JP2014010920A - Light source module and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backlight module capable of efficiently reducing light leakage even when a light guide plate is deformed.SOLUTION: A backlight module 10 relating to one embodiment of the present invention includes: a light guide plate 130 that emits light incident from LED groups 104 and 105 provided in LED substrates 102 and 103; a supporting chassis 101; and a bezel 100 that fixes the LED substrates 102 and 103 and the light guide plate 130 to the chassis 101 in the thickness direction of the light guide plate 130. The LED substrates 102 and 103 are arranged in parallel with the light guide plate 130 and the chassis 101.

Description

  The present invention relates to a light source module and a liquid crystal display device including the light source module.

  2. Description of the Related Art Conventionally, in a liquid crystal display device having a liquid crystal display (LCD), a side edge (side light or edge light) that emits light incident on a side surface from a light source in a planar shape is realized in order to realize a thin shape. A backlight having a light guide plate of a type is often used.

  A liquid crystal display device including a liquid crystal panel is suitable for reduction in thickness and weight, and has been used in various fields in recent years. The liquid crystal display device generally includes a light source module called a backlight that irradiates the liquid crystal panel from the back side.

  In recent years, a backlight having a side edge (also referred to as a side light or edge light) type light guide plate that emits light incident on a side surface from a light source into a planar shape in order to realize further thinning of a liquid crystal display device. Is attracting attention. For example, an LED (Light Emitting Diode) is used as the light source of the backlight.

  In such a side-edge type light guide plate, a light source such as an LED is disposed so as to face a side surface (hereinafter also referred to as an incident surface) of the light guide plate, and light is incident from each incident surface of the light guide plate. The incident light propagates while reflecting inside the light guide plate and is emitted from the light exit surface of the light guide plate.

  Examples of the backlight using the light guide plate include a backlight unit described in Patent Document 1. Here, the backlight described in Patent Document 1 will be briefly described with reference to FIG. FIG. 4 is a cross-sectional view schematically illustrating the backlight unit described in Patent Document 1.

  In the backlight unit 50 of Patent Document 1, the LED mounting surface of the LED substrate 502 on which the LED group 504 that is a light source is mounted is disposed so as to face the incident surface 531 that is the side surface in the longitudinal direction of the light guide plate 530. ing. A frame 506 for fixing the LED substrate 502 to the chassis 501 is provided on the back surface of the LED mounting surface of the LED substrate 502.

  The light guide plate 530 propagates the light incident on the incident surface 531 from the LED group 504 and emits the propagated light from the output surface 533 of the light guide plate 530.

JP 2011-243486 A (published on December 1, 2011)

  However, in the backlight unit 50 described in Cited Document 1, when the light guide plate 530 is deformed due to deformation of the chassis 501 or the like due to external stress, thermal stress, or the like, the LED substrate 502 cannot follow the deformation. .

  Here, the relationship between the deformation of the chassis 501 and the displacement of the positional relationship between the light guide plate 530 and the LED substrate 502 will be briefly described.

  The chassis 501 is easily bowed in the thickness direction of the light guide plate 530 or deformed into a wave shape due to external stress or thermal stress. This is because a thin flat member such as a substrate is generally easily bent and deformed in the thickness direction, which is a direction perpendicular to the planar direction, but hardly deformed in the planar direction (so-called in-plane direction). Due to having characteristics.

  The light guide plate 530 is easily bent and deformed in the thickness direction, and since the thickness direction of the light guide plate is oriented in the z direction, which is the bending direction of the chassis 501, the light guide plate 530 is easily deformed following the deformation of the chassis 501. Will do.

  On the other hand, the planar direction of the LED substrate 502 is oriented in the z direction, which is the bending direction of the chassis 201 (that is, the planar direction of the LED substrate 502 is perpendicular to the planar direction of the chassis 501). For this reason, the LED substrate 502 does not deform following the deformation of the chassis 501.

  Further, the light guide plate 530 also has a property of deforming in the thickness direction (z-axis direction) due to moisture absorption and heat. However, since the LED substrate 502 has a characteristic that it is difficult to deform in the z-axis direction as described above, it does not deform following the deformation of the light guide plate 530.

  Therefore, the positional relationship between the light emitting surface of the LED group 504 and the incident surface 531 of the light guide plate 530 is shifted due to deformation of the chassis 501 or deformation of the light guide plate 530 itself, and light emitted from the LED group 504 is incident. It is not optimally incident on the surface 531. As a result, light leakage occurs in the backlight unit 50, causing a reduction in screen quality and a reduction in coupling efficiency due to the light leakage.

  As described above, in the backlight unit described in the cited document 1, the positional relationship between the incident surface 531 and the LED group 504 is appropriately determined by the deformation of the light guide plate 530 due to the deformation of the chassis 501 or the deformation of the light guide plate 530 itself. However, there is a problem that light leakage occurs due to the inability to maintain a proper positional relationship.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a light source module capable of efficiently reducing light leakage even when the light guide plate is deformed. It is in.

  In order to solve the above problems, a light source module according to an aspect of the present invention includes a light source substrate provided with a light source, a light guide plate that emits light incident from the light source from an output surface, the light source substrate, A support chassis that supports the light guide plate; and a fixing unit that fixes the light source substrate and the light guide plate to the support chassis by pressing the light source plate and the light guide plate in the thickness direction of the light guide plate from the light exit surface side. The light source substrate is arranged in parallel to the light guide plate and the support chassis.

