JP2005085689A - Planar light source device and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformalize the brightness of a planar light source device using a U-shaped lamp. <P>SOLUTION: The planar light source device has a plurality of nearly U-shaped lamps 27 disposed on a rear surface of a light emitting region. It is equipped with a rear frame 30 encasing the lamps 27 comprising a right-side lamps 27a disposed along a first side of the light emitting region and a left-side lamps 27b disposed along a second side opposite to the first side. Bending portions of the right-side lamps 27a and the left-side lamps 27b are disposed in the central part of the light emitting region in the X direction. The right-side lamps 27a and the left-side lamps 27b are disposed at nearly the same height from the rear frame 30 opposing to each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a planar light source device and a display device, and more particularly to a planar light source device and a display device having a linear light source on the back side.

  As an image display device for personal computers and other various monitors, a liquid crystal display device is widely used. The liquid crystal display device typically includes a liquid crystal display panel and a backlight unit disposed on the back surface thereof. The liquid crystal display panel displays an image by controlling the transmitted light based on the display signal.

  The backlight unit includes a side light type (edge light type) backlight unit in which a light source is disposed on a side surface and guided to the entire surface by a light guide plate, and a direct type backlight unit in which a light source is disposed on the back surface. The sidelight type backlight unit is suitable for thinning the liquid crystal display device, but the light use efficiency is low. On the other hand, the direct type backlight unit has a high light use efficiency and can provide a liquid crystal display device with high luminance. Therefore, the direct type backlight unit is suitable for a large liquid crystal display. A liquid crystal display device using this direct type backlight unit uses a large display having a size of 40 inches or more.

  On the other hand, a fluorescent lamp such as a cold-cathode tube lamp that emits high-luminance light is suitable for a light source of a direct type backlight unit used in such a large liquid crystal display device. Usually, a fluorescent lamp is coated with a phosphor inside a glass tube, electrodes are attached to both ends of the tube, and argon as a buffer gas and an appropriate amount of mercury (xenon is also used) are enclosed in the tube. When a voltage is applied to the electrode, electrons are ejected from the cathode, the electrons hit mercury in the glass tube to excite mercury, and mercury emits ultraviolet rays. This ultraviolet light becomes visible light on the phosphor applied to the inside of the glass tube, and white light is emitted.

  When the fluorescent lamp is placed in a direction perpendicular to the ground, the mercury falls down due to gravity and the temperature difference between the upper and lower sides, and thus uneven brightness occurs in the upper and lower sides. Therefore, in the backlight unit, a linear fluorescent lamp is usually placed in the horizontal direction (longitudinal direction) of the display area. Further, when the liquid crystal display device is increased in size, the length of the fluorescent lamp is increased accordingly. For this reason, when a linear fluorescent lamp is used, the following problems occur.

  If the fluorescent lamp becomes too long, the diameter of the tube may become uneven in the length direction due to manufacturing problems. If the tube diameter becomes non-uniform, the electron density in the longitudinal direction of the tube changes, resulting in uneven brightness in the horizontal direction of the display screen. Such non-uniformity of the tube diameter is a problem in the manufacture of glass tubes, and this problem appears particularly when the length of the linear portion of the fluorescent lamp is 1600 mm or more. The limit is about 1500 mm.

  Further, a backlight illumination device having a fluorescent lamp bent in a U shape or a fluorescent lamp having a winding shape has been developed (for example, Patent Document 1). However, in this configuration, since the curved portion is in the vicinity of the end of the backlight illumination device, the lateral dimension of a 40-inch or larger backlight is about 900 mm, and a fluorescent lamp with a length of 1800 mm is required to make a U shape. Necessary and not feasible. Even if it can be realized, there is a problem that it becomes difficult to handle a fluorescent lamp having an outer diameter of φ2 to φ8 mm. Further, there is a problem that the luminance near the edge of the display area becomes strong and asymmetric luminance unevenness occurs on the left and right or top and bottom of the display area. On the other hand, in a liquid crystal display device used as a television monitor, it is desirable that the central luminance of the display area is high, but there is also a problem that the luminance at the edge of the display area becomes strong.

