JP6737617B2 - Backlight device - Google Patents

Description

The present invention relates to a backlight device used for a transmissive display device such as a liquid crystal display (LCD).

An example of an LCD, which is a type of conventional display device, is shown in FIGS. FIG. 5 is a side sectional view of a conventional LCD, FIG. 6 is a block circuit diagram of the conventional LCD, and FIG. 7 is a surface (back surface) opposite to the liquid crystal display panel side in the conventional LCD backlight device. Or a bottom view). As shown in FIG. 5, a liquid crystal display panel 21 in an LCD includes, for example, an array-side substrate 22 formed of a glass substrate or the like on which a large number of pixel portions including thin film transistors (TFTs) are formed, a color filter and a black matrix. It is manufactured by making a color filter side substrate 23 made of a glass substrate or the like formed thereon face each other, adhering these substrates at a predetermined interval, and filling and sealing a liquid crystal between these substrates. In addition, in general, the color filter side substrate 23 applies a vertical electric field applied to the liquid crystal between the pixel electrode and the entire surface of the surface facing the pixel portion including the TFT and the pixel electrode, that is, the liquid crystal side surface. A common electrode for forming is formed. In the case of an IPS (In-Plane Switching) type LCD, this common electrode is formed in the same plane as the pixel electrode in the pixel portion of the array-side substrate 22 to generate a lateral electric field. In the case of an FFS (Fringe Field Switching) type LCD, the common electrode is formed in the pixel portion of the array-side substrate 22 with an insulating layer sandwiched above or below the pixel electrode to generate an edge electric field (Fringe Field). Will be caused.

Further, on the liquid crystal side surface of the color filter side substrate 23, red (R), green (G) and blue (B) color filters corresponding to the respective pixel portions are formed and pass through the respective pixel portions. A black matrix that prevents light from interfering with each other is formed so as to surround the outer periphery of the color filter. An overcoat layer is formed so as to cover the color filter layer, and a common electrode is formed on the overcoat layer. Further, the entire periphery of the liquid crystal side surface of the array side substrate 22 and the entire periphery of the liquid crystal side surface of the color filter side substrate 23 are made of silicone resin, epoxy resin, synthetic rubber or the like. It is adhered and sealed by. Further, in a portion of the surface of the array side substrate 22 on the liquid crystal side that protrudes outward from the color filter side substrate 23, a drive circuit element 26 such as an IC or an LSI as a gate signal line drive circuit or an image signal line drive circuit. Are mounted by a mounting method such as a COG (Chip On Glass) method. The first polarizing plate 24 is arranged on the surface of the liquid crystal display panel 21 on the backlight device 30 side, and the second polarizing plate 25 is arranged on the display side surface.

On the array-side substrate 22 side of the liquid crystal display panel 21, a backlight device 30 having a light emitting element such as an LED (Light Emitting Diode) is arranged with an opening of a resin frame body 42 and a flat plate-shaped portion 42a interposed therebetween. is set up. The flat plate-shaped portion 42 a of the frame body 42 is a flat plate-shaped brim portion formed so as to extend from the inner side surface of the frame body 42 into the gap between the liquid crystal display panel 21 and the backlight device 30. The flat plate-shaped portion 42a of the frame 42 supports the peripheral portion of the surface of the array-side substrate 22 on the backlight device 30 side, and also serves as a spacer for spacing the array-side substrate 22 and the backlight device 30. Also works.

Further, a flat plate portion 51a having an opening in the center overlaps with an end portion of the upper surface (the surface opposite to the liquid crystal side surface) of the color filter side substrate 23 of the liquid crystal display panel 21 from a metal such as Al. There is a front bezel 51 consisting of. The front bezel 51 is an upper frame and is also called a face board. The liquid crystal display panel 21 and the backlight device 30 are protected by a lower frame body (back bezel) 50 made of a metal or alloy such as aluminum (Al) or zinc (Zn) plated steel, and the side of the front bezel 51 is protected. The portion and the side portion of the lower frame body 50 are fixed by means such as screwing or engagement.