  According to said structure, the said light source board | substrate is arrange | positioned in parallel with respect to the said light-guide plate and the said support chassis. Accordingly, when the support chassis is deformed, the light source substrate is deformed according to the deformation of the support chassis together with the light guide plate. Further, when the light guide plate itself is deformed, the support chassis is deformed according to the deformation of the light guide plate, and the light source substrate is deformed according to the deformation of the support chassis.

  Therefore, even when the light guide plate is deformed, the positional relationship between the light guide plate and the light source substrate can be kept substantially constant. That is, the positional relationship between the light source provided on the light source substrate and the light incident surface of the light guide plate can be kept substantially constant even when the light guide plate is deformed.

  Moreover, according to said structure, the said fixing | fixed part has fixed the said light source board | substrate and the said light-guide plate to the said chassis. Thereby, the positional relationship between the light source substrate and the light guide plate can be more efficiently maintained constant. Further, the light guide plate and the light source device can be more efficiently deformed according to the deformation of the support chassis. Furthermore, the support chassis and the light source device can be changed more efficiently according to changes in the light guide plate.

  Accordingly, it is possible to prevent light emitted from the light source from being incident on the light guide plate due to the deformation of the light guide plate, thereby preventing light leakage. Therefore, light leakage can be efficiently reduced. Further, by reducing light leakage, high light coupling efficiency can be maintained, and high screen quality and high light utilization efficiency can be realized. Furthermore, since light leakage can be reduced without providing a special member, cost can also be reduced.

  In the light source module according to one embodiment of the present invention, it is preferable that the light source substrate has flexibility.

  According to said structure, since the said light source board | substrate has flexibility, it is easy to deform | transform. Since the light source substrate is easily deformed in accordance with the deformation of the light guide plate or the support chassis, the positional relationship between the light guide plate and the light source substrate can be efficiently kept substantially constant.

  In the light source module according to one embodiment of the present invention, the light source substrate is preferably a flexible substrate made of polyimide.

  Even if the flexible substrate is deformed, the deterioration of the performance as the substrate is extremely small. Therefore, by using the flexible substrate as the LED substrate 102 as described above, the flexible substrate is not only flexible but also as a substrate against deformation. The reliability can also be increased.

A part on the light source side that is the back surface of the light exiting surface of the light guide plate is a surface on which the light source of the light source substrate is provided and is disposed so as to overlap a part on the light guide plate side,
The fixing portion fixes the light source substrate by pressing the light source substrate to the support chassis side through the light guide plate.
The light source module according to claim 1, wherein the light source module is a light source module.

  According to said structure, a part of said light-guide plate is arrange | positioned so that a part of said light source board may be pinched | interposed with the said support chassis. Moreover, the said fixing | fixed part presses the said light source board to the said fixed chassis via the said light guide plate, and is fixing by pressing the said light guide plate to the said fixed chassis. Thereby, the light guide plate and the light source substrate can be more efficiently fixed.

  In addition, when the light guide plate itself is deformed, the light source substrate is deformed according to the deformation of the light guide plate. Thereby, even when the light guide plate is deformed, the positional relationship between the light guide plate and the light source substrate can be efficiently kept substantially constant. That is, the positional relationship between the light source provided on the light source substrate and the light incident surface of the light guide plate can be efficiently and substantially kept constant even when the light guide plate is deformed.

  Moreover, the light source module which concerns on 1 aspect of this invention WHEREIN: The said light source module is provided with the light absorption part which absorbs the light radiate | emitted from the said light source, The said light-guide plate receives the light radiate | emitted from the said light source. The light source is disposed such that the center position of the light emitting surface of the light source is located closer to the support chassis than the center position of the light receiving surface of the light guide plate, and the light absorbing portion is disposed on the light guide plate. It is preferable that it is arrange | positioned between this light-guide plate and the said support chassis at the light-receiving surface side.

  According to said structure, the said light absorption part can absorb the light leaked between this light guide plate and the said support chassis, without entering into the said light guide plate among the lights radiate | emitted from the said light source. it can. Therefore, the light leaking between the light guide plate and the support chassis is arranged such that the center position of the light emitting surface of the light source is located closer to the support chassis than the center position of the light receiving surface of the light guide plate. Even when the amount of light increases, light leakage can be efficiently reduced. This also makes it possible to increase the screen quality, coupling efficiency, and light utilization efficiency more efficiently.

  Moreover, the light source module which concerns on 1 aspect of this invention WHEREIN: It is preferable that the said light guide plate and the said light source board | substrate are being fixed to the said support chassis via the heat conductive member which has heat conductivity.

  According to said structure, the heat | fever which the said light source emits can be efficiently transmitted to the said support chassis. Accordingly, the support chassis can be efficiently deformed according to deformation of the light guide plate due to heat generation of the light source, and therefore the light source substrate can be efficiently deformed according to deformation of the light guide plate.

