JP4743104B2 - Backlight device and liquid crystal display device - Google Patents

Description

  The present invention relates to a backlight device using a light emitting diode (LED) as a light source and a transmissive liquid crystal display device equipped with the backlight device.

  2. Description of the Related Art Conventionally, in a transmissive LCD (Liquid Crystal Display) mounted on an electronic device such as a liquid crystal television or a PC (Personal Computer), a backlight is disposed on the back side of the LCD, and the backlight uses the LCD. The image is displayed by illuminating the back of the camera. Conventionally, CCFL (Cold Cathode Fluorescent Lighting) has been used as the light source of the backlight, but in recent years, LEDs have been promising as a light source that replaces the CCFL. By using an LED, high efficiency and a high color gamut can be achieved, and since no mercury is used unlike CCFL, adverse effects on the environment can be lost.

In a backlight device using a CCFL, a reflection plate that reflects light emitted from the CCFL is provided below the CCFL, and light is repeatedly reflected between a diffusion plate provided to face the reflection plate. Supplying to LCD panels. On the other hand, in a backlight device using LEDs, a wiring board provided so that a plurality of LEDs protrudes is fixed to the back chassis side of the backlight device, so the shape and number of each LED on the reflecting plate A combined opening is provided, and a reflective plate is provided so as to cover the wiring board while exposing each LED from the opening. A backlight device employing such a configuration is disclosed in, for example, Patent Document 1 below.
Japanese Patent Laying-Open No. 2005-352427 (FIGS. 2, 7, etc.)

  By the way, on the wiring board of the backlight device of Patent Document 1 above, in addition to the LED, a connector for inputting / outputting a signal for turning on the LED, and a screw for fixing the wiring board to the back chassis side Are also provided so as to protrude from the wiring board. And as above-mentioned, although a reflector is provided so that LED may penetrate and be exposed from the opening of a reflector, since the LED has a certain height, the said connector and screw are reflectors. It is located below the reflector without interfering with.

  However, in recent years, there has been a high demand for thinning liquid crystal display devices, and in order to reduce the thickness of a backlight device, when a low-profile LED is used, the reflector is provided closer to the surface of the wiring board. Therefore, the reflection plate interferes with the connector and the screw. Therefore, it is necessary to provide the reflector with an opening for exposing the connector and the screw, similarly to the opening for exposing the LED. However, if this opening is provided, there will be a clearance between this opening and the connector or screw. Therefore, if light enters this clearance or light is exposed to the exposed connector or screw itself, the wiring board The light is absorbed by the connector and the screw, and the light is lost. As a result, the luminance of the backlight device is reduced and the luminance is uneven.

  In view of the circumstances as described above, an object of the present invention is to provide a backlight device and a liquid crystal display device capable of preventing loss of light of an LED while achieving a reduction in thickness.

  In order to solve the above-described problems, a backlight device according to a main aspect of the present invention is provided so that a plurality of light emitting diodes and a connector for inputting or outputting a signal for lighting each light emitting diode are projected. A plurality of wiring boards provided, a first opening for covering each of the wiring boards, and exposing each of the light emitting diodes in the protruding direction; and a first opening for exposing the connector in the protruding direction. 2 on the surface, and a reflection plate capable of reflecting the light emitted from each of the light emitting diodes, and provided so as to face the reflection plate, and a part of the light is reflected to the reflection plate side. And a cover that is provided so as to cover at least a part of the second opening of the reflector, and a diffuser that transmits and diffuses the other part of the light and emits the light. Comprising a.

  This backlight device is mounted on, for example, a liquid crystal display device having a liquid crystal panel. In this liquid crystal display device, the light emitted from the light emitting diode is mixed while being repeatedly reflected between the reflection plate and the diffusion plate, and supplied to the liquid crystal panel side. According to the configuration of the backlight device of the present invention, it is possible to reduce the thickness of the backlight device by providing not only the light emitting diode but also the connector so as to be exposed from the reflecting plate. By covering the opening, light can be reflected by the covering portion. That is, it is possible to prevent the light from being incident on the connector exposed from the second opening or the clearance generated between the connector and the second opening in the surface direction of the reflection plate and losing the light. As a result, it is possible to prevent a decrease in luminance of the backlight device and occurrence of local luminance unevenness.

  In the backlight device, the covering portion may be a sheet material attached to the reflecting plate so as to cover the second opening.

  Thereby, the light emitted from the light emitting diode can be reflected by the sheet material only by sticking the sheet material to the second opening, and the loss can be easily prevented. As this sheet material, a material having a reflectance equivalent to that of the reflector can be used.

  In the backlight device, the covering portion cuts a portion of the reflecting plate facing the connector so as to form the second opening, and bends the cut portion so as to float in the protruding direction. It may be a flap part formed by.

  Thereby, since the emitted light of a light emitting diode can be reflected by a flap part, the loss of emitted light can be prevented, without providing a new member in a reflecting plate.

  In this case, the connector may have a highly light reflective material on its exposed surface.

Thereby, even if the emitted light from the light emitting diode is incident on the surface of the connector through the clearance between the flap portion and the second opening, the light can be reflected by the highly light reflective material on the surface. Therefore, the loss of light can be prevented with a higher probability. The high light reflective material is, for example, a highly reflective metal such as aluminum or silver, an inorganic material such as fine titanium oxide (TiO ₂ ) or barium titanate (BaTiO ₃ ), and a myriad of materials for light scattering. Organic materials such as fine porous acrylic and polycarbonate having holes.

  In this case, the flap portion may have a flat portion substantially parallel to the surface of the reflecting plate.

  Accordingly, the clearance between the second opening and the flap portion can be reduced as compared with the case where the flap portion has only a surface inclined with respect to the surface of the reflection plate, and the reflection plate from the diffusion plate side. Since the light reflected to the side can be more reliably reflected to the diffuser side by the plane portion, the loss of light can be prevented with a higher probability.

  In the backlight device, the covering portion may be a highly light-reflective material that the exposed surface of the connector has.

  Thereby, the loss of light can be prevented without providing a new member on the locking member reflector. The high light reflective material is, for example, painted on the surface, but the connector itself may be made of a high light reflective material.

  In the backlight device, the covering portion may be a convex portion that is formed integrally with the second opening by causing a portion of the reflecting plate facing the connector to protrude in the protruding direction.

  Thus, by forming the concave portion integrally with the reflection plate, it is possible to prevent light loss without providing a new member on the reflection plate while protruding the connector from the surface of the reflection plate.