Japanese Patent Laid-Open No. 2000-503463 (FIGS. 2 to 4)

Thus, in the conventional liquid crystal display device using a U-shaped lamp, since it is difficult to manufacture a fluorescent lamp for a large-sized display of 40 inches or more, even if it can be realized, There is a problem that it is difficult to make the luminance uniform.
The present invention has been made in view of such problems, and an object thereof is to provide a planar light source device and a display device having uniform luminance.

  The planar light source device (backlight unit 12 in the embodiment of the present invention) according to the present invention is a substantially U-shaped linear light source (for example, in the embodiment of the present invention) disposed on the back surface of the light emitting region. A planar light source device having a plurality of lamps 27), the first linear light source group having a plurality of the linear light sources arranged along the first side of the light emitting region (for example, implementation of the present invention) And a second linear light source group having a plurality of the linear light sources arranged along the second side facing the first side (for example, implementation of the present invention) Left frame 27b) and a frame (for example, an embodiment of the present invention) that is provided on the back surface of the first linear light source group and the second linear light source group and accommodates the linear light source. A rear frame 28) in the form, The curved portion of the linear light source of the first linear light source group and the curved portion of the linear light source of the second linear light source group are perpendicular to the first side and the second side (for example, the present invention). (In the X direction in the above embodiment) is arranged at the center of the light emitting region. Thereby, even if it is a case where a U-shaped light source is used, the brightness | luminance of the center part of a light emission area | region can be made high.

  In the linear light source device described above, the curved portion of the linear light source of the first linear light source group and the curved portion of the linear light source of the second linear light source group are arranged to face each other. desirable. Thereby, the brightness | luminance of a planar light source device can be made uniform.

  In the above-described linear light source device, the linear light sources of the first linear light source group and the linear light sources of the second linear light source group are provided at substantially the same height from the bottom surface of the frame. desirable. Thereby, the brightness | luminance of a planar light source device can be made uniform and can be reduced in thickness.

  The planar light source device according to the present invention is the above-described linear light source device, further comprising a fixture that is provided in the light emitting region and fixes the linear light source, and the linear light source and the frame by the fixture. Is provided substantially in parallel with the bottom surface. Thereby, the impact resistance of the linear light source can be improved, the luminance of the planar light source device can be made uniform, and the thickness can be reduced.

    The planar light source device according to the present invention is a diffusion plate (for example, an embodiment of the present invention) that is provided on the light emitting surface side of the linear light source and diffuses light from the linear light source. And a diffusion plate support (for example, the diffusion plate support 53 in the embodiment of the present invention) provided on the fixture and supporting the diffusion plate. Thereby, it is not limited to arrangement | positioning of a linear light source, Many diffuser plate supports can be provided, and even if it is a case where a planar light source device enlarges, the bending of a diffuser plate can be reduced.

  The planar light source device according to claim 5, wherein the fixture is made of metal. Thereby, the cooling performance of the linear light source can be improved, and the lifetime of the linear light source can be extended.

  A display device according to the present invention includes the above-described planar light source device and a display panel (for example, the liquid crystal display panel 11 in the present embodiment) provided on the light emitting surface side of the planar light source device. . Thereby, the display characteristics of the display device can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the planar light source device with the high center brightness | luminance of the light emission area | region, and the asymmetrical brightness nonuniformity reduced, and a display apparatus using the same can be provided.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description is to describe the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description is omitted and simplified as appropriate. Further, those skilled in the art will be able to easily change, add, and convert each element of the following embodiments within the scope of the present invention. In addition, what attached | subjected the same code | symbol in each figure has shown the same element, and abbreviate | omits description suitably.

  The configuration of the liquid crystal display device according to this example will be described with reference to FIG. FIG. 1 is an exploded perspective view showing the configuration of the liquid crystal display device. 10 is a casing, 11 is a liquid crystal display panel, 12 is a backlight unit, and 13 is a control board.

  The liquid crystal display device according to the present invention includes a liquid crystal display liquid crystal display panel 11 and a backlight unit 12 provided on the back side thereof. The liquid crystal display panel 11 has a display area composed of a plurality of pixels arranged in a matrix and a frame area that is an outer peripheral area of the display area. The liquid crystal display panel 11 has an array substrate on which an array circuit is formed and a counter substrate, and liquid crystal is sealed between the two substrates. An active matrix type liquid crystal display panel includes a switching element in which each pixel controls input / output of a display signal. A typical switching element is a TFT (Thin Film Transistor).