  In order to solve the above-described problem, a light source module according to an embodiment of the present invention is a light source substrate provided with a light source, the flexible light source substrate being a flexible substrate made of polyimide, and the above-described A light guide plate that emits light incident from a light source from an output surface, a support chassis that supports the light source substrate and the light guide plate, and the light source substrate and the light guide plate in the thickness direction of the light guide plate from the output surface side. The light source board is a surface on which the light source of the light source board is provided in parallel to the light guide plate and the support chassis. A part of the light guide plate side is disposed on the back surface of the light exiting surface of the light guide plate so as to overlap with a part of the light source side, and the fixing part is configured to pass the light source substrate through the light guide plate. Support above Fixed by pressing the Yashi side, characterized in that.

  According to said structure, the said light source board | substrate is arrange | positioned in parallel with respect to the said light guide plate and the said support chassis, and is arrange | positioned so that it may be pinched | interposed by a part of said light guide plate and the said support chassis. Accordingly, when the support chassis is deformed, the light source substrate is deformed according to the deformation of the support chassis together with the light guide plate. In addition, when the light guide plate itself is deformed, the light source substrate is deformed according to the deformation of the light guide plate.

  Therefore, even when the light guide plate is deformed, the positional relationship between the light guide plate and the light source substrate can be kept substantially constant. That is, the positional relationship between the light source provided on the light source substrate and the light incident surface of the light guide plate can be kept substantially constant even when the light guide plate is deformed.

  Moreover, according to said structure, the said fixing | fixed part presses and fixes the said light source board to the said fixed chassis via the said light guide plate by pressing the said light guide plate to the said fixed chassis. Thereby, the positional relationship between the light source substrate and the light guide plate can be more efficiently maintained constant. Further, the light guide plate and the light source device can be more efficiently deformed according to the deformation of the support chassis. Furthermore, the support chassis and the light source device can be changed more efficiently according to changes in the light guide plate.

  Accordingly, it is possible to prevent light emitted from the light source from being incident on the light guide plate due to the deformation of the light guide plate, thereby preventing light leakage. Therefore, light leakage can be efficiently reduced. Further, by reducing light leakage, high light coupling efficiency can be maintained, and high screen quality and high light utilization efficiency can be realized. Furthermore, since light leakage can be reduced without providing a special member, cost can also be reduced.

  Further, an electronic apparatus including a liquid crystal display device including the light source module is also included in the scope of the present invention.

  In order to solve the above problems, a light source module according to an aspect of the present invention includes a light source substrate provided with a light source, a light guide plate that emits light incident from the light source from an output surface, the light source substrate, A support chassis that supports the light guide plate; and a fixing unit that fixes the light source substrate and the light guide plate to the support chassis in the thickness direction of the light guide plate from the light exit surface side. Are arranged in parallel to the light guide plate and the support chassis.

  According to said structure, even if it is a case where the said light-guide plate deform | transforms, the positional relationship of the said light-guide plate and the said light source board | substrate can be kept substantially constant, and light leakage can be reduced efficiently. .

It is sectional drawing which shows the outline of the arrangement | positioning relationship between the light-guide plate and LED board in the backlight module which concerns on one Embodiment of this invention. It is a disassembled perspective view which shows the outline of a structure of the liquid crystal display device which concerns on one Embodiment of this invention. It is sectional drawing which shows the outline of the arrangement | positioning relationship between the light-guide plate and LED board in the backlight module which concerns on this embodiment. It is sectional drawing which shows the outline of a structure of the backlight unit which concerns on patent document 1. FIG.

<Embodiment 1>
A light source module according to an embodiment of the present invention and an electronic apparatus including the light source module will be described below with reference to FIGS. However, unless otherwise specified, the configuration described in this embodiment is not merely intended to limit the scope of the present invention, but is merely an illustrative example.

  In the present embodiment, a case where the electronic device is realized by a liquid crystal display device and the light source module is realized by a backlight module of the liquid crystal display device will be described as an example. However, the electronic device and the light source module are not limited to this. For example, an indoor lighting device or the like can be given as an example of the electronic device, and a light emitting unit of the lighting device or the like can be given as an example of the light source module.

[Liquid Crystal Display]
First, an outline of the configuration of the liquid crystal display device according to the present embodiment will be described with reference to FIG. FIG. 2 is an exploded perspective view showing an outline of the configuration of the liquid crystal display device 1 according to the present embodiment.

  As shown in FIG. 2, the liquid crystal display device 1 according to the first embodiment of the present invention includes a bezel (fixing portion) 100, a chassis (supporting chassis) 101, LED substrates (light source substrates) 102 and 103, and LED groups (light sources). 104, 105, a reflective sheet 110, heat sinks 112, 113, a light guide plate 130, a laminated sheet group 150, a control unit 160, and a liquid crystal display panel 170.

  Further, as shown in FIG. 2, the above-described components of the liquid crystal display device 1 include a chassis 101, heat sinks 112 and 113, a reflective sheet 110 and LED substrates 102 and 103, a light guide plate 130, a laminated sheet group 150, and a liquid crystal display panel. 170 and the bezel 100 are arranged in this order from the chassis 101 side. The light guide plate 130 and the LED substrate 102 including the LED group 104 and the LED substrate 103 including the LED group 105 are disposed so as to be substantially parallel to each other. The LED substrates 102 and 103 and the liquid crystal display panel 170 are connected to the control unit 160.

  Next, the positional relationship between the light guide plate 130 and the LED substrates 102 and 103 will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing the arrangement relationship between the light guide plate 130 and the LED substrates 102 and 103 in the backlight module 10 according to the present embodiment.