  A backlight device according to another aspect of the present invention includes a plurality of wiring boards provided so that a plurality of light emitting diodes protrude, a holding member that holds each of the wiring boards, and each of the wiring boards that holds the holding member. A locking member provided so as to protrude at least partially from each wiring board, and provided so as to cover each wiring board, and exposing each light emitting diode in the protruding direction. A reflection plate that has a first opening for exposing and a second opening for exposing the locking member in the protruding direction on the surface, and is capable of reflecting light emitted from each of the light emitting diodes; A diffusing plate that is provided to face the reflecting plate, reflects a part of the light to the reflecting plate side, transmits the other part of the light to be diffused, and emits the second light of the reflecting plate; At least part of the opening Provided so as to cover, comprising a reflective capable covering portion the light.

  Here, the locking member is, for example, a screw, a screw, a pin, or the like. With this configuration, by providing not only the light emitting diode but also the locking member so as to be exposed from the reflecting plate, the backlight device can be thinned, and the second opening is covered by the covering portion. The light can be reflected by the covering portion to prevent light loss.

  In the backlight device, the covering portion may be a sheet material attached to the reflecting plate so as to cover the second opening.

  Thereby, the light emitted from the light emitting diode can be reflected by the sheet material only by sticking the sheet material to the second opening, and the loss can be easily prevented.

  In the backlight device, the covering portion may be a highly light-reflective material that the exposed surface of the locking member has.

  Thereby, the loss of light can be prevented without providing a new member on the locking member reflector. The high light reflective material is, for example, coated on the surface, but the locking member itself may be made of a high light reflective material.

  In the backlight device, the covering portion may be a convex portion formed integrally with the second opening by causing a portion of the reflecting plate facing the locking member to protrude in the protruding direction. I do not care.

  Thus, by forming the concave portion integrally with the reflecting plate, it is possible to prevent light loss without providing a new member on the reflecting plate while protruding the locking member from the surface of the reflecting plate.

  A liquid crystal display device according to another aspect of the present invention includes a plurality of wiring boards provided so that a plurality of light emitting diodes and a connector for inputting or outputting a signal for lighting each of the light emitting diodes protrude. A first opening for covering each of the wiring boards, and exposing each of the light emitting diodes in the protruding direction, and a second opening for exposing the connector in the protruding direction. A reflecting plate capable of reflecting the light emitted from each of the light emitting diodes, and provided to face the reflecting plate, and reflects a part of the light to the reflecting plate side, and A backlight device having a diffusing plate that transmits and diffuses a portion, and a covering portion that is provided so as to cover at least a part of the second opening of the reflecting plate and reflects the light; Varying the transmittance of light emitted from the diffusion plate and a display liquid crystal panel capable of video in.

  A liquid crystal display device according to still another aspect of the present invention includes a plurality of wiring boards provided so that a plurality of light emitting diodes protrude, a holding member that holds the wiring boards, and the holding of the wiring boards. A locking member that can be locked to a member, and is provided so as to cover at least a part of each wiring board and to cover each wiring board, and exposes each light emitting diode in the protruding direction. A reflector having a first opening for causing the second locking member and a second opening for exposing the locking member in the protruding direction on the surface, and capable of reflecting light emitted from each of the light emitting diodes; A diffusing plate that is provided to face the reflecting plate, reflects a part of the light to the reflecting plate side, transmits the other part of the light and diffuses it, and emits the second light; and the second of the reflecting plate At least part of the opening Provided so as to cover, it includes a backlight device and a possible covering portion reflecting the light, and a liquid crystal panel capable of displaying an image by changing the transmittance of light emitted from the diffuser.

  As described above, according to the present invention, it is possible to provide a backlight device and a liquid crystal display device capable of preventing the loss of light of an LED while achieving a reduction in thickness.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, a first embodiment of the present invention will be described. FIG. 1 is a schematic exploded perspective view of a liquid crystal display device having a backlight device according to the present embodiment, and FIG. 2 is a partial cross-sectional view in the Z direction of the liquid crystal display device of FIG. FIG. 3 is a partially cutaway plan view showing the configuration of the backlight device of the liquid crystal display device shown in FIGS. 1 and 2.

  This liquid crystal display device is used for a display panel of a television receiver having a large display screen of, for example, 40 inches or more, and is a transmission type that displays an image by illuminating the liquid crystal panel from the back side with a backlight device. Liquid crystal display device.

  As shown in both figures, the liquid crystal display device 100 sandwiches the liquid crystal panel 2, the middle frame 3, the optical sheet laminate 4, the diffusion plate 5, the reflection plate 6, and the light source array 7 between the front chassis 1 and the back chassis 8. It is comprised by holding in. The front chassis 1, the middle frame 3, and the back chassis 8 are made of metal such as aluminum. These may be made of resin, but since the liquid crystal panel 2 of the liquid crystal display device 100 is large, considering the strength and the difference in coefficient of thermal expansion, metallicity is preferable. The optical sheet laminate 4, the diffusion plate 5, the reflection plate 6, the light source array 7, and the back chassis 8 form a backlight device 10 and supply display light from the back side of the liquid crystal panel 2.

  As shown in FIG. 2, the outer peripheral edge of the liquid crystal panel 2 is supported between the lower surface of the front chassis 1 and the upper surface 3 a of the middle frame 3 via, for example, a spacer 11 and a guide member 12. Although not described in detail, the liquid crystal panel 2 encloses a liquid crystal between the first glass substrate and the second glass substrate and applies a voltage to the liquid crystal to change the direction of the liquid crystal molecules to thereby transmit the light transmittance. To change. A striped transparent electrode, an insulating film, and an alignment film are formed on the inner surface of the first glass substrate, and light, three primary colors of red, green, and blue (RGB) are formed on the inner surface of the second glass substrate. The color filter, the overcoat layer, the striped transparent electrode, and the alignment film are formed. A polarizing film and a retardation film are bonded to the surfaces of both glass substrates.

  In the liquid crystal panel 2, an alignment film made of polyimide is arranged in the horizontal direction (both X and Y directions) with the liquid crystal molecules as an interface, and the polarizing film and the retardation film have achromatic wavelength characteristics and are white. The image is displayed in color by achieving full color using a color filter. In addition, the liquid crystal panel 2 is not limited to such a configuration, and a liquid crystal panel having various existing configurations can be applied.