Further, the backlight device 30 has a light emitting element 34 such as an LED arranged on its side surface, and the light emitting element 34 is mounted and mounted on a mounting substrate 35 made of a flexible printed circuit (FPC) or the like. There is. Further, the backlight device 30 has a light guide plate 31 made of acrylic resin or the like, and a lens (bead) having a large number of lens-like protrusions or bead-like protrusions on the surface of the light guide plate 31 on the liquid crystal display panel 21 side. An optical sheet 33 as a light reuse sheet including a diffusion sheet and a reflective polarizing film (Dual Brightness Enhancement Film) is placed and fixed. A reflection sheet 32 is arranged on the surface of the light guide plate 31 opposite to the surface on the liquid crystal display panel 21 side. Further, the optical sheet 33 is not arranged at the edge portion of the surface of the light guide plate 31 on the optical sheet 33 side, and instead, the reflection plate 43 for effectively utilizing light is arranged. The backlight device 30 is housed inside a metal container 36. Although the container 36 houses the backlight device 30 in FIG. 5, it may be configured to house the liquid crystal display panel 21 and the backlight device 30.

A circuit in which an electronic element for driving and controlling the backlight device 30 is mounted and a circuit wiring is formed on a surface (outer surface of the bottom) opposite to the surface of the container 36 on the backlight device 30 side. A substrate 40 is arranged. Further, a flexible circuit board 41 composed of an FPC or the like for driving and controlling the drive circuit element 26 is arranged from the outer surface side of the bottom of the container 36 to the drive circuit element 26 via the outer side surface of the frame body 42. Has been done. Further, there is a substantially plate-shaped cover member 52, one end of which is fixed to the lower frame body 50 by means such as screwing and engagement and the other end is fixed by a caulking claw, and the cover member 52 is provided. Are installed to cover the circuit board 40. The cover member 52 is also called a shield cover or a backboard.

Further, FIG. 6 is a block circuit diagram showing a basic configuration of a conventional active matrix type and IPS type LCD. For example, the array-side substrate 77 of the LCD has a plurality of gate signal lines 75 (GL1, GL2, GL3 to GLm) formed in the first direction (for example, the row direction) on the substrate 77 and the first direction. And a plurality of image signal lines 76 (SL1, SL2, SL3 to SLn) formed by intersecting the gate signal line 75 in the second direction (for example, the column direction). In addition, the TFT 71 arranged corresponding to the intersection of the gate signal line 75 and the image signal line 76, the pixel electrodes (PE11, PE12, PE13 to PEmn) connected to the TFT 71, and the pixel electrodes (PE11, PE12, PE13). To PEmn) and a common electrode for forming an electric field such as a lateral electric field applied to the liquid crystal, and a pixel section (P11, P12, P13 to Pmn). Further, it has a common voltage line 72 for supplying a common voltage (Vcom) to the common electrode. In FIG. 6, 73 is a gate signal line drive circuit, 74 is an image signal (source signal) line drive circuit, and 78 is a display section.

Further, as shown in FIG. 7, the conventional LCD backlight device 30 shown in FIG. 5 has the following configuration, for example. A rectangular light guide plate 31, a light emitting element 34 arranged to face the end surface 31p of the light guide plate 31, a mounting substrate 35 on which the light emitting element 34 is mounted, and a main surface 1m of the light guide plate 31, that is, a liquid crystal display panel. The surface (the back surface or the lower surface) opposite to the side surface has a container 36 installed via fixing members 31a and 31b made of a double-sided adhesive tape or the like. The light guide plate 31 has a contact portion 31t for contacting the mounting substrate 35 on the end face 31p, and the fixing members 31a and 31b are two sides s2 adjacent to one side s1 on the end face 31p side of the main surface 1m of the light guide plate 31. , S4 are arranged along the two sides s2, s4 with a length close to the length of the two sides s2, s4. Further, the fixing members 31a and 31b are adhered to the reflecting surface of the reflecting sheet 32, and a surface (rear surface or lower surface) opposite to the reflecting surface of the reflecting sheet 32 is made of the same material as the fixing members 31a and 31b. There are fixing members 32a and 32b that are shaped and arranged and are made of a double-sided adhesive tape or the like. Thereby, the lower surface of the reflection sheet 32 is fixed to the inner bottom surface of the container 36 (see, for example, Patent Document 1).