  1 is a cross-sectional view of the backlight module 10 in the longitudinal direction. Here, the arrangement relationship between the light guide plate 130, the LED substrate 102, and the LED group 104 will be mainly described. However, the arrangement relationship between the light guide plate 130, the LED substrate 103, and the LED group 105, which is not illustrated in FIG. The same applies to.

  As shown in FIG. 1, the LED substrate 102 including the LED group 104 is arranged so as to be substantially parallel to an emission surface 133 of a light guide plate 130 described later. The LED group 104 is arranged such that the emitted light is incident on an incident surface (light receiving surface) 131 that is one side surface of the light guide plate 130 in the longitudinal direction.

(Bezel)
The bezel 100 is a housing that protects the liquid crystal display device 1 and covers the liquid crystal display device 1 from the side of the image display surface (that is, covers the liquid crystal display panel 170) as shown in FIG. Is provided. Moreover, the bezel 100 has a window part so that the display area of the liquid crystal display panel 170 can be visually recognized.

  Further, the bezel 100 is fixed so that the light guide plate 130 and the LED substrates 102 and 103 do not float on the bezel 100 side (that is, on the emission surface 133 side of the light guide plate 130). Specifically, the bezel 100 is fixed to the chassis 101 by pressing the light guide plate 130 and the LED substrates 102 and 103 in the thickness direction of the light guide plate 130 from the emission surface 133 side of the light guide plate 130 described later. doing.

  Further, the bezel 100 has a light shielding property and prevents light leakage from a part of the light guide plate 130 covered with the bezel 100. That is, the bezel 100 has a fixing function for fixing the light guide plate 130 and a light blocking function for preventing light leakage. Therefore, since it is not necessary to add a new member for preventing light leakage by using the bezel 100, an increase in cost can be suppressed.

(Chassis)
The chassis 101 is a housing that protects the liquid crystal display device 1 and includes a support portion 101a that supports each component of the liquid crystal display device 1 such as the light guide plate 130 as shown in FIG. The liquid crystal display device 1 is provided so as to cover from the side opposite to the display surface.

  Further, the bezel 100 and the chassis 101 are fixed to each other by a fixing member (not shown), so that each component of the liquid crystal display device 1 positioned between the bezel 100 and the chassis 101 is sandwiched. Accordingly, a part of the end portion of the light guide plate 130 is sandwiched between the bezel 100 and the reflection sheet 110, and the position of the light guide plate 130 in the thickness direction with respect to the LED substrates 102 and 103 (that is, the LED group 104 of the light guide plate 130, The position in the thickness direction with respect to 105) is defined.

(LED group, LED substrate)
The LED substrate 102 includes an LED group 104 including a plurality of LEDs, and the LED substrate 103 includes an LED group 105 including a plurality of LEDs. The LEDs included in the LED groups 104 and 105 are disposed on the LED substrates 102 and 103, respectively, at intervals.

  The LED groups 104 and 105 are arranged so that light is incident on the incident surfaces 131 and 132 that are side surfaces in the longitudinal direction of the light guide plate 130, respectively. The light emitted from the LED group 104 included in the LED substrate 102 is incident on the incident surface 131, and the light emitted from the LED group 105 included in the LED substrate 103 is incident on the incident surface 132 included in the light guide plate 130. Hereinafter, the surface of the LED substrate 102 on which the LED group 104 is provided (mounted) is also referred to as a mounting surface.

  In this embodiment, the case where an LED is used as a light source will be described as an example. However, the present invention is not limited to this, and for example, a configuration using a light source other than an LED such as a fluorescent tube as the light source. May be adopted.

  Moreover, it is preferable to use a flexible material as the material of the LED substrates 102 and 103. Examples of the flexible material include a thin aluminum substrate and a flexible substrate made of polyimide, but are not particularly limited.

(Light guide plate)
As shown in FIG. 1, the light guide plate 130 has incident surfaces 131 and 132, and is emitted from the LED group 104 provided on the LED substrate 102 arranged to face the incident surface 131 on the incident surface 131. Receive light. The light guide plate 130 receives light emitted from the LED group 105 provided on the LED substrate 103 disposed so as to face the incident surface 132 on the incident surface 132.

  In addition, the light guide plate 130 has an exit surface 133. At least one of the exit surface 133 of the light guide plate 130 and the back surface that is the opposite side of the exit surface 133 is a light diffusing section that diffuses incident light and changes the traveling direction of the light in the light guide plate 130 ( (Not shown) is formed.

  The light guide plate 130 propagates the light incident from the incident surfaces 131 and 132 to the inside of the light guide plate 130 while being totally reflected between the emission surface 133 and the back surface and between both side surfaces in the lateral direction. Then, the light total reflection condition is broken in the light diffusion portion mainly formed on the emission surface 133, and light is emitted from the emission surface 133 of the light guide plate 130.

(Reflective sheet)
The reflection sheet 110 is disposed so as to face the surface opposite to the emission surface 133 of the light guide plate 130, reflects light emitted (leaks) from the surface opposite to the emission surface 133, and again reflects the light guide plate. To enter. Further, the reflection sheet 110 has an effect of reflecting the light diffused by the light diffusion portion of the light guide plate 130 and emitting it from the emission surface 133.