  As shown in FIGS. 1 and 2, a rectangular opening 41 is formed in the upper surface 3 a of the middle frame 3, and a rectangular opening 42 is also formed in the lower surface 3 b of the middle frame 3. The area of the opening 42 is formed larger than the area of the opening 41.

  The optical sheet laminate 4 and the diffusion plate 5 are supported so as to be sandwiched between the lower surface 3b of the middle frame 3 and the bracket member 15 attached to the back chassis 8 in a state where the optical sheet laminate 4 and the diffusion plate 5 are laminated. For example, a spacer 11 is interposed between the middle frame 3 and the optical sheet laminate 4. Further, between the bracket member 15 and the diffusing plate 5, an edge portion 6c of the reflecting plate 6 to be described later is inserted.

  Although details are omitted for the optical sheet laminate 4, for example, a polarization conversion sheet for decomposing display light emitted from the light source array 7 side and supplied to the liquid crystal panel 2 into orthogonal polarization components, or a phase difference between light waves. A plurality of retardation films (films) for compensating for wide-angle viewing angle and preventing coloring, and a plurality of optical functions such as a diffusion sheet and a prism sheet for diffusing display light to achieve uniform brightness An optical function sheet is laminated.

  The diffusion plate 5 reflects a part of the display light incident from one main surface side (the light source array 7 side) to the light source array 7 side, and transmits a part of the display light to be refracted and reflected inside. By making it diffuse, it is made to enter into the optical sheet laminated body 4 in a uniform state from the other main surface side over the entire surface.

  By the way, in the liquid crystal display device 100, when an observer observes a peripheral part from the center of the liquid crystal panel 2 from an oblique angle (for example, 45 degrees), it is necessary to prevent the peripheral image from becoming dark. . The necessity increases as the display screen becomes larger as in the liquid crystal display device 100 of the present embodiment. Therefore, the middle frame 3 is provided with a step portion 13 so that the inner surface connecting the opening 41 of the upper surface 3a and the opening 42 of the lower surface 3b expands toward the back along the observation angle of the observer. Therefore, no matter what angle the observer observes the liquid crystal panel 2, the illumination light of the backlight device 10 is obtained so that the image can be observed.

  The step portion 13 includes a plane portion 13a substantially parallel to the main surface of the liquid crystal panel 2, a side surface portion 13b connecting the plane portion 13a and the opening 41 of the upper surface 3a, and an opening 42 of the plane portion 13a and the lower surface 3b. It is comprised by the side part 13c which connects. However, when light emitted from the backlight device 10 via the diffuser plate 5 and the optical sheet laminate 4 is reflected on the flat surface portion 13a, the reflected light strikes the optical sheet laminate 4 to cause halation (middle frame 3). Frame-like reflection along the shape) may occur.

  For example, as shown in FIG. 2, when the observer observes the peripheral portion of the liquid crystal panel 2 at the observation angle a, since the observation is from a direction perpendicular to the main surface of the liquid crystal panel 2, as described above. Such halation cannot be visually recognized by the observer, but when the observer observes the peripheral portion of the liquid crystal panel 2 from an oblique angle as in the observation angle b, the halation is visually recognized by the observer. Such halation will cause an unnatural image to appear, degrading the quality of the liquid crystal display device 100.

  Therefore, in the present embodiment, the matte black tape 14 is affixed to the flat surface portion 13a. As a result, the light incident on the stepped portion 13 side from the optical sheet laminate 4 is absorbed by the black tape 14 and does not strike the optical sheet laminate 4, thereby providing a high-quality liquid crystal display device 100 without halation. be able to.

  Instead of applying the black tape 14, the stepped portion 13 or the tapered portion 63 of the middle frame 3 may be painted black. When the middle frame 3 is made of aluminum as in the present embodiment, it is preferable to perform black alumite processing. Further, in the present embodiment, the middle frame 3 is made of metal (made of aluminum) in consideration of the influence of the strength and the difference in thermal expansion coefficient when the liquid crystal display device 100 is enlarged, but these influences are solved. If possible, the middle frame 3 itself may be formed of black resin.

  As shown in FIG. 3, the light source array 7 has a long shape extending in the horizontal direction (X direction in FIG. 3), and a plurality of rows are arranged on the bottom surface of the back chassis 8 at predetermined intervals along the Y direction in FIG. Are lined up. In this embodiment, twelve light source arrays 7 are provided, but the number is not limited to this number. 3 shows a state in which the middle frame 3, the optical sheet laminate 4, and the diffusion plate 5 are excluded from the backlight device 10.

  As shown in FIGS. 2 and 3, each light source array 7 includes a metal array base 16 and a plurality of light source devices 20 arranged in the recess 16 a of the array base 16. The number of light source devices 20 arranged in one array base 16 is four, for example, but is not limited to this number. The light source array 20 is fixed to the bottom surface of the back chassis 8 by screwing the light source device 20 with the array base 16 and the back chassis 8, for example.

  Each light source device 20 includes a wiring board 22, a plurality of LED units 25 mounted on the wiring board 22, an input connector 18 for inputting a signal for lighting each LED 21 of the LED unit 25, and the signal thereof. The output connector 19 for performing the output is provided. As a material for the wiring board 22, for example, a resin such as a glass epoxy resin is used instead of a metal such as aluminum for cost reduction.

  4 is an enlarged view of a portion of the backlight device 10 surrounded by a broken line A in FIG. As shown in FIG. 3 and FIG. 3, each LED unit 25 is configured such that a plurality of LEDs 21 are close to each other in a non-linear shape (cross shape) as a unit, and one light source device 20 includes a plurality of LED units 25. Provided. Each LED 21 of each LED unit 25 is provided so as to protrude from the surface of the wiring board 22 in the Z direction. Specifically, for example, one LED unit 25 is formed by arranging a red LED 21a and a blue LED 21b each provided in the X direction and two green LEDs 21c and 21d provided in the Y direction in a cross shape. Composed. However, the left end and right end LED units 25 are arranged not in a cross shape in the XY direction but in an oblique direction, and the left and right LED units 25 are symmetrically arranged. The LED units 25 are arranged, for example, 6 units at a predetermined interval (for example, 60 mm) in the longitudinal direction (X direction) on the wiring board 22 of one light source device 20. Accordingly, in the backlight device 10 of the present embodiment, 6 × 4 × 12 = 288 units of LED units 25 are provided, and 4 × 288 = 1152 LEDs 21 are provided. Note that the numbers and arrangement intervals of the LED units 25 and the LEDs 21 are not limited to those described or illustrated above, and can be appropriately changed depending on the size of the liquid crystal panel 2, the light emission capability of the LEDs 21, and the like.