JP, 2008-9038, A JP 2004-213943 A

However, the conventional backlight device 30 shown in FIGS. 5 to 7 has the following problems as shown in FIGS. 8 to 10. Note that, in FIGS. 8 to 10, the fixing members 31a and 31b are omitted for understanding the working mechanism. As shown in FIG. 8, when the temperature of the backlight device 30 rises to about 50° C. to 60° C., the side s1 of the main surface 31m of the light guide plate 31 is in the dy1 direction, the side s2 is in the dx1 direction, and the side s3. In the direction of dy2 and the side s4 in the direction of dx2 in an attempt to expand. However, since the contact portion 31t on the end surface 31p of the light guide plate 31 abuts the mounting substrate 35, the side s1 cannot move in the direction of dy1 due to expansion. As a result, the side s3 located at a position facing the side s1 moves in the direction of dy2 due to expansion.

Next, since the main surface 31m of the light guide plate 31 contracts when the temperature is lowered to room temperature (about 25° C.) shown in FIG. 9, each side s1 to s4 of the main surface 31m of the light guide plate 31 is a central portion of the main surface 31m. Move towards. Then, as shown in FIG. 10, an interval k1 (shown in FIG. 7) set so that the light of the light emitting element 34 is incident on the end surface 31p of the light guide plate 31 with low reflection and diffused uniformly in the light guide plate 31. , K2, the light of the light emitting element 34 does not enter the end face 31p with low reflection and illuminates the end face 31p and its periphery brightly. As a result, when the display surface of the LCD is viewed, a local bright portion 31r that locally brightens the portion on the light emitting element 34 side is generated, that is, a uniform light emission characteristic of the light guide plate 31 is deteriorated. There was a point.

The above-mentioned problems similarly occur in the backlight device 30 having the fixing members 31a and 31b shown in FIG. It is because the adhesive force of the fixing members 31a and 31b tends to decrease when the temperature of the backlight device 30 rises to about 50° C. to 60° C., so that the fixing members 31a and 31b shown in FIGS. It is considered that this is because the state is close to that when there is no. Further, when the above temperature rises, the adhesive force of the fixing members 31a and 31b is easily retained by the reflection sheet 32 and the container 36 made of polyethylene terephthalate (PET) or the like, but the light guide plate 31 made of acrylic resin or the like is used. On the other hand, the light guide plate 31 is likely to move relatively with respect to the reflection sheet 32 or the container 36 because it is likely to decrease (see, for example, Patent Document 1).

In order to solve the above problems, a configuration in which the fixing member is arranged along the side s1 of the main surface 31m of the light guide plate 31 (for example, see Patent Document 2) is conceivable, but in this configuration, the light emitting element 34 is used. There was a problem that the adhesive strength of the fixing member deteriorates due to the heat of. In addition, when the display surface of the LCD is viewed, if the transparent fixing member is generally near the light emitting element 34, the light reflection characteristic of the main surface 31m on the light reflecting side of the light guide plate 31 is different from that of the portion having the fixing member. There is a problem in that the area with the fixing member looks brighter than the area without the fixing member.

Therefore, the present invention has been completed in view of the above problems, and an object thereof is to change the interval between the light emitting surface of the light emitting element and the end surface of the light guide plate by a temperature cycle of temperature increase and temperature decrease. This is to suppress the deterioration of the uniform light emission characteristics of the light guide plate.

In the backlight device of the present invention, a rectangular light guide plate, a light source arranged to face one end face of the light guide plate, a main surface of the light guide plate is installed via a fixing member, and the light guide plate is provided. A backlight device having a container for accommodating a light plate, the light guide plate having a restricting member for restricting movement of the end surface toward the light source side, and the fixing member is translucent. And at least one edge of two sides adjacent to one side on the end surface side of the main surface is separated from the light source on the side opposite to the one side on the main surface and on the one side side. It is a configuration in which they are unevenly distributed.

In the backlight device of the present invention, preferably, the fixing member is arranged within a range of 1/3 of at least one of the one side and the two sides.

Further, in the backlight device of the present invention, preferably, the fixing member is arranged in a strip shape along at least one of the two sides.