  Although the reflection sheet 110 is not necessarily required, the amount of light emitted from the emission surface 133 of the light guide plate 130 can be effectively used because the light absorbed on the chassis 101 side can be effectively used. Can be increased. Accordingly, the reflection sheet 110 can improve the luminance of the liquid crystal display panel 170.

  As described above, the reflection sheet 110 has light reflection characteristics, and examples of the material of the reflection sheet 110 include polyester typified by foamed PET (Polyethylene Terephthalate). There is no particular limitation.

  The reflection sheet 110 may be a sheet that regularly reflects incident light, but it is more preferable to use a sheet that irregularly reflects light. The reflection sheet 110 can reflect light including a reflection component having an angle different from the incident angle by using a sheet on which incident light is irregularly reflected.

(heatsink)
The heat sinks 112 and 113 improve the heat dissipation efficiency of the LED substrates 102 and 103 and the LED groups 104 and 105 by efficiently transferring the heat of the LED substrates 102 and 103 and the LED groups 104 and 105 to the chassis 101.

  Each of the heat sinks 112 and 113 has a thin plate shape, and is disposed in contact with the support portion 101a in parallel.

  In addition, examples of the material of the heat sinks 112 and 113 include aluminum, but are not particularly limited as long as the material has high thermal conductivity. When the material of the chassis 101 is a material having high thermal conductivity such as aluminum, the chassis 101 itself can replace the heat sinks 112 and 113, and the heat sinks 112 and 113 can be omitted.

(Laminated sheet group)
The laminated sheet group 150 has a function of suppressing unevenness in the amount of light emitted from the light guide plate 130 (that is, luminance unevenness) and condensing the light emitted from the light guide plate 130 toward the liquid crystal display panel 170. doing.

  Note that the laminated sheet group 150 is not necessarily required, but by using the laminated sheet group 150, the liquid crystal display panel 170 can be used rather than the case where the light emitted from the light guide plate 130 is directly incident on the liquid crystal display panel 170. The luminance unevenness can be suppressed.

  The laminated sheet group 150 includes, for example, a diffusion sheet, a prism sheet, and a microlens sheet. Note that the number and combination of the sheets constituting the laminated sheet group 150 are not particularly limited as long as the number and combination can provide desired optical performance.

(Control part)
The control unit 160 is a means for comprehensively controlling each unit of the liquid crystal display device 1 and switches ON / OFF of each TFT element (not shown) included in the liquid crystal display panel 170 according to the display timing of the video represented by the video signal. . In addition, the control unit 160 applies a video signal to the liquid crystal display panel 170 to display a video represented by the video signal.

  When the control unit 160 includes a plurality of light guide plates 130, the LEDs included in the LED groups 104 and 105 may be sequentially turned off in synchronization with the application timing of the video signal. Thereby, the control part 160 can provide the period (light emission period) in which light is radiate | emitted from the output surface 133 with which the light-guide plate 130 is equipped in 1 frame period, and the period (non-light emission period) in which light is not radiate | emitted. Therefore, the liquid crystal display panel 170 can alternately perform image display and black display.

(LCD panel)
The liquid crystal display panel 170 includes an active matrix substrate, a color filter, a counter substrate, and liquid crystal sealed between the active matrix substrate and the counter substrate (all not shown). In addition, a plurality of thin film transistor (TFT) elements are formed on the active matrix substrate. The liquid crystal display panel 170 displays an image using light that passes through the laminated sheet group 150 and enters the liquid crystal display panel 170.

[Backlight module]
Next, reduction of light leakage in the backlight module 10 included in the liquid crystal display device 1 according to the present embodiment will be described with reference to FIG.

  FIG. 1 shows the configuration of a part of the backlight module 10 according to the present embodiment (the side on which the LED group 104 of the backlight module 10 is provided), but the part not shown (backlight). The side of the module 10 where the LED group 105 is provided has the same configuration.

  In FIG. 1, the longitudinal direction of the light guide plate 130 is represented by the y axis, and the thickness direction of the light guide plate 130 is represented by the z axis. In FIG. 1, the center of the LED group 104 is the origin of the y-axis and the z-axis (y = 0, z = 0).

  As shown in FIG. 1, the LED substrate 102 including the LED group 104 is disposed on the support portion 101a of the chassis 101 in parallel with the support portion, as described above. The light emission surface of the LED group 104 is disposed so as to face the incident surface 131 of the light guide plate 130.

  Similarly, the light guide plate 130 and the reflection sheet 110 are arranged on the support portion 101a of the chassis 101 in parallel with the support portion 101a.

  Moreover, in the backlight module 10 which concerns on this embodiment, although the case where the light-guide plate 130 is comprised from the one light-guide plate which has a rectangular parallelepiped shape is mentioned as an example, this invention is limited to this. It is not a thing. For example, the light guide plate 130 may have a shape other than a rectangular parallelepiped shape, or may be composed of a plurality of divided light guide plates.

[Positional relationship between LED group and incident surface of light guide plate]
Next, the relationship between the light guide plate 130 and the LED substrate 102 in the backlight module 10 according to the present embodiment will be described with reference to FIG.

  In the backlight module 10 according to the present embodiment, as described above, the LED substrate 102 on which the LED group 104 is mounted is disposed so that the mounting surface thereof is parallel to the support portion 101 a of the light guide plate 101. Yes. In other words, the light guide plate 130, the LED substrate 102, and the support portion 101a of the chassis 101 are arranged in parallel. Therefore, the dimension in the z direction of the substrate can be reduced.