  The color liquid crystal display device has an RGB color filter layer on a counter substrate. Each pixel in the display area of the liquid crystal display panel 11 performs RGB color display. Of course, a black and white display displays either white or black. The liquid crystal display panel displays an image by controlling the transmitted light from the backlight unit. In the display area on the array substrate, a plurality of source lines and a plurality of gate lines are arranged in a matrix. The source line and the gate line are disposed so as to overlap each other at a substantially right angle, and the TFT is disposed in the vicinity of the intersection.

  Each pixel selected by the gate voltage input from the gate driver IC applies an electric field to the liquid crystal based on the display signal voltage input from the source driver IC. The control board 13 is provided on the back side of the backlight unit 12 and supplies signals to the gate line and the source line via an FPC or the like. Further, the control board 13 supplies power to the backlight lamp via an inverter or the like. The liquid crystal display panel 11 and the backlight unit 12 are enclosed in a casing 11 made of metal or the like, and are fixed by screws or the like.

  The configuration of the backlight unit 12 will be described with reference to FIG. FIG. 2 is an exploded perspective view showing the configuration of the backlight unit 12. 21 is a front frame, 22 is a diffusion sheet, 23 is a lens sheet, 24 is a diffusion sheet, 25 is a diffusion plate, 26 is a lamp support, 27 is a lamp, 28 is a lamp holder, 29 is a reflection sheet, 30 is a rear frame, 31 is an O-ring and 32 is a spacer pin.

  In this embodiment, a direct type backlight unit 12 in which a light source is provided on the back side of the display area is used. The backlight unit 12 uses a U-shaped lamp 27 as a light source. The lamp 27 is a fluorescent lamp such as a cold cathode tube lamp. In general, fluorescent lamps are coated with phosphor on the inside of a glass tube, electrodes are attached to both ends of the tube, and argon and neon as buffer gases and an appropriate amount of mercury (xenon is also used) are enclosed in the tube. . When a voltage is applied to the electrode, electrons are ejected from the cathode, the electrons hit mercury in the glass tube to excite mercury, and mercury emits ultraviolet rays. This ultraviolet light becomes visible light on the phosphor applied to the inside of the glass tube, and white light is emitted.

  The backlight unit 12 includes a rear frame 30 for housing the lamp 27 on the back side. The rear frame 30 has a substantially rectangular metal plate bent at the end on the long side. Thereby, a part of the side surface and the bottom surface of the planar light source device are formed. Two side surfaces formed on the outer side from the bent portion are spread to the upper surface side at an angle lower than a right angle, and the lamp 27 is disposed on the bottom surface between the two side surfaces. The depth of the rear frame 30 is about 10 to 50 mm. The end on the short side of the rear frame 30 is open to attach the lamp 27 and the lamp support 26. A reflective sheet 29 is affixed to the upper surface of the rear frame 30, and reflects light from the lamp 27 to the upper surface side (display surface side).

  A plurality of U-shaped lamps 27 are arranged in two rows on the upper surface of the reflection sheet 29. Each lamp 27 includes two parallel straight portions and a curved portion connecting the straight portions. The straight part and the curved part are constituted by one glass tube. Electrodes are provided at the ends of the respective straight portions opposite to the curved portions, and lamp holders 28 are attached corresponding to the electrodes. A lead wire connected to the electrode extends from the lamp holder 28, and a voltage can be applied via a connector or the like.

  A rod-shaped lamp support portion 26 is attached to the end portion of the rear frame 30 on the short side side along the short side in order to fix the lamp 27. The lamp support portion 26 is fitted to the side surfaces on both sides of the rear frame 30 from above with the lamp 27 placed on the rear frame 30. The lamp support 26 is provided with a U-shaped opening on the lower side corresponding to the shape of the lamp holder 28. When the lamp holder 28 is attached from above, the lamp holder 28 is inserted into the opening, and is sandwiched between the rear frame 30 and the lamp 27 is fixed. One lamp support portion 26 is provided with 12 openings corresponding to the number of the lamps 27 so that each of the six lamps 27 can be fixed at two locations. The six lamps 27 have the same shape and are arranged in parallel. Further, the lamp support portion 26 is provided so as to face the end portion on the short side, and a total of 12 lamps 27 are arranged in the backlight unit. The lamp support 26 is inclined on the inner side surface and extends to the upper surface side in the same manner as the rear frame 30.