In the backlight device of the present invention, a rectangular light guide plate, a light source arranged to face one end surface of the light guide plate, a main surface of the light guide plate is installed via a fixing member, and the light guide plate is housed. In the backlight device having the container, the end surface of the light guide plate has a restricting member that restricts movement toward the light source side, and the fixing member has a light-transmitting property. At least one edge of two sides adjacent to one side on the end surface side of the main surface is opposite to the one side on the main surface.
Since it is arranged on the opposite side so as to be separated from the light source and unevenly distributed on the one side, the following effects can be obtained. That is, the movement of the light source side portion of the main surface of the light guide plate is restricted by the fixing member when the temperature is decreased in the temperature cycle of temperature increase/decrease, so the distance between the light emitting surface of the light source and the end surface of the light guide plate changes. Can be suppressed. Therefore, it is possible to suppress the deterioration of the uniform light emission characteristics of the light guide plate. It is possible to suppress a decrease in the brightness of the backlight device, and it is also possible to suppress a part where the brightness is decreased near the frame portion of the display unit of the display device. Further, when the fixing member having a light-transmitting property is near the light emitting element, the light reflection characteristic on the main surface of the light guide plate on the light reflecting side changes between the portion with the fixing member and the portion without the fixing member. It is possible to solve the problem that the part looks brighter than the part without the fixing member.

In the backlight device of the present invention, when the fixing member is arranged within the range of one-third to at least one-third of the two sides, at the time of temperature decrease in the temperature increase/decrease temperature cycle. The movement of the portion of the main surface of the light guide plate on the light source side is more easily regulated by the fixing member, so that it is possible to further suppress the change in the distance between the light emitting surface of the light source and the end surface of the light guide plate.

Further, in the backlight device of the present invention, when the fixing member is arranged in a strip shape along at least one of the two sides, the longitudinal direction of the fixing member is parallel to at least one of the two sides. The movement of the light source side portion of the main surface of the light guide plate can be more easily regulated by the fixing member. As a result, it is possible to further prevent the gap between the light emitting surface of the light source and the end surface of the light guide plate from changing. Further, since the fixing member is easily hidden by the frame portion of the display device, it is possible to easily prevent the portion of the fixing member from shining brightly when the display surface is viewed.

FIG. 1 is a diagram showing an example of an embodiment of a backlight device of the present invention, and is a bottom view of a light guide plate and a light emitting element. FIG. 2 is a diagram showing another embodiment of the backlight device of the present invention, and is a bottom view of the light guide plate and the light emitting element. FIGS. 3A, 3B, and 3C are views showing other examples of the embodiments of the backlight device of the present invention, respectively, showing various examples of the fixing member, that is, the light guide plate and the light emitting element. It is a bottom view. FIGS. 4A, 4B, and 4C are views showing other examples of the embodiments of the backlight device of the present invention, respectively, showing various examples of the fixing member, that is, the light guide plate and the light emitting element. It is a bottom view. FIG. 5 is a side sectional view of an example of a conventional liquid crystal display device. FIG. 6 is a block circuit diagram of an example of a conventional liquid crystal display device. FIG. 7 is a bottom view of the conventional liquid crystal display device of FIG. FIG. 8 is a bottom view of the conventional liquid crystal display device of FIG. 5 when the temperature is raised. FIG. 9 is a bottom view of the conventional liquid crystal display device of FIG. 5 when the temperature is lowered. FIG. 10 is a bottom view showing a light guide plate in which uniform light emission characteristics of the conventional liquid crystal display device of FIG. 5 are deteriorated.

Embodiments of a backlight device of the present invention will be described below with reference to the drawings. 1 to 4 show various examples of embodiments of a backlight device of the present invention, and FIGS. 1 and 2 are bottom views of a light guide plate and a light emitting element, respectively, and FIG. 4A to 4C are partial bottom views of the light guide plate and the light emitting element showing various examples of the fixing member. As shown in these drawings, in the backlight device of the present invention, a rectangular light guide plate 1, a light source 34 arranged to face one end face 1 p of the light guide plate 1, and a main surface 1 m of the light guide plate 1. And a container in which the light guide plate 1 is housed and which is installed via the fixing members 1a and 1b, and which restricts movement of the end surface 1p of the light guide plate 1 toward the light source 34 side. The fixing member 1a, 1b has a member and is unevenly distributed on the side of the one side s1 on at least one edge of two sides s2, s4 adjacent to the one side s1 on the end face 1p side of the main surface 1m. It is arranged. It should be noted that, in the example of FIG. 1, the regulating member is a contact portion 1t formed so as to project on the end surface 1p of the light guide plate 1, and the contact portion 1t is in contact with the mounting substrate 35. With the above configuration, the following effects are achieved. That is, when the temperature is decreased in the temperature cycle of temperature increase and temperature decrease, the movement of the portion of the main surface 1m of the light guide plate 1 on the light source 34 side is restricted by the fixing members 1a and 1b. It is possible to suppress a change in the distance k1 between the end face 1p and the end face 1p. Therefore, it is possible to prevent the uniform light emission characteristics of the light guide plate from deteriorating.