  The light guide plate 130 is in contact with the chassis 101 via the reflection sheet 110 and the heat sink 112, and the LED substrate 102 is in contact with the chassis 101 via the heat sink 112. For this reason, the light guide plate 130 and the LED substrate 102 are easily deformed following the deformation (for example, bowed, wavy, etc.) of the chassis 101 in the z direction.

(Modification of chassis)
First, a case will be described in which the chassis 101 is deformed by an externally applied force (for example, external stress, thermal stress, etc.) (hereinafter also referred to as external force).

  When an external force is applied to the chassis 101, the chassis 101 is deformed in the z-axis direction according to the applied force. At this time, the reflection sheet 110 and the heat sink 112 provided so as to be in contact with the support portion 101 a of the chassis 101 are deformed following the deformation of the chassis 101.

  Furthermore, following the changes of the reflection sheet 110 and the heat sink 112, the light guide plate 130 and the LED substrate 102 provided so as to be in contact with the reflection sheet 110 and the heat sink 112 are also deformed in the z-axis direction. That is, both the light guide plate 130 and the LED substrate 102 are deformed following the deformation of the chassis 101 in the z-axis direction due to an external force.

  Therefore, the positional relationship between the LED group 104 mounted on the LED substrate 102 and the incident surface 131 of the light guide plate 130 is the same even when the light guide plate 130 is deformed by the deformation due to the external force of the chassis 101. Is deformed in accordance with the deformation, so that it is kept substantially constant. In other words, although the light guide plate 130 and the LED substrate 102 are deformed in accordance with the deformation of the chassis 101, the positional relationship is not changed.

  According to the above configuration, in the backlight module 10, even if the light guide plate 130 is deformed by the chassis 101 being deformed by an external force, the positional relationship between the incident surface of the light guide plate 130 and the LED group 104 is shifted. Can be suppressed. Thereby, the backlight module 10 according to the present embodiment can reduce light leakage. Further, by reducing light leakage, high light coupling efficiency can be maintained, and high screen quality and high light utilization efficiency can be realized.

  According to the above configuration, even when the bezel 100 is deformed in addition to the chassis 101 due to an external force, the light guide plate 130 and the LED substrate 102 are in a positional relationship as in the case where the chassis 101 is deformed. Can be kept substantially constant.

(Deformation of light guide plate)
Next, a case where the light guide plate 130 is deformed due to moisture absorption and thermal expansion due to heat generated by the LED group 104 will be described.

  When the light guide plate 130 is deformed in the z-axis direction due to ambient moisture and heat generated by the LED group 104, the light guide plate 130 is provided so as to be in contact with the light guide plate 130, and is provided so as to be in contact with the reflection sheet 110. The heat sink 112 is deformed following the deformation of the light guide plate 130. Further, when the reflection sheet 110 and the heat sink 112 are deformed, the chassis 101 provided so as to be in contact with the reflection sheet 110 and the heat sink 112 is deformed following the deformation of the reflection sheet 110 and the heat sink 112.

  Further, when the heat sink 112 is deformed, the LED substrate 102 provided so as to be in contact with the heat sink 112 is deformed following the deformation of the heat sink 112. That is, the LED substrate 102 changes following the change in the z-axis direction of the light guide plate 130.

  When the heat sink 112 is not provided, the chassis 101 is deformed by the deformation of the reflection sheet 110, and the LED substrate 102 is deformed by the deformation of the chassis 101. As a result, the LED substrate 102 changes following the change in the z-axis direction of the light guide plate 130.

  Therefore, even when the light guide plate 130 is deformed due to moisture absorption and thermal expansion due to heat generation of the LED group 104, the LED group 104 mounted on the LED substrate 102 and the incident surface 131 of the light guide plate 130 The positional relationship is kept substantially constant. That is, since the LED substrate 102 changes according to the change of the light guide plate 130, the positional relationship between the light guide plate 130 and the LED substrate 102 does not change.

  According to the above configuration, the backlight module 10 prevents the positional relationship between the incident surface 131 of the light guide plate 130 and the LED group 104 from being shifted even when the light guide plate 130 itself is deformed. Can do. Thereby, the backlight module 10 according to the present embodiment can reduce light leakage. Further, by reducing light leakage, high coupling efficiency can be maintained, and high screen quality and high light utilization efficiency can be realized.

  In addition, as described above, it is preferable to use a thin aluminum substrate that is a flexible material, a flexible substrate, or the like as the LED substrate 102. According to this, since the LED board 102 has flexibility, when the chassis 101 or the light guide plate 130 is deformed, it can be more easily deformed following the deformation.

  Furthermore, since the performance of the flexible substrate is extremely small even when deformed, the flexible substrate is used as the LED substrate 102, so that the flexible substrate has not only flexibility but also high reliability as a substrate against deformation. Become.

  The deformation of the light guide plate 130 due to moisture absorption and heat, the deformation of the chassis 101 and the bezel 100, and the like repeatedly occur due to changes in the environment around the light guide plate 130 (outside and inside the backlight module 10). Therefore, by using a flexible substrate as the LED substrate 102, it is possible to reduce the deterioration of the LED substrate 102 due to repeated deformation and the failure of the LED substrate 102 (that is, the backlight module 10). .