  A diffusion plate 25 is placed on the lamp support portion 26. For the diffusion plate 25, for example, PC (polycarbonate) or PMMA (polymethyl methacrylate) having a thickness of 2 mm can be used. On the diffusion plate 25, a diffusion sheet 24, a lens sheet 23, and a diffusion sheet 22 are placed in order from the bottom. The diffusion sheet 24, the lens sheet 23, and the diffusion sheet 22 are optical sheets each having a thickness of about 0.2 to 0.3 mm. The diffusion plate 25, the diffusion sheet 24, the lens sheet 23, and the diffusion sheet 22 are provided on the entire surface of the light emitting region. The diffusing plate 25, the diffusing sheet 24, and the diffusing sheet 22 diffuse the light from the lamp 27 to make the luminance in the display surface uniform. The lens sheet 23 polarizes and emits radiation characteristics of incident light from the lamp 27.

  A frame-shaped front frame 21 is attached to the rear frame 30 from above. Ends on the long side of the diffusion plate 25, the diffusion sheet 24, the lens sheet 23, and the diffusion sheet 22 are sandwiched between the front frame 21 and the rear frame 30. The end portions on the short side of the diffusion plate 25, the diffusion sheet 24, the lens sheet 23, and the diffusion sheet 22 are sandwiched between the front frame 21 and the rear frame 30 via the lamp holder 28. Thereby, the diffusion plate 25, the diffusion sheet 24, the lens sheet 23, and the diffusion sheet 22 are positioned and fixed. The front frame 21 and the rear frame 30 may be fixed by screws or the like.

  The light emitted from the lamp 27 enters the diffuser plate 25 directly or after being reflected by the reflection sheet 29. The light incident on the diffusion plate 25 is diffused by the diffusion plate 25 and the diffusion sheet 24 and enters the lens sheet 23. The light incident on the lens sheet 23 is polarized and enters the diffusion sheet 22. The light incident on the diffusion sheet 22 is diffused and emitted from the area inside the front frame 21 toward the liquid crystal display panel 11 shown in FIG. Here, since the rear frame 30 and the lamp support portion 26 are inclined and spread upward, the backlight extends not only to the bottom surface of the rear frame but also to the expanded area on the side surface of the rear frame 30 and the upper side of the lamp support portion 26. -It becomes the light emission area of the unit 12. The backlight unit 12 functions as a planar light source device that emits light uniformly over the entire surface. The light emitted from the backlight unit 12 enters the liquid crystal display panel 11 shown in FIG. 1, is selectively transmitted by the liquid crystal display panel 11, and displays a desired image.

  Each of the U-shaped lamps 27 is fitted in the O-ring 31. The O-ring 31 is fitted from the end side of the lamp 27 and attached to the straight portion of the lamp 27 before the lamp holder is attached. Two O-rings 31 are symmetrically attached to one lamp 27. The O-ring 31 serves as a spacer between the lamp 27 and the reflection sheet 29, and a certain gap is left between the lamp 27 and the bottom surface of the reflection sheet 29. Since the front end portion of the lamp 27 is supported by the lamp holder 28, the lamp 27 is maintained at a certain distance from each other, and each lamp 27 is disposed substantially parallel to the bottom surface. Further, all the lamps 27 are arranged at substantially the same height from the bottom surface of the rear frame 30. Thereby, the brightness | luminance of a light emission area | region can be made uniform. Further, by providing the lamp 27 with the O-ring 31, the impact resistance of the lamp 27 can be improved.

  A spacer pin 32 is attached to the center of the bottom surface of the rear frame 30. The spacer pins 32 are fixed from the rear side of the rear frame 30 with screws or the like. In a position corresponding to the spacer pin 32 of the reflection sheet 29, a hole (not shown) having a size substantially the same as the size of the spacer 32 is opened in the center in order to penetrate the spacer pin 32. The spacer pin 32 is a cone having a height substantially the same as or slightly lower than the depth of the rear frame 30, and makes point contact with the center of the back surface of the diffusion plate 25. Thereby, the spacer pin 32 supports the diffusion plate 25 so that the diffusion plate 25 does not bend.