The display device using the backlight device of the present invention may be any display device that requires a light source such as an LCD. In the following embodiments, an example in which the display device is an LCD will be described. Further, the LCD having the backlight device of the present invention has the same basic structure as the conventional LCD shown in FIG. 5, and therefore a detailed description of the entire structure will be omitted.

The container 36 in which the backlight device of the present invention is installed is, for example, a box-shaped container such as a housing, but may be a plate-shaped container, or a combination of a plate-shaped container and a frame body. It may be. Further, the container 36 is preferably made of metal such as aluminum (Al) or zinc (Zn) plated steel material, alloy such as stainless steel, etc., because it has good heat dissipation. The part of the container 36 in which the backlight device is installed is the inner bottom surface of the container 36 or the like.

The rectangular light guide plate 1 in the backlight device of the present invention is a flat plate member made of acrylic resin, polycarbonate, or the like, but the light guide plate 1 may be an acrylic resin plate. In this case, the acrylic resin is suitable as the material of the light guide plate 1 because it has excellent durability, high light transmittance of about 93%, high processability, and low cost. When the fixing members 1a and 1b are made of double-sided adhesive tape or the like at the time of temperature rise, there is a characteristic that the adhesive force is likely to decrease, and the conventional problems can be solved by applying the configuration of the present invention. This makes it possible to utilize the advantageous characteristics of the acrylic resin as the light guide plate 1. Further, the light guide plate 1 is not limited to a rectangle or a square, and may have a trapezoidal shape, a parallelogram, a rhombus, or the like.

Further, the light source 34 is a light emitting element such as an LED, an organic electro luminescence (OEL) element, an organic LED (Organic Light Emitting diode: OLED) element, and a semiconductor laser (Laser diode: LD). LEDs are preferable because they are easily obtained and have excellent durability. Further, the light source 34 may be mounted on the mounting board 35, or the mounting board 35 may not be provided.

Further, the backlight device of the present invention has a regulating member that regulates the movement of the end face 1p toward the light source 34 side. However, when the regulating member is the contact portion 1t of the light guide plate 1 shown in FIG. The contact portion 1t may contact the inner surface of the container 36 instead of the mounting substrate 35. When the regulating member is in the container 36, a protrusion such as a protrusion is formed on the inner bottom surface and the inner surface of the container 36, and the protrusion abuts the end surface 1p of the light guide plate 1. May be. Alternatively, the restricting member may be separate from the light guide plate 1 and the container 36.

The fixing members 1a and 1b are, for example, acrylic resin adhesives, polyester adhesives, rubber adhesives, urethane resin adhesives, epoxy resin adhesives, silicone resin adhesives, phenolic resin adhesives, etc. It is composed of one kind or two or more kinds of the adhesive materials. Further, the fixing members 1a and 1b are preferably laminated double-sided adhesive tapes in which the above-mentioned adhesive material layers are formed on both surfaces of a sheet-like base material made of polyester resin. In this case, it becomes easy to bring the thermal expansion coefficients of the fixing members 1a and 1b close to the thermal expansion coefficients of the light guide plate 1 and the reflection sheet 32. The fixing member 1a, 1b is to have a light transmitting property, by Re their, it can be suppressed that the brightness of the backlight device is decreased, also the luminance decreases near the frame portion of the display portion of the display device It is possible to suppress the occurrence of broken parts and the like.