  FIG. 5 is a cross-sectional view taken along the line AA ′ of the backlight device 10 shown in FIG. As shown in the figure, each LED 21 includes a light-emitting element (not shown) and a light-emitting element holding base 27 that holds the light-emitting element inside, a resin holder 24 that is connected to the light-emitting element, and a resin holder 24 that is connected to the light-emitting element. Lead wire 26 drawn out from. Each LED 21 is a so-called side emission type LED having directivity for emitting the main component of the emitted light in the outer peripheral direction of the light emitting element.

  The wiring board 22 of each light source device 20 is made of a resin material such as glass epoxy resin (FR4). By making the wiring board 22 made of resin, the cost can be reduced as compared with the case where it is made of metal such as aluminum as in the prior art. Each wiring board 22 is formed with a wiring pattern for connecting the LEDs 21 of the respective colors of the LED units 25 in series, lands (not shown) for connecting the terminals of the LEDs 21, and the like. In addition, a solder pad 28 made of a metal such as copper is formed on the wiring board 22 in order to solder the light emitting element holding base 27 and the lead wire 26 of each LED 21. The solder pad 28 electrically connects the light emitting element and the lead wire of the LED 21 to the wiring pattern on the wiring board 22.

  The wiring board 22 is provided with a thermal via 52 that penetrates the wiring board 22 in the Z direction from a solder pad 28 soldered to the light emitting element holding base 27 of each LED 21. The thermal via 52 is provided with a metal plating layer 53 such as copper or silver. The metal plating layer 53 is also formed over the lower surface of the wiring board 22. With this thermal via 52, even when the wiring board 22 is made of a resin having low thermal conductivity, the heat generated from each LED is conducted to the array base 16 and radiated through the back chassis 8 or the surrounding air. Is possible.

  A plate-like adhesive material 23 is provided between the wiring board 22 and the array base 16. The adhesive material 23 is made of a material having high thermal conductivity based on, for example, an acrylic or rubber adhesive material, and both surfaces thereof are adhesive. By pressing the wiring board 22 to the array base 16 side through the adhesive material 23 with a specified load, the two are easily closely fixed over the entire surface. Thereby, the heat generated from the LEDs 21 can be uniformly conducted to the array base 16 uniformly and can be efficiently radiated, and the temperature difference between the LEDs 21 can be reduced.

  The adhesive material 23 is made of an insulating material. As described above, the thermal via 52 has the metal plating layer 53, and the metal plating layer 53 functions not only as a heat conductor but also as a conductor. However, by using the adhesive material 23 as an insulator, the thermal via 52 (LED 21) and the array base 16 can be reliably insulated and the reliability can be improved.

  As shown in FIG. 4, each wiring board 22 is arrayed via an adhesive material 23 at a substantially central portion in the longitudinal direction (X direction) and one end side in the short direction (Y direction) of each wiring board 22. One screw 32 for locking to the base 16 is provided. Thereby, the holding force of the wiring board 22 by the adhesive material 23 can be reinforced, and the wiring board 22 can be prevented from dropping from the array base 16 by any chance. The screw 32 is only for the purpose of preventing the wiring board 22 from falling off, and is not intended for tightly fixing the wiring board 22 to the array base 16. Therefore, it is not necessary to tighten and press the wiring board 22 to the array base 16 side with the screws 32, and only one place is sufficient. Therefore, an increase in man-hours and costs due to the provision of the screws 32 can be minimized.

As shown in FIGS. 2 and 5, a white solder resist 61 is applied to the surface of each wiring board 22. The white solder resist 61 includes a highly light reflective material that reflects light efficiently. Examples of the highly light-reflective material include inorganic materials such as fine titanium oxide (TiO ₂ ) and barium titanate (BaTiO ₃ ), and organic materials such as fine and high-quality acrylic having numerous holes for light scattering and polycarbonate. A material etc. are used suitably.

  Conventional wiring boards are generally coated with a solder resist such as green, yellow, and black. However, as described above, the diameter d2 of each opening 6d provided in the reflecting plate 6 is formed to be slightly larger than the diameter d1 of each LED 21, so that the solder resist of the wiring board is made green or yellow and In the case of black or the like, if light enters the clearance 71 between each LED 21 and each opening 6d, the light is absorbed by the solder resist portion, and as a result, the light from the LED 21 is lost. It will be.

  Therefore, in this embodiment, by applying a white solder resist 61 containing a highly light-reflective material to the wiring board 22, the light emitted from the LED 21 and reflected from the diffusion plate 5 to the reflection plate 6 side or the reflection plate 6 is used. Even if the light reflected and reflected again from the diffusion plate 5 to the reflection plate 6 side enters the clearance 71 between the LED 21 and the opening 6d, the white solder resist 61 reflects the light to the diffusion plate 5 side. I have to. Thereby, luminance unevenness due to light loss can be minimized.

  As shown in FIGS. 3 and 4, an input connector 18 is mounted on each wiring board 22 at one end in the short direction (Y direction) and at one end in the long direction (X direction). In addition, an output connector 19 is mounted on the other end.

  In addition, as described above, each light source array 7 is formed by arranging the wiring boards 22 in the same direction on each array base 16 in each light source device 20. Of the light source arrays 7, the first row, the third row, the fifth row,..., The light source array 7 in the odd-numbered row of the eleventh row, each wiring board 22 has an input connector 18. The light source devices 20 are arranged so that one side portion on which the output connector 19 is mounted faces downward. On the other hand, in the light source array 7 in the second column, the fourth column, the sixth column,..., The even column of the twelfth column, each wiring board 22 has an input connector 18 and an output connector 19 respectively. The light source devices 20 are arranged so that the mounted one side is upward.

  That is, each light source array 7 is provided so that one light source device 20 and another light source device 20 adjacent to the light source device 20 in the Y direction are inverted by 180 degrees on the XY plane. Accordingly, the input connector 18 of one light source device 20 and the output connector of another light source device 20 adjacent thereto in the Y direction face each other, and the output connector 19 of one light source device 20 and the other light source device 20 The input connector 18 is opposed to the input connector 18. Thereby, the shortest wiring can be performed between the light source devices 20 in different columns.