  The reflection sheet 29 is made of, for example, a white PET (polyethylene terephthalate) sheet so as to reflect light from the lamp 27 toward the display surface. The reflection sheet 29 is attached to the rear frame 30 with, for example, a double-sided tape. The spacer pins 32 and the lamp support 26 are molded products of white polycarbonate (PC), and reflect the light from the lamp 27 with high reflectivity. Thereby, since light absorption can be reduced, the light from the lamp 27 can be efficiently reflected to the display surface side, and the light utilization efficiency can be improved.

  The arrangement of the plurality of lamps 27 will be described with reference to FIG. FIG. 3A is a top view showing a simplified configuration of the backlight unit from which the front frame 21 to the diffusion plate 25 are removed. 3B is a cross-sectional view taken along the line AA in FIG. 3A, and FIG. 3C is a cross-sectional view taken along the line BB in FIG. 3A. 3, the long side direction of the light emitting region is the X direction, the short side direction is the Y direction, and the direction perpendicular to the light emitting surface is the Z direction. For the sake of explanation, the X direction is the left-right direction. In FIG. 2, 27a is a right lamp, 27b is a left lamp, 41 is a straight portion of the lamp, and 42 is a curved portion of the lamp. 43 indicates a center line in the X direction in the light emitting region, and 44 indicates a center line in the Y direction in the light emitting region. Reference numeral 45 denotes a center point of the light emitting region, which is an intersection of the center line 43 in the X direction and the center line 44 in the Y direction.

On the right side of the rear frame 30, six U-shaped lamps 27a are arranged at equal intervals along the short side (Y direction). This lamp 27a is referred to as a right lamp 27a. Similarly, six U-shaped lamps 27b are provided on the left side of the rear frame 30 at equal intervals along the short side (Y direction). This lamp 27b is referred to as a left lamp 27b. The six left lamps 27b opposite to the six right lamps 27a are provided symmetrically with respect to the center line 43 in the X direction. Each lamp 27 is attached so that the curved portion 42 is at the center of the light emitting region in the X direction, and the end of the lamp 27 having an electrode is disposed at the end of the light emitting region in the X direction. The linear portions 41 of the lamps 27 are attached so as to be parallel to the X axis.
The lamp 27 is, for example, a glass tube having an outer diameter of φ3 to φ4, and the distance between the straight portions 41 in one lamp 27 is about 30 to 40 mm. The interval between the right lamps 27a arranged at equal intervals is, for example, 30 to 40 mm. Similarly, the interval between the left lamps 27b arranged at equal intervals is, for example, 30 to 40 mm. The curved portion 42 of the right lamp 27a and the curved portion 42 of the left lamp 27b are arranged close to each other in the vicinity of the center line 43 in the X direction, and the distance between them is the position where the lamp 27 is closest. About 30 mm.

  Thus, by providing the right lamp 27a and the left side 27b symmetrically with respect to the center line 43 in the X direction, the luminance in the light emitting region is symmetric in the X direction. Further, by arranging the right lamp 27a and the left lamp 27b at equal intervals, the lamps can be provided symmetrically with respect to the center line 44 in the Y direction. Therefore, the brightness of light is also symmetric in the Y direction. As a result, light emission from the lamp becomes point-symmetric with respect to the center point 45 in the light-emitting region. Therefore, uneven brightness on the left and right or top and bottom of the display screen can be eliminated as compared with the case where the curved portion 42 is arranged at the end of the light emitting region.

  By providing the curved portion 42 of the lamp 27 at the central portion of the light emitting region in the X direction, the light emission length of the lamp 27 in the vicinity of the central portion can be increased. Therefore, the central luminance of the light emitting region can be improved. In general, since the inner diameter of the curved portion 42 tends to be smaller than the inner diameter of the straight portion 41 even if the outer diameter of the glass tube is uniform, the discharge current density in the curved portion 42 is larger than the current density in the straight portion 41. Also gets higher. Thereby, since the brightness | luminance of the curved part 42 becomes higher than the linear part 41, the brightness | luminance of the center of a X direction can be raised further.