(Arranged so that part of the LED board and part of the light guide plate overlap)
Further, as shown in FIG. 1, a part of the back surface of the light guide plate 130 near the incident surface 131 is disposed so as to overlap a part of the mounting surface of the LED substrate 102.

  With this arrangement, the LED substrate 102 is sandwiched between the bezel 100 and the chassis 101 via the light guide plate 130 and the heat sink 112. Thereby, the position of the LED group 104 mounted on the LED substrate 102 in the thickness direction of the light guide plate 130 (that is, the position of the light guide plate 130 with respect to the incident surface 131) is more efficiently defined.

  With the above configuration, even if the light guide plate 130 is deformed due to deformation of the chassis 101, the heat sink 112, the bezel 100, and the like due to external force, the light guide plate 130 is directly deformed from the surface in contact with the LED substrate 102 to the LED substrate 102. Can tell.

  Therefore, the LED substrate 102 can be deformed so as to follow the deformation of the light guide plate 130. Similarly, even when the LED substrate 102 is deformed, the deformation of the LED substrate 102 can be directly transmitted to the light guide plate 130 and the light guide plate 130 can be deformed in the same manner as the LED substrate 102.

  Accordingly, the backlight module 10 can keep the positional relationship between the light guide plate 130 and the LED substrate 102 substantially constant.

  Furthermore, even when the light guide plate 130 is deformed due to moisture absorption or thermal expansion, the deformation of the light guide plate 130 can be directly transmitted to the LED substrate 102, and the LED substrate 102 can be deformed in the same manner as the light guide plate 130.

  As shown in FIG. 1, the light guide plate 130 is fixed so as to be sandwiched between the chassis 101 and the bezel 100 via the liquid crystal display panel 170, the laminated sheet group 150, the reflective sheet 110, and the heat sink 112. Further, the LED substrate 102 is fixed so as to be sandwiched between the light guide plate 130 and the heat sink 112. Since the backlight module 10 has such a structure, the light guide plate 130 and the LED substrate 102 are integrated and easily deformed.

  Therefore, the deformation of the LED substrate 102 and the deformation of the light guide plate 130 in the portion where the LED substrate 102 and the light guide plate 130 overlap with each other substantially coincide. As a result, the backlight module 10 according to the present embodiment can suppress misalignment between the incident surface 131 of the light guide plate 130 and the LED group 104 even when the light guide plate 130 is deformed. Can be suppressed. Thereby, the backlight module 10 can increase the screen quality, coupling efficiency, and light utilization efficiency of the liquid crystal display device 1.

  In the prior art, the luminance has been reduced due to a decrease in coupling efficiency. Further, in order to compensate for this decrease in luminance, the current value input to the LED group must be increased, resulting in an increase in power consumption.

  On the other hand, in the backlight module 10 according to the present embodiment, since the coupling efficiency can be increased, it is possible to prevent a decrease in luminance and reduce power consumption.

  As described above, in the backlight module 10 according to this embodiment, the light guide plate 130, the LED substrate 102, and the exit surface 133 of the chassis 101 are arranged in parallel. Thereby, when the light guide plate 30 is deformed by deformation due to external force such as the chassis 101, and when the light guide plate 130 itself is deformed by moisture absorption or heat, the light guide plate 130 and the LED substrate 102 are deformed in the same manner. To do. Therefore, it is possible to suppress the positional deviation between the incident surface 131 of the light guide plate 130 and the LED group 104, and it is possible to effectively reduce light leakage.

  Moreover, the LED groups 104 and 105 are provided so that light may enter the incident surface 131 that is a side surface in the longitudinal direction of the light guide plate 130 (so-called side light emitting LED). Therefore, since the fixing strength between the LED groups 104 and 105 and the LED substrates 102 and 103 can be increased, there is an effect that reliability with respect to an impact such as vibration or dropping is improved.

<Embodiment 2>
Next, another embodiment of the backlight module will be described with reference to FIG. However, unless otherwise specified, the configuration described in this embodiment is not merely intended to limit the scope of the present invention, but is merely an illustrative example.

  The backlight module 20 included in the liquid crystal display device 1 according to the present embodiment will be described with reference to FIG. FIG. 3 is a cross-sectional view schematically showing the arrangement relationship of each member in the backlight module 20 provided in the liquid crystal display device 1 according to the present embodiment. As shown in FIG. 3, the backlight module 20 according to the present embodiment has the same configuration as the backlight module 10 according to the first embodiment, except that the light absorption unit 220 is provided. In the present embodiment, the description of the same configuration as that of the first embodiment is omitted.

(Light absorption part)
The light absorbing unit 220 absorbs the light emitted from the LED group 104 and traveling to the reflection sheet side without being incident on the light guide plate 130. The light absorbing portion 220 may be made of a material having a property of absorbing light (that is, having a low reflectance), and is not particularly limited.

  As shown in FIG. 3, the light absorption unit 220 is disposed so as to be sandwiched between the LED substrate 102 and the reflection sheet 110. Accordingly, the light absorption unit 220 can absorb light incident on the reflection sheet 110 without being incident on the light guide plate 130 out of light emitted from the LED group 104 mounted on the LED substrate 102. .

