A, when viewed from the front, the TFT holder 90 has an upper end portion 93 having a width of about 5.0 mm, a left and right frame portion 94 having a width of about 4.0 mm, and a width of about 8 mm. It consists of a lower end 95 of 0.0 mm. Further, a double-sided tape 96 having a width of about 3.0 mm is attached along each side on the inner side of the front. A TFT panel is attached via the double-sided tape 96. As shown in FIG. 36C, double-sided tapes 97a and 97b having a width of about 2.5 mm and a length of about 100.0 mm are affixed to the back surface of the lower end portion 95 (that is, the surface on the light guide 30 side). Yes. The double-sided tape 97 a is provided at a position about 6.0 mm away from the center of the lower end portion 95 along the lower end of the TFT holder 90. A double-sided tape 97b is provided at a position symmetrical to the double-sided tape 97a. In the assembled state, these double-sided tapes 97a and 97b are bonded to the ribs 38a to 38d provided at the lower end portion of the light guide 30 described so that the light guide 30 and the TFT holder 90 are joined. In addition, all the double-sided tapes used here are double-sided tapes based on PET resin, and the thickness thereof is about 0.085 mm.

  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. 37). 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. 38 and 39). 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. 38, FIG. 39), the locking leg 67a is locked to the tip of the tongue piece 14 of the shield case 10. 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 37 to 39). 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. 39). 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. .

  A sectional view taken along the line P-P in FIG. 2 is shown in FIGS. 40A and 40B, and a sectional view taken along the line Q-Q is shown in FIG. When the upper holder 60 is attached, 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. 40A). Thus, 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. 40A, 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, 41g, 41f, 41h, 41b and the first notches 41c provided in each optical sheet are inserted into the corresponding pins 37a, 37g, 37f, 37h, 37b, and 37c of the light guide 30 ( (See FIGS. 22 and 23). At this time, the left and right reference is determined by the pin 37c and the first notch 41c, and between the pin 37a and the hole 41a, between the pin 37g and the hole 41g, between the pin 37f and the hole 41f, and between the pin 37h and the hole 41h. And the positioning of an up-down direction is performed between the pin 37b and the hole 41b. In this way, the optical sheets 40, 50 and 51 are positioned on the light guide 30.

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. 40B), 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. Accordingly, the ribs 38a to 38d at the lower end portion of the light guide 30 and the double-sided tapes 97a and 97b attached to the inner side surface of the lower end portion 95 of the TFT holder 90 are adhered to each other so that the TFT holder 90 and the light guide 30 are connected. They are joined (see FIG. 40 (c)). As a result, each optical sheet is supported by the light guide 30 but is not fixed by the double-sided tapes 97a and 97b. Therefore, the optical sheet is held in a floating state between the light guide 30 and the TFT holder 90.
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, by fixing the ribs 38a to 38d of the light guide 30 and the TFT holder 90 with the double-sided tapes 97a and 97b, the double-sided tapes 97a and 97b function as a cushioning material. It is possible to alleviate the interference and prevent rattling and the occurrence of abnormal noise. By the way, there is a possibility that the noise between the pin 37c at the center of the lower end of the light guide 30 and the TFT holder 90 is likely to be generated due to the structure. However, it is not practical to provide a buffer material on the pin 37c because there is a problem of peeling and dropping. In this embodiment, the ribs 38a to 38d are arranged symmetrically on both sides of the lower edge of the light guide 30, so that the interference generated between the pin 37c and the TFT holder 90 is surely prevented. Sound generation is reliably prevented. Further, since the ribs 38a to 38d are formed at the lower end of the light guide 30 away from the light incident area 31 (upper end), the influence on the light incident from the light incident area 31 (bright lines, generation of turbulent light, light leakage). ) Is reduced. This prevents a decrease in light utilization rate.

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 holes 41a, 41g at positions where the influence of expansion / contraction in the vertical direction is negligible due to the influence of expansion / contraction in the horizontal direction (that is, the position change in the horizontal direction is remarkable) and the fixed end side. 41f, 41h, and 41b (see FIGS. 22 and 23) are long holes in the left-right direction and have a minimum vertical clearance to follow the position change in the left-right direction while preventing vertical displacement. I can do it. Similarly, it is greatly affected by expansion / contraction in the vertical direction (that is, the positional change in the vertical direction becomes significant), and since it is at the reference position (center) in the horizontal direction, the position can be ignored where the influence of expansion / contraction can be ignored. The notch 41c is long in the vertical direction and the vertical clearance is minimized so that it can follow the vertical position change while preventing the horizontal displacement.
By designing each of the holes 41a, 41g, 41f, 41h, 41b and the notch 41c as described above, the positional relationship between the light guide 30 and the optical sheet changes with the expansion / contraction of the light guide 30 and / or the optical sheet. When this occurs, in each of the holes 41a, 41g, 41f, 41h, 41b at the upper end, the pins 37a, 37g, 37h, 37f, 37b move in the left-right direction within the first hole 41a and the second hole 41b at the upper end. (See FIG. 23), the pin 37c moves up and down in the notch 41c at the center of the lower end. As a result of such pin movement, no stress is applied to the optical sheet. On the other hand, since each hole is provided with an appropriate clearance, it is possible to prevent displacement of the entire optical sheet.
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. Moreover, since the base material of the double-sided tapes 97a and 97b is a PET resin, it is difficult for foreign matters such as dust due to deterioration to occur. Thereby, quality deterioration, such as generation | occurrence | production of a disturbance light and a fall of a brightness | luminance, can be prevented.