  Further, as shown in FIG. 4, the two green LEDs 21c (G1) and 21d (G2) of each light source device 20 are different in chromaticity from each other, and the average chromaticity of the two becomes a predetermined chromaticity. Has been. That is, as long as the average chromaticity becomes a predetermined chromaticity, green LEDs having any chromaticity can be combined. By comprising in this way, the dispersion | variation in especially large green LED can be absorbed among each color LED.

  The green LEDs 21c and 21d (G1 and G2) are arranged in a zigzag shape along the X direction. That is, in each LED unit 25, the green LEDs 21c and 21d are alternately switched as the vertical position goes in the X direction.

  As described above, in the backlight device 10, each light source device 20 adjacent in the Y direction is arranged by being inverted 180 degrees, and therefore, the green LEDs 21 c and 21 d having different chromaticities are temporarily arranged along the X direction. When arranged in a straight line, the green LEDs 21c and 21d (G1 and G2) having the same chromaticity are close to each other between the light source devices 20 adjacent in the Y direction, thereby causing uneven color and uneven brightness. It will occur. However, by arranging the green LEDs 21c and 21d in a zigzag manner as in the present embodiment, the distances between G1 and G2 are uniformly arranged between the light source devices 20 adjacent in the Y direction. Therefore, occurrence of uneven color and uneven brightness can be suppressed.

  The green LEDs 21c and 21d may have different luminance as well as chromaticity. In this case, green LEDs having any luminance can be combined as long as the average luminance of the green LEDs 21c and 21d becomes a predetermined luminance.

  In addition to the green LEDs 21c and 21d, a plurality of red LEDs 21a or blue LEDs 21b are mounted on the LED unit 25, and the average chromaticity (or average chromaticity) of the plurality of red LEDs 21a or blue LEDs 21b is a predetermined chromaticity ( (Or brightness).

  As shown in FIGS. 2 to 5, a reflector 6 is provided above each light source array 7 (in the Z direction) so as to cover all the light source arrays 7. The reflecting plate 6 is formed by bonding a reflecting material made of foaming PET (Polyethylene terephthalate) containing a fluorescent material on the surface of an aluminum plate or a stainless steel plate, for example. Of the light emitted from each LED unit 25 of the light source device 20, the light reflected by the diffusion plate 5 is reflected by the reflection plate 6 and enters the diffusion plate 5 again. By repeatedly reflecting the emitted light from the LEDs 21 of each color between the diffuser plate 5 and the reflector plate 6, the reflectance and color mixing properties are improved by the principle of increased reflection.

  As shown in FIG. 2, the reflecting plate 6 includes a flat portion 6a, an edge portion 6c formed on the periphery of the reflecting plate 6 substantially in parallel with the flat portion 6a, and between the flat portion 6a and the edge portion 6c ( And an inclined portion 6b formed from the diffusion plate 5 side to the light source device 20 side around the flat surface portion 6a. The flat surface portion 6a is provided with a plurality (1152) of circular openings 6d according to the number and shape of each LED of each LED unit 25, and the reflecting plate 6 allows each LED 21 to pass through the opening 6d. In this manner, the flat portion 6a is provided on the upper surface of the array base 16 of each light source array 7 so as to be fixed by, for example, adhesion.

  As shown in FIG. 4, each opening 6 d is formed so that its diameter d <b> 2 (and outer peripheral length) is slightly larger than the diameter d <b> 1 (and outer peripheral length) in the XY plane of each resin holder of each LED 21. As a result, a clearance 71 is formed between each LED 21 and each opening 6d. Therefore, by absorbing the dimensional tolerance of each LED 21 and variations such as mounting accuracy when each LED 21 is mounted on each wiring board 22, The reflector 6 can be easily assembled. Further, as described above, only one reflector 6 is provided so as to cover all the light source devices 20 and is provided with a flexible material such as aluminum. Although it may be considered that the position is displaced between the respective openings 6d and the respective LEDs 21, the reflector 71 can be easily assembled by the clearance 71 in response to the bending. The width c of the clearance 71 on the XY plane is, for example, about 1 mm to 2 mm, but is not limited to this.

  Further, as described above, the reflection plate 6 is held by inserting the edge portion 6 c between the diffusion plate 5 and the bracket member 15 provided in the back chassis 8. Further, the reflecting plate 6 is also held by an optical stud 17 described later.

  As shown in FIGS. 2 to 4, a plurality of optical studs 17 are provided between the diffusion plate 5 and the reflection plate 6. As shown in FIG. 2, the optical stud 17 is composed of a protrusion 17a, a base portion 17c, and a shaft portion 17b that connects them, for example, a fitting hole (see FIG. 2) provided in the recess 8b of the back chassis 8 and the reflection plate 6. (Not shown) is penetrated by the shaft portion 17b, and the concave portion 8b and the reflection plate 6 are fixed so as to sandwich the projection portion 17a and the base portion 17c. The optical stud 17 is integrally formed of a milky white synthetic resin material having light guiding properties, mechanical rigidity, and a certain degree of elasticity, such as polycarbonate resin. By providing the optical stud 17, the bottom surface of the diffusion plate 5 is held so as to abut against the tip of the projection 17 a of the optical stud 17, and the distance and parallelism between the diffusion plate 5 and the reflection plate 6 are maintained. Further, the occurrence of uneven color due to the deflection of the diffusion plate 5 and the reflection plate 6 is prevented.

  As shown in FIG. 3, a plurality of optical studs 17 are provided over the entire surface of the backlight device 10. For example, three or four optical studs 17 are provided at predetermined intervals in the Y direction every time the LED units 25 for three rows are provided, and at the central portion of the backlight device 10, predetermined intervals are provided in the Y direction. Five are provided, and a total of 27 backlight devices 10 are provided. Of course, this number can be changed as appropriate. Further, as shown in FIGS. 3 and 4, the optical stud 17 is provided at a position that is substantially the same distance from the four LED units 25 adjacent to each other. If the optical stud 17 is provided at an intermediate position between two LED units 25 adjacent in the X direction or the Y direction, the optical stud 17 prevents the color mixture of the emitted lights between the two LED units 25. Color unevenness or luminance unevenness due to any of red, blue, and green colors occurs. However, in the present embodiment, by providing the optical stud 17 at substantially the center of the four LED units 25 as described above, it is possible to provide a high-quality liquid crystal display device that suppresses the occurrence of color unevenness and luminance unevenness. Can do.