In the example of FIG. 1, the light guide plate 1 has a contact portion 1t that contacts the mounting substrate 35 on the end face 1p. For example, the protruding length of the contact portion 1t from the end surface 1p is about 1.1 mm, and the distance k1 between the light emitting surface 34p of the light source 34 and the end surface 1p of the light guide plate 1 is set to about 0.57 mm. There is. As a result, the light of the light source 34 is incident on the inside of the light guide plate 1 with low reflection from the end surface 1p of the light guide plate 1. The contact portion 1t may be separate from the light guide plate 1.

In the backlight device of the present invention, the fixing member is unevenly distributed on the side of one side s1 on at least one edge of two sides s2 and s4 adjacent to one side s1 on the end face 1p side of the main surface 1m of the light guide plate 1. Are arranged. In the example of FIG. 1, the fixing members 1a and 1b are arranged at each edge of two sides s2 and s4 adjacent to one side s1 on the end face 1p side of the main surface 1m of the light guide plate 1. The fixing member 1a is arranged at the edge of the side s4, which is one of the two sides s2 and s4 adjacent to the one side s1 on the end face 1p side of the main surface 1m of the light guide plate 1, and is fixed to the edge of the side s2. When the member 1b is not arranged, another fixing member may be arranged on the end surface of the light guide plate 1 on the side s2 side of the main surface 1m of the light guide plate 1. In this case, the other fixing members may have the same material, shape, and size as the fixing member 1a in order to make the fixing force the same as that of the fixing member 1a.

The main surface 1m of the light guide plate 1 is, for example, a main surface (light reflecting main surface) opposite to the main surface (light emitting main surface) on the liquid crystal display panel 20 side. Further, the main surface 1m of the light guide plate 1 may be a light emitting main surface. In that case, the container may be a bezel, a frame or the like having a collar portion or the like to which the fixing members 1a and 1b are fixed. Then, as shown in FIG. 1, the fixing members 1a and 1b are preferably arranged in a portion between one side s1 and a center line 1yo connecting the center of the side s2 and the center of the side s4. .. In this case, the movement of the part of the main surface 1m of the light guide plate 1 on the light source 34 side is easily regulated by the fixing members 1a and 1b during the temperature decrease in the temperature cycle of the temperature increase and the temperature decrease. It is possible to further suppress the change in the distance k1 between the end surface 1p of the optical plate 1 and the end surface 1p.

Further, as shown in FIG. 2, the fixing members 1a and 1b are one-third of the length from one side s1 to at least one of the two sides s2 and s4 on which the fixing members 1a and 1b are arranged (line 1ya in FIG. 2). It is preferable to be arranged within the range up to () (the range of L1 in FIG. 2). In this case, the movement of the portion of the main surface 1m of the light guide plate 1 on the light source 34 side is more likely to be restricted by the fixing members 1a and 1b when the temperature is decreased in the temperature cycle of temperature increase and decrease, so that the light emitting surface 34p of the light source 34 and It is possible to further suppress the change in the distance k1 between the light guide plate 1 and the end face 1p. More preferably, the fixing members 1a and 1b are preferably arranged within the range of 1/5 to 1/3 of the length of one side s1 to at least one of the two sides s2 and s4. When it is less than ⅕, the fixing force of the light guide plate 1 to the reflection sheet 32 or the fixing force to the container 36 when the light guide plate 1 is directly installed in the container 36 tends to decrease.

Further, the fixing members 1a and 1b are preferably arranged in a strip shape along at least one of the two sides s2 and s4 on which the fixing members 1a and 1b are arranged. In this case, since the longitudinal directions of the fixing members 1a and 1b are parallel to the directions of the two sides s2 and s4, the fixing members 1a and 1b restrict the movement of the main surface 1m of the light guide plate 1 on the light source 34 side. It will be easier. As a result, it is possible to further suppress the change in the distance k1 between the light emitting surface 34p of the light source 34 and the end surface 1p of the light guide plate 1. Further, since the fixing members 1a and 1b are easily hidden by the frame portion of the display device, it is possible to easily prevent the portions of the fixing members 1a and 1b from shining brightly when the display surface is visually recognized. Also effective. For example, when the lengths of the sides s1 and s3 are about 220 mm and the sides s2 and s4 are about 173 mm on the main surface 1 m of the rectangular light guide plate 1, the lengths of the fixing members 1a and 1b in the lateral direction are set. Is about 2 mm and the length in the longitudinal direction is about 44 mm.