  FIG. 41A is a plan view showing a modification example of the light guide 30 and the optical sheet. FIG. 41B is an enlarged view of portion A in FIG. 41A, and FIG. 41C is a cross-sectional view taken along the line BB in FIG. 41A. As shown in FIG. 41, the light guide 30 is provided with a plurality of rib-like small protrusions 101 at equal intervals along both the left and right edges on the front side. Corresponding to this, notches 106 are also formed in the optical sheets 40, 41 and 50. 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.

  FIG. 42 schematically shows the stacking order of the light guide 30, the diffusion sheet 40, the vertical prism sheet 50, and the horizontal prism sheet 51. 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. FIG. 43 shows a front view of the vicinity of the left side of the lower end in a state where the three optical sheets 40, 50, 51 are sequentially laminated. In the horizontal eye prism sheet 51, a part near the left side of the lower end is cut out to form a window portion 52. The shape of the window 52 is a substantially trapezoid in which the upper side and the lower side are parallel, the left side 51a is a side substantially perpendicular to the upper side and the lower side, and the right side 51b is a hypotenuse. From the window 52, the light guide 30, the diffusion sheet 40, and the vertical prism sheet 50 are exposed in order from the left side 51a side. A part of the light guide 30 (light guide exposed portion) 30a exposed from the window 52 is rectangular. On the other hand, a lower end 40b of the part (first exposed portion) 40a of the diffusion sheet 40 exposed from the window 51a has a wave shape. A part (second exposed portion) 50a of the vertical prism sheet 51 exposed from the window portion 52 has a trapezoidal shape. As described above, since the shape of the first exposed portion 40a and the shape of the second exposed portion 50a are clearly different, the diffusion sheet 40 and the vertical prism sheet 50 can be easily recognized. Further, since the second exposed portion 50a covers a part of the diffusion sheet 40, when the diffusion sheet 40 is laminated on the vertical prism sheet 50, the second exposed portion 50a is covered with the diffusion sheet 40. The waveform of the lower end 40b is continuously displayed up to the right side 51b. Thereby, it can recognize easily that it laminated | stacked in the wrong order, and confirmation of a lamination | stacking order can be performed easily.

  In this embodiment, the ribs 38a to 38d are provided at the lower edge portion of the light guide 30, but instead of this, a rib protruding toward the ride guide 30 may be provided at the lower edge portion 95 of the TFT holder 90. In this case, the TFT holder and the light guide are joined via a buffer material (double-sided tape) between the rib of the TFT holder and the light guide. This also has the same effect as the backlight device 1.

  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 figure which shows the state after the assembly of the backlight apparatus. 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 front view (A) of the TFT holder 90, the bottom view (B) of the TFT 90 holder, and the back view (C) of the TFT holder 90. 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. FIG. 3 is a cross-sectional view (a) showing a state where the upper holder 60 and the printed board assembly 70 are attached to the light guide 30 at a position of line P-P in FIG. 2, and a cross-sectional view (b) showing a state where the TFT holder 90 is attached. Sectional drawing (c) which shows the state which mounted | wore the TFT holder 90 in the QQ line position of FIG. The top view (a) of the state which made the light guide 30 hold | maintain an optical sheet, the enlarged view (b) of A part, and sectional drawing (c) of the BB line position. The perspective view which represented typically the lamination | stacking order of the diffusion sheet 40, the vertical eye prism sheet 50, and the horizontal eye prism sheet 51. FIG. FIG. 6 is a front view of the vicinity of the left side of the lower end in a state where a diffusion sheet 40, a vertical prism sheet 50, and a horizontal prism sheet 51 are stacked.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Backlight apparatus 10 Shield case 11 Rib receiving seat 12 Upper holder receiving seat 13 Printed circuit board assembly receiving seat 14 Tongue piece 15 Left side holder accommodating part 15b Upper holder fixing hole 15c Locking claw 16 Right side holder accommodating part 16b For upper holder fixing Hole 16c Locking claw 20 Diffusion sheet 30 Light guide 31 Light incident area 32 Light guide front face 32a Light exit area 33 Light guide rear face 34 Holding rib 34a Holding rib outer face 35, 36 Stepped face 37a-j Pin 38a ~ D Rib 40 Diffusion sheets 41a, 41b, 41f, 41g, 41h Holes 41c, 41d, 41e, 42a, 42b Cut 50 Vertical prism sheet 51 Horizontal eye prism sheet 60 Upper holder 61 Opening 62 Holding part 62a Ceiling part of holding part 62b Inner wall surface 65 of holding part 1st narrow extension part 6 a, 66a, 67a the locking leg 66 second narrow extension portion 67 wide extending portion 67b positioning projections 70 a printed circuit board assembly 71 substrate 72 LED lamp 80 left holder 85 right holder 90 TFT holder 101 rib-shaped small projections

Claims (5)

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 face from the front, and
An optical sheet disposed on the front side of the light guide plate ;
A liquid crystal panel holding member disposed on the front side of the optical sheet, and a backlight device comprising:
The optical sheet has a notch,
The light guide plate and the holding member are joined via a cushioning material at a position corresponding to the notch portion of the optical sheet,
The light guide plate includes a rib at a position corresponding to the notch of the optical sheet,
The said buffer material is a backlight apparatus arrange | positioned between the said rib and the said liquid crystal panel holding member. The upper end surface of the light guide plate is a light incident surface,
The liquid crystal panel holding member has a frame shape,
The backlight device according to claim 1, wherein the notch is provided along a lower edge of the light guide plate. The backlight device according to claim 1, wherein the cushioning material is in contact with the entire front surface of the rib .   The backlight device according to claim 1, wherein the cushioning material is a double-sided tape.   The backlight device according to claim 1, wherein the buffer material has a thickness of about 0.050 to about 0.700 mm.

Images