  6 is a sectional view of the vicinity of the connector 18 of the wiring board 22 shown in FIG. As described above, the reflecting plate 6 is provided so as to penetrate the LED 21 from the opening 6d and be exposed on the surface of the reflecting plate 6, but this LED 21 is used to reduce the thickness of the backlight device 10. Since a relatively low height is used, the input connector 18 and output connector 19 mounted on the wiring board 22 and the reflector 6 interfere with each other in the Z direction in the same manner as the LED 21. Become. Therefore, in the present embodiment, as shown in FIGS. 4 and 6, an opening 6 e for penetrating the input connector 18 and the output connector 19 through the reflection plate 6 and exposing it to the surface of the reflection plate 6 is also provided. Forming.

  The opening 6e is formed to be slightly larger than the area on the XY plane of the input connector 18 and the output connector 19 in consideration of the mounting accuracy of the input connector 18 and the output connector 19. Further, the input connector 18 and the output connector 19 are also provided with lead wires 43 for connecting them, and the opening 6e is formed in consideration of interference of the lead wires 43. Therefore, a clearance 33 exists between the opening 6 e and the input connector 18 and the output connector 19.

  However, if the light emitted from the LED 21 enters the clearance 33 or hits the input connector 18, the output connector 19, or the lead wire 43, the light is lost without being reflected to the diffusion plate 5 side. As a result, the brightness of the backlight device 10 is reduced, and local brightness unevenness occurs.

  Therefore, in the present embodiment, as shown in FIGS. 3, 4 and 6, the reflection plate 6 is covered with the reflection sheet so as to cover the input connector 18 and the output connector 19 exposed from the opening 6 e of the reflection plate 6. 31 is affixed. The reflective sheet 31 is made of a reflective material such as foamable PET, as with the reflective plate 6. As a result, even when it is necessary to provide the reflector 6 with the openings 6e for the input connector 18 and the output connector 19, the loss of light is eliminated, the light extraction efficiency is improved, and the luminance unevenness is small. The backlight device 10 can be provided.

  The inventors measured the effect of improving the luminance of the backlight device 10 when the reflecting sheet 31 was provided on the reflecting plate 6 using a planar luminance measuring device. FIG. 7 is a diagram showing the measurement results. FIG. 9A shows the results of measuring the luminance of the backlight device 10 when the reflective sheet 31 is not provided, and FIG.

  As shown in FIG. 5A, when the reflecting sheet 31 is not provided on the reflecting plate 6, there is a loss of light in the opening 6e, and therefore the portion of the reflecting plate 6 where the opening 6e is concentrated (in the X direction). In the vicinity of the boundary between the wiring boards 22), a luminance drop occurs and luminance unevenness occurs. In addition, the luminance near the center of the backlight device 10 is lower than the surrounding area.

On the other hand, as shown in FIG. 5B, by providing the reflection sheet 31 in the opening 6e, the luminance drop and luminance unevenness as shown in FIG. 5A are improved, and the luminance near the center is not reduced. . In this measurement, the central luminance was 5899 cd / m ^{2 in} the case of (a) in the figure, whereas it was 6005 cd / m ^{2 in} the case of (b), an improvement of about 1.8%. It was seen. In addition, in the case of FIG. 10A, the average luminance was 5094 cd / m ² , whereas in the case of FIG. 5B, it was 5155 cd / m ² , showing an improvement of about 1.2%. It was. In addition, no other significant changes in characteristics were observed between FIGS.

  As described above, in the present embodiment, the distance between the reflecting plate 6 and the wiring board 22 is made as small as possible to realize the thinning of the backlight device 10, but the reflecting sheet 31 covers the opening 6 e of the reflecting plate 6. By providing, loss of light in the opening 6e can be prevented, and luminance reduction and luminance unevenness of the backlight device 10 can be prevented.

  In addition to the input connector 18 and the output connector 19, the screws 32 for locking the wiring substrate 22 to the array base 16 as described above are provided on the wiring substrate 22 as shown in FIG. The head of the screw 32 exposed on the wiring board 22 also has a height that interferes with the reflector 6. For this reason, the reflector 6 is also provided with an opening 6f for allowing the head of the screw 32 to penetrate and be exposed. A reflective sheet (not shown) similar to the reflective sheet 31 provided in the opening 6e may be attached to the opening 6f so as to cover the screw 32. Thereby, the loss of light can be further prevented.

  By the way, when the LED unit 25 is employed as the light source of the backlight device 10 as in the present embodiment, if the LED unit 25 is continuously turned on, the temperature of the back chassis 8 of the light source device 20 and the like with time elapses. The temperature rises by about 30 ° C relative to room temperature. Along with this, the temperature of the liquid crystal panel 2 also rises, for example, by about 20 ° C. with respect to room temperature via the front chassis 1, the middle frame 3, and the like. As a result, a temperature difference is generated between the peripheral portion of the liquid crystal panel 2 held by the front chassis 1 and the middle frame 3 and the central portion of the liquid crystal panel 2 away from the peripheral portion. As a result, a stress is generated in the glass substrate in which the liquid crystal is sealed, the refractive index of the glass substrate changes, and a phenomenon in which the polarization characteristics change occurs. In particular, on a black screen, the polarization characteristic changes in the direction in which it appears white, which results in uneven brightness.

  Therefore, in the present embodiment, as shown in FIG. 3, for example, isosceles triangular black sheets 51 are attached to the four corners of the flat portion 6 a of the reflecting plate 6 to reduce the reflectance at the four corners of the reflecting plate 6, Improves brightness unevenness. The shape of the black sheet 51 is not limited to an isosceles triangle shape, and may be another shape such as an L shape. Further, the black sheets 51 may be provided at the four corners of the inclined portion 6b instead of the four corners of the flat surface portion 6a of the reflecting plate 6. Further, instead of applying the black tape 51, a black coating or black printing process may be performed. That is, a process for reducing the reflectivity at the four corners of the reflecting plate 6 may be performed.

  Next, the drive circuit of the liquid crystal display device 100 will be briefly described. FIG. 8 is a block diagram showing the drive circuit.

  As shown in the figure, the liquid crystal display device 100 is provided with respect to the liquid crystal panel 2 for displaying an image, the backlight device 10 disposed on the back side of the liquid crystal panel 2, the backlight device 10 and the liquid crystal panel 2. A control unit 40 for performing various controls and a memory 36 accessible by the control unit 40 are provided. The control unit 40 includes a video signal detection circuit 39 that detects a video signal, a backlight lighting control circuit 35 that controls lighting of the backlight device 10, and a liquid crystal panel control circuit 34 that controls driving of the liquid crystal panel 2. ing.