  When the curved portion 42 is arranged at the end of the light emitting region, in order to make the light emission from the lamp symmetrical in the light emitting region, it is necessary to overlap the lamps or make the curved portion 42 of the lamp a non-light emitting region. In the present invention, since the curved portion 42 is provided at the center of the light emitting region, the frame region can be narrowed. Further, since it is not necessary to stack the lamps 27, the thickness can be reduced. With this configuration, light can be used more efficiently. By providing the curved portion 42 at the center of the light emitting region, even when a U-shaped lamp is used, the overall length of the straight portion 41 of the lamp 27 can be shortened, and the lamp 27 in the straight portion 41 can be reduced. The inner diameter can be made uniform. Furthermore, since the entire length of the lamp can be shortened as compared with the configuration in which the curved portion 42 is arranged at the end of the light emitting region, the discharge voltage of the lamp 27 can be reduced. As a result, the capacity of the inverter for supplying power to the lamp 27 can be reduced. Furthermore, since the width of the lamp 27 in the X direction can be shortened, the handling of the lamp 27 is facilitated and the attachment can be easily performed. Thereby, assembly property can be improved.

  Each lamp 27 has an O-ring 31 attached to a straight portion 41. O-rings 31 are symmetrically arranged in each lamp 27. Since all the O-rings 31 are formed in the same shape, all the lamps 27 are fixed at substantially the same height from the bottom surface of the rear frame 30. In addition, the O-ring 31 and the lamp holder 28 allow each lamp 27 to be arranged in parallel with the bottom surface of the rear frame 30 with a certain gap. Since all the lamps 27 are provided at the same height from the bottom surface of the rear frame 30, it is possible to make the liquid crystal display device thinner than when the lamps 27 are stacked in the Z direction. Furthermore, the impact resistance of the lamp 27 can be improved by providing the lamp 27 with the O-ring 31.

  In the backlight unit of the above-described embodiment, the configuration such as the size and arrangement of the lamps 27 is an example, and is not limited to the configuration described. For example, a large display device of 50 inches uses 15 lamps 27 on one side and all 30 lamps. Furthermore, the material of a component is a typical example, and is not limited to the contents described.

  In the above-described backlight unit, the lamp 27 is fixed by an O-ring, but can be fixed by a lamp fixture described below. This lamp fixture will be described with reference to FIG. FIG. 4 is a side view showing the configuration of the lamp fixture. 50 is a lamp fixing tool, 51 is a hole of the lamp fixing tool 50, 52 is a convex part of the lamp fixing tool 50, 53 is a diffusion plate support, 54 is an upper holding part, and 55 is a lower holding part.

  As shown in FIG. 4A, the rear frame 30 has a hole for attaching the lamp fixture 50. At the lower part of the lamp fixture 50, holding portions 54 and 55 that are slightly wider than the holes of the rear frame are provided to face each other. The lamp fixture 50 is attached by holding the rear frame 30 between the upper holding portion 54 and the lower holding portion 55. The lamp fixture 50 is made of a material such as silicon rubber, which is partially elastic. Since the upper holding portion 55 is tapered and narrows toward the lower side, it can be inserted into the hole of the rear frame 30. The lamp fixture 50 is further provided with a hole 51 for inserting the lamp 27 and a convex portion 52 for fixing the diffusion plate support 53 on the holding portion 54. When the lower holding portion 55 is inserted into the hole of the rear frame 30 from above, the rear frame 30 is held between the lower holding portion 55 and the upper holding portion 54. . Since the upper holding portion 54 and the lower holding portion 55 are wider than the width of the hole of the rear frame 30, the lamp fixture 50 is securely fixed to the rear frame 30.

  The upper part of the hole 51 of the lamp fixture 50 is opened with a width slightly narrower than the outer diameter of the lamp 27 so that the lamp 27 can be inserted from above. Since the lamp fixture 50 has elasticity, when the lamp 27 is inserted into the hole 51 from above, the open portion at the top of the hole 51 is further opened and the lamp 27 is stored. The lamp 27 is accommodated in the hole 51, and the upper part of the hole 51 is returned to the original position, and the lamp 27 is fixed. Therefore, the lamp 27 is securely fixed by the lamp fixture 50 and the lamp holder 26 so as to be parallel to the bottom surface.