The backlight device of the present invention can employ various suitable forms shown in FIGS. 3(a) to 3(c) and FIGS. 4(a) to 4(c). In these figures, when the fixing member is arranged on the side s2 side, the fixing member is not shown because it has the same configuration as the fixing members 1a1 to 1a6. FIG. 3A shows the square fixing member 1a1. In this case, the fixing force of the fixing member 1a1 acts more locally on the main surface 1m of the light guide plate 1 near the light source 34, so that the fixing member 1a1 does not easily hinder the expansion and contraction of the light guide plate 1. Further, the length of one side of the square fixing member 1a1 is preferably longer than the length of the fixing member 1a in the lateral direction in FIGS. As a result, it is possible to prevent the fixing member 1a1 from having a small area and the fixing force from decreasing.

FIG. 3B shows the circular fixing member 1a2. In this case, the same effect as that of the configuration of FIG. Further, it is preferable that the diameter of the circular fixing member 1a2 is longer than the length of the fixing member 1a in the lateral direction in FIGS. As a result, it is possible to prevent the fixing member 1a2 from having a small area and the fixing force from decreasing.

FIG. 3C shows the elliptical fixing member 1a3. In this case, the same effect as the configuration of FIGS. 3(a) and 3(b) can be obtained. Further, since the area of the fixing member 1a3 is larger than that of the configuration shown in FIGS. 3A and 3B, it is possible to further prevent the fixing force from decreasing. Further, the length of the minor axis of the elliptical fixing member 1a3 is preferably longer than the length of the fixing member 1a in FIGS. As a result, it is possible to further prevent the fixing member 1a3 from having a smaller area and a lower fixing force.

FIG. 4A shows a configuration in which a plurality of strip-shaped fixing members 1a4 are arranged along the side s4. In this case, the fixing force of the fixing member 1a4 can be improved.

FIG. 4B shows a configuration in which a plurality of strip-shaped fixing members 1a5 are arranged along the side s4, and the length of the fixing member 1a5 on the side closer to the center line 1yo is closer to the side s1. It is shorter than the length of 1a5. In this case, the fixing member 1a5 is less likely to hinder the expansion and contraction of the light guide plate 1 as compared with the configuration of FIG.

FIG. 4C shows a configuration in which a plurality of strip-shaped fixing members 1a6 are arranged in the direction of the side s1. In this case, the fixing member 1a6 is less likely to hinder the expansion and contraction of the light guide plate 1 and the fixing force of the fixing member 1a6 is less likely to be reduced, as compared with the configurations of FIGS. Become.

The backlight device of the present invention is not limited to the above-mentioned embodiment, and may be appropriately designed and modified.

The display device having the backlight device of the present invention can be applied to various electronic devices. The electronic devices include car route guidance system (car navigation system), ship route guidance system, aircraft route guidance system, smartphone terminal, mobile phone, tablet terminal, personal digital assistant (PDA), video camera, digital still camera, electronic device. Notebooks, electronic books, electronic dictionaries, personal computers, copiers, terminal devices for game machines, televisions, product display tags, price display tags, industrial programmable display devices, car audio, digital audio players, facsimiles, printers, cash There are automatic teller machines (ATMs), vending machines, medical monitoring devices, digital display watches, and so on.

1 Light guide plate 1a, 1b Fixed member 1m Main surface 1p End surface 1t Contact part 34 Light source 35 Mounting board s1 to s4 Side of main surface 1m

Claims (3)

A rectangular light guide plate,
A light source arranged to face one end surface of the light guide plate;
A backlight device having a main surface of the light guide plate installed via a fixing member and a container in which the light guide plate is housed,
The light guide plate has a regulation member that regulates movement of the end surface toward the light source side,
The fixing member has a light-transmitting property, and at least one edge of two sides adjacent to one side on the end surface side of the main surface is provided with the light source on a side opposite to the one side on the main surface. A backlight device which is spaced apart and unevenly arranged on the one side.
The backlight device according to claim 1, wherein the fixing member is arranged within a range from one side to one-third of the length of at least one of the two sides. The backlight device according to claim 1, wherein the fixing member is arranged in a strip shape along at least one of the two sides.