  The liquid crystal panel 2 has a source driver 37 and a gate driver 38 for sending drive signals to the liquid crystal panel 2. Further, as described above, the liquid crystal panel 2 is provided with color filters of three primary colors (RGB) (not shown), and one pixel is composed of three sub-pixels corresponding to RGB. The configuration of the color filter may be a configuration of four or more primary colors including colors other than RGB, for example, colors such as emerald or cyan.

  The video signal detected by the video signal detection circuit 39 is supplied to the source driver 37 and the gate driver 38 by the liquid crystal panel control circuit 34 via the memory 36 at a predetermined timing, and the liquid crystal panel 2 is driven by the control of both drivers. The video is displayed. On the other hand, the backlight lighting control circuit 35 generates a backlight lighting signal and drives each LED 21 of each light source device 20 of the backlight device 10.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the present embodiment and subsequent embodiments, portions having the same configuration and function as those of the first embodiment described above are denoted by the same reference numerals, and description and illustration thereof are omitted or simplified.

  FIG. 9 is a partial plan view of the backlight device 10 according to the present embodiment, and FIG. 10 is a partial cross-sectional view of the vicinity of the input connector 18 of the wiring board 22 shown in FIG.

In the above-described embodiment, the reflective sheet 31 is attached to the opening 6 e of the reflective plate 6. Instead, in the present embodiment, as shown in FIGS. 9 and 10, first, the clearance 33, particularly between the main body of the input connector 18 and the output connector 19 other than the lead wire 43, and the opening 6e. The clearance 33 is eliminated as much as possible. A highly light reflective material is used for the input connector 18 and the output connector 19. As this highly light-reflective material, for example, a highly light-reflective material such as aluminum or silver, or an inorganic material such as fine titanium oxide (TiO ₂ ) or barium titanate (BaTiO ₃ ), similar to the white solder resist 61. In addition, an organic material such as a fine tempered acrylic having a countless number of holes for light scattering and polycarbonate is used. This highly light-reflective material may be applied to the surfaces of the input connector 18 and the output connector 19, or may be used as a material for the body case itself of the input connector 18 and the output connector 19. It doesn't matter.

  Further, in the portion of the reflecting plate 6 located above the lead wire 43, a cut 82 is made along two sides in the Y direction of the opening 6e, and the cut portion is Z direction with the X direction as an axis. The opening 6e is widened so that the lead wire 43 does not interfere, and the flap portion 81 is formed.

  With such a configuration, even when light hits the surfaces of the input connector 18 and the output connector 19, the light can be reflected by the high light reflective material, and the flap portion 81 allows the input connector 18 and Since the light incident on the vicinity of the lead wire 43 of the output connector 19 can be reflected, it is possible to prevent the loss of light without providing a new member on the reflection plate 6 and to reduce the luminance of the backlight device 10. Uneven brightness can be prevented.

  In the present embodiment, the reflection plate 6 may be cut and provided with a flap portion similar to the above also in the vicinity of the screw 32 on the wiring board 22. Further, instead of providing the flap portion, the clearance between the opening 6f exposing the screw 32 and the screw 32 may be made as small as possible, and the high light reflective material may be used on the exposed surface. Thereby, the loss of light can be further suppressed.

(Third embodiment)
Next, a third embodiment of the present invention will be described. FIG. 11 is a partial cross-sectional view of the vicinity of the input connector 18 on the wiring board 22 of the backlight device 10 according to the present embodiment.

  As shown in the figure, in the present embodiment, the formation method and shape are changed as compared with the flap portion 81 shown in FIG. 10 of the second embodiment. That is, in the present embodiment, the reflective plate 6 is cut along the three sides of the rectangular surfaces of the input connector 18 and the output connector 19 without cutting off the portions facing the input connector 18 and the output connector 19. An opening 6e and a flap portion 81 are formed so that only the cut is made and the cut portion is floated. The flap portion 81 has an inclined portion 81a that extends obliquely upward from the surface of the reflecting plate 6, and a flat portion 81b that is bent from the inclined portion 81a so as to be substantially parallel to the surface of the reflecting plate 6. is doing.

  By adopting such a configuration, as in the case of the flap portion 81 in the second embodiment, the flap portion 81, the input connector 18 and the output connector 19 in the Z direction compared to the case of only the inclined surface. Since the clearance can be reduced, it is possible to prevent light from entering from the clearance as much as possible. And since the light reflected from the diffusion plate 5 side to the reflection plate 6 side can be more reliably reflected to the diffusion plate 5 side by the flat portion 81b, the loss of light can be prevented with a higher probability. Further, since the input connector 18 and the output connector 19 are substantially covered with the flat portion 81b, the loss of light is minimized as much as possible without using a highly reflective material on the surfaces of the input connector 18 and the output connector 19. Can be prevented. Of course, a high light reflective material may be used for the input connector 18 and the output connector 19 as in the second embodiment.

  Further, in the present embodiment, a flap portion having a flat portion and an inclined portion may be formed on the reflector also in the vicinity of the screw 32 on the wiring board 22 in the same manner as described above.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. FIG. 12 is a partial cross-sectional view of the vicinity of the input connector 18 on the wiring board 22 of the backlight device 10 according to this embodiment.

  In the second and third embodiments described above, the flap portion 81 is formed on the reflector 6. However, in the present embodiment, as shown in FIG. 6, a convex portion 91 is formed integrally with the opening 6e by projecting a portion facing the input connector 18 and the output connector 19 to the diffusion plate 5 side in the Z direction. The convex portion 91 can be easily formed by a molding technique such as press working. As a result, no clearance is generated in the reflecting plate 6, so that loss of light can be reliably prevented without providing a new member in the reflecting plate 6.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  In each of the above-described embodiments, measures are taken to prevent loss of light when the reflector 6 is provided with the openings 6e and 6f for exposing the input connector 18, the output connector 19 and the screw 32. As described above, this measure is not limited to connectors and screws. For example, pins and other protrusions project on the wiring board 22 as the backlight device 10 becomes thinner and interfere with the reflector 6. Anything that can be used.

  The shapes of the flap portion 81 and the convex portion 91 in the second to fourth embodiments described above are not limited to those illustrated in FIGS. 10 to 12, and may be formed in any other shape such as a curved surface, for example. it can.