  A conical diffusion plate support 53 is attached from above. A convex portion 52 is provided on the upper surface of the lamp fixture 50, and a concave portion is provided on the lower surface of the diffusion plate support 53 so as to correspond to the convex portion 52. The diffusion plate support 53 is fixed by fitting the concave portion into the convex portion 52. Similar to the spacer pin 32 shown in FIG. 2, the diffusion plate support 53 is in contact with the lower surface of the diffusion plate 25 so that the diffusion plate 25 does not bend and supports the diffusion plate 25 from below. As a result, the configuration shown in FIG. The lamp fixture 50 and the diffusion plate support 53 are formed of a white resin or the like so that light can be used efficiently. By providing the diffusion plate support 53 on the lamp fixture 50 in this way, the number of the diffusion plate supports 53 can be increased without being limited to the arrangement of the lamps 27. Thereby, even if it is a large sized planar light source device, the bending of a diffuser plate can be reduced. The lamp fixture 50 may be attached only to some of the lamps 27. In this case, it is desirable to provide the lamp fixture 50 symmetrically in the light emitting region in order to make the luminance uniform.

  Note that the shape, material, and the like of the lamp fixture described above are not limited to the configurations described. For example, the lamp fixture may be formed of a material having good thermal conductivity such as metal in order to cool the lamp 27. When metal is used for the lamp fixture, for example, the lamp fixture can be fixed with screws from the back side of the rear frame 30. Thereby, it is possible to extend the life of the lamp 27 by improving the cooling capacity of the lamp 27, that is, supplementing mercury and preventing unnecessary consumption at the electrode portion.

  In the above description, the shape of the lamp 27 is U-shaped. However, the same effect can be obtained even when the lamp is bent in a U-shape. A lamp having a U-shape or a straight portion and a curved portion and having a shape similar to a U-shape or a U-shape is included.

It is a disassembled perspective view which shows the structure of the liquid crystal display device concerning a present Example. It is a disassembled perspective view which shows the structure of the backlight unit concerning this invention. It is the schematic which shows the structure of the backlight unit concerning this invention. It is a side view which shows the structure of the lamp fixture of the backlight unit concerning this invention.

Explanation of symbols

10 housing, 11 liquid crystal display panel, 12 backlight unit, 13 control board,
21 front frame, 22 diffusion sheet, 23 lens sheet, 24 diffusion sheet,
25 diffuser plate, 26 lamp support, 27 lamp, 27a right lamp,
27b Left lamp, 28 Lamp holder, 29 Reflective sheet, 30 Rear frame 31 O-ring, 32 Spacer pin,
41 straight part, 42 curved part, 43 center line in X direction, 44 center line in Y direction,
50 lamp fixture, 51 hole, 52 convex, 53 diffusion plate support,
54 Upper holding part, 55 Lower holding part

Claims (7)

A planar light source device comprising a plurality of substantially U-shaped linear light sources arranged on the back surface of a light emitting region,
A first linear light source group having a plurality of the linear light sources arranged along the first side of the light emitting region;
A second linear light source group having a plurality of the linear light sources arranged along a second side facing the first side;
A frame that is provided on the back surface of the first linear light source group and the second linear light source group, and that houses the linear light source;
The curved portion of the linear light source of the first linear light source group and the curved portion of the linear light source of the second linear light source group emit the light in a direction perpendicular to the first side and the second side. A planar light source device disposed in the center of the region.   The planar light source device according to claim 1, wherein a curved portion of the linear light source of the first linear light source group and a curved portion of the linear light source of the second linear light source group are arranged to face each other.   3. The planar light source according to claim 1, wherein the linear light source of the first linear light source group and the linear light source of the second linear light source group are provided at substantially the same height from the bottom surface of the frame. apparatus. A fixture that is provided in the light emitting region and fixes the linear light source;
The planar light source device according to claim 1, wherein the linear light source and a bottom surface of the frame are provided substantially in parallel by the fixture. A diffusion plate that is provided on the light emitting surface side of the linear light source and diffuses light from the linear light source;
The planar light source device according to claim 4, further comprising a diffusion plate support that is provided on the fixture and supports the diffusion plate.   The planar light source device according to claim 5, wherein the fixture is made of metal. A surface light source device according to any one of claims 1 to 6,
And a display panel provided on a light emitting surface side of the planar light source device.

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