1 is a schematic exploded perspective view of a liquid crystal display device having a backlight device according to a first embodiment of the present invention. FIG. 2 is a partial cross-sectional view in the Z direction of the liquid crystal display device of FIG. 1. 1 is a partially cutaway plan view showing a configuration of a backlight device according to a first embodiment of the present invention. FIG. 4 is an enlarged view of a portion surrounded by a broken line A in FIG. 3 in the backlight device according to the first embodiment of the present invention. It is AA 'sectional drawing of the backlight apparatus shown in FIG. It is a fragmentary sectional view of the connector vicinity of the wiring board shown in FIG. In the 1st Embodiment of this invention, it is the figure which showed the result of having measured the brightness | luminance of the backlight apparatus at the time of providing a reflective sheet in the opening for connector exposure of a reflecting plate. 1 is a block diagram illustrating a driving circuit of a liquid crystal display device according to a first embodiment of the present invention. It is a partial top view of the backlight apparatus which concerns on the 2nd Embodiment of this invention. It is a fragmentary sectional view of the connector vicinity of the wiring board shown in FIG. It is a fragmentary sectional view of the connector vicinity of the wiring board in the backlight apparatus which concerns on the 3rd Embodiment of this invention. It is a fragmentary sectional view of the connector vicinity of the wiring board in the backlight apparatus which concerns on the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Front chassis 2 ... Liquid crystal panel 3 ... Middle frame 4 ... Optical sheet laminated body 5 ... Diffusing plate 6 ... Reflecting plate 6e ... Opening 6f ... Opening 7 ... Light source array 8 ... Back chassis 10 ... Backlight apparatus 16 ... Array base 17 ... Optical stud 20 ... Light source device 21 ... LED
DESCRIPTION OF SYMBOLS 22 ... Wiring board 23 ... Adhesive material 31 ... Reflection sheet 33 ... Clearance 43 ... Lead wire 52 ... Thermal via 53 ... Metal plating layer 61 ... White solder resist 81 ... Flap part 81a ... Inclination part 81b ... Plane part 82 ... Notch 91 ... Convex part 100 ... Liquid crystal display device

Claims (13)

A plurality of wiring boards provided so that a plurality of light emitting diodes and a connector for inputting or outputting a signal for lighting each light emitting diode are projected;
A first opening for exposing each light emitting diode in the projecting direction and a second opening for exposing the connector in the projecting direction are provided on the surface. And a reflector capable of reflecting the light emitted from each of the light emitting diodes;
A diffusion plate that is provided so as to face the reflection plate, reflects a part of the light to the reflection plate side, transmits the other part of the light, diffuses it, and emits it;
The provided so as to cover at least part of the second opening of the reflector, provided to Luba backlight device and capable of reflecting coating portion the light. The backlight device according to claim 1,
The covering portion is a sheet material affixed to the reflector so as to cover the second opening.
Backlight device. The backlight device according to claim 1,
The covering portion is a flap portion formed by cutting a portion of the reflecting plate facing the connector so as to form the second opening and bending the cut portion so as to float in the protruding direction. Is
Backlight device. The backlight device according to claim 3,
The connector has a highly light reflective material on its exposed surface
Backlight device. The backlight device according to claim 3,
The flap portion has a flat portion substantially parallel to the surface of the reflector.
Backlight device. The backlight device according to claim 1,
The covering portion is a high light reflective material that the exposed surface of the connector has.
Backlight device. The backlight device according to claim 1,
The covering portion is a convex portion formed integrally with the second opening by causing a portion of the reflecting plate facing the connector to protrude in the protruding direction.
Backlight device. A plurality of wiring boards provided so that a plurality of light emitting diodes protrude;
A holding member for holding each of the wiring boards;
Each of the wiring boards can be locked to the holding member, and a locking member provided so that at least a part protrudes from each of the wiring boards;
A first opening for covering each wiring substrate and exposing each light emitting diode in the protruding direction and a second opening for exposing the locking member in the protruding direction are provided on the surface. And a reflector capable of reflecting the light emitted from each of the light emitting diodes,
A diffusion plate that is provided so as to face the reflection plate, reflects a part of the light to the reflection plate side, transmits the other part of the light, diffuses it, and emits it;
The provided so as to cover at least part of the second opening of the reflector, provided to Luba backlight device and capable of reflecting coating portion the light. The backlight device according to claim 8, wherein
The covering portion is a sheet material affixed to the reflector so as to cover the second opening.
Backlight device. The backlight device according to claim 8, wherein
The covering portion is a high light reflective material that the exposed surface of the locking member has.
Backlight device. The backlight device according to claim 8, wherein
The covering portion is a convex portion formed integrally with the second opening by causing a portion of the reflecting plate facing the locking member to protrude in the protruding direction.
Backlight device. A plurality of light emitting diodes and a plurality of wiring boards provided so as to project a connector for inputting or outputting a signal for lighting each light emitting diode, and provided to cover each wiring board, A first opening for exposing each light emitting diode in the protruding direction and a second opening for exposing the connector in the protruding direction are provided on the surface, and the light emitted from each light emitting diode is A reflective plate that can be reflected, and a diffuser plate that is provided so as to face the reflective plate, reflects a part of the light to the reflective plate side, transmits the other part of the light and diffuses it, and emits A backlight device having a covering portion provided so as to cover at least a part of the second opening of the reflecting plate and capable of reflecting the light;
It said to that liquid crystal display device and a liquid crystal panel capable of displaying an image by changing the transmittance of light emitted from the diffusion plate. A plurality of wiring boards provided so that a plurality of light emitting diodes protrude, a holding member holding each wiring board, and each wiring board can be locked to the holding member, and at least from each wiring board A locking member provided so as to partially protrude, a first opening provided so as to cover each of the wiring boards, and exposing each of the light emitting diodes in the protruding direction, and the locking member. A second opening for exposing in the protruding direction on the surface, a reflection plate capable of reflecting the light emitted from each of the light emitting diodes, and provided to face the reflection plate; A diffusion plate for reflecting a part of the light to the reflection plate side and transmitting the other part of the light to be diffused and emitted, and to cover at least a part of the second opening of the reflection plate, Cover that can reflect light A backlight device and a part,
It said to that liquid crystal display device and a liquid crystal panel capable of displaying an image by changing the transmittance of light emitted from the diffusion plate.