  The light absorbing unit 220 is disposed so as to be sandwiched between the light guide plate 130 and the heat sink 112. Accordingly, the light absorption unit 220 can transmit the deformation to the light guide plate 130 even when the chassis 101 is deformed by an external force. Even when the light guide plate 130 is deformed due to moisture absorption or heat generation of the LED group 104, the deformation can be transmitted to the chassis 101.

(Positional relationship between LED group and incident surface of light guide plate)
As shown in FIG. 3, in the backlight module 20 according to the present embodiment, the LED group 104 includes a light emitting surface of the LED group 104 whose central position is the central position of the incident surface 131 of the light guide plate 130 (that is, the light guide plate). It is arranged so as to be located closer to the chassis 101 than the center position in the thickness direction of 130.

  Here, as in this embodiment, when the LED group 104 and the incident surface 131 are arranged in parallel so that a part of the LED substrate 102 on which the LED group 104 is mounted and a part of the light guide plate 130 overlap. The positional relationship of is often the above-described positional relationship.

  In this case, among the light emitted from the LED group 104, the light that does not enter the light guide plate 130 has a larger amount of light traveling toward the reflective sheet 110 than the amount of light traveling toward the liquid crystal display panel 170. This increases the amount of light emitted from the LED group 104 that does not enter the light guide plate 130 and enters the gap between the light guide plate 130 and the reflection sheet. It becomes one.

  Even in such a case, by providing the light absorption unit 220 in the backlight module 20, even if the LED group 104 is arranged as described above, it is not efficiently incident on the light guide plate 130. It can absorb light. Therefore, the backlight module 20 according to the present embodiment can reduce light leakage more efficiently. Moreover, since light leakage can be reduced efficiently, screen quality, coupling efficiency, and light utilization efficiency can be increased more efficiently.

  In the above description, as illustrated in FIG. 3, the configuration in which the light absorbing unit 220 is provided without providing the reflective sheet on the LED group 104 side is described as an example, but the present embodiment is limited to this. is not. For example, you may employ | adopt the structure which affixes the light absorption sheet (for example, black tape etc.) which has the property similar to the light absorption part 220 to a part of reflection sheet 110 by the side of the LED group 104. FIG.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention. Further, all modifications within the meaning and scope equivalent to the scope of the claims are included.

  A backlight unit according to one embodiment of the present invention includes a light source module such as a backlight that includes a light source unit that linearly emits light from a light source and emits light in a planar shape by a light guide plate, and the light source module. The present invention can be suitably applied to electronic devices typified by liquid crystal display devices such as television receivers and monitors. Moreover, the backlight module can be suitably applied to an electronic device such as a lighting device as a large planar light source.

1 Liquid crystal display device 10, 20 Backlight module (light source module)
100 bezel (fixed part)
101 Chassis (support chassis)
101a Support part 102, 103 LED substrate (light source substrate)
104, 105 LED group (light source)
110 Reflective sheet 130 Light guide plate 131, 132 Incident surface (light receiving surface)
133 Exit surface 150 Laminated sheet group 160 Control unit 170 Liquid crystal display panel 220 Light absorption unit

Claims (8)

A light source substrate provided with a light source;
A light guide plate that emits light incident from the light source from an exit surface;
A support chassis that supports the light source substrate and the light guide plate;
A fixing part that fixes the light source substrate and the light guide plate to the support chassis by pressing the light source plate and the light guide plate in the thickness direction of the light guide plate from the emission surface side,
The light source substrate is disposed in parallel to the light guide plate and the support chassis.
A light source module characterized by that. The light source substrate has flexibility.
The light source module according to claim 1. The light source substrate is a flexible substrate made of polyimide.
The light source module according to claim 2. A part on the light source side that is the back surface of the light exiting surface of the light guide plate is a surface on which the light source of the light source substrate is provided and is disposed so as to overlap a part on the light guide plate side,
The fixing portion fixes the light source substrate by pressing the light source substrate to the support chassis side through the light guide plate.
The light source module according to claim 1, wherein the light source module is a light source module. The light source module includes a light absorbing portion that absorbs light emitted from the light source,
The light guide plate includes a light receiving surface that receives light emitted from the light source,
The light source is arranged such that the center position of the light emitting surface of the light source is located closer to the support chassis than the center position of the light receiving surface of the light guide plate,
The light absorbing portion is disposed on the light receiving surface side of the light guide plate, between the light guide plate and the support chassis,
The light source module according to claim 1, wherein the light source module is a light source module. The light guide plate and the light source substrate are fixed to the support chassis via a heat conductive member having thermal conductivity.
The light source module according to claim 1, wherein the light source module is a light source module. A light source substrate provided with a light source, which is a flexible substrate made of polyimide, and a flexible light source substrate;
A light guide plate that emits light incident from the light source from an exit surface;
A support chassis that supports the light source substrate and the light guide plate;
A fixing part that fixes the light source substrate and the light guide plate to the support chassis by pressing the light source plate and the light guide plate in the thickness direction of the light guide plate from the emission surface side,
The light source substrate is parallel to the light guide plate and the support chassis, and is a surface of the light source substrate on which the light source is provided, and a part of the light guide plate side is a back surface of the light exit surface of the light guide plate. It is arranged so as to overlap with a part on the light source side,
The fixing portion fixes the light source substrate by pressing the light source substrate to the support chassis side through the light guide plate.
A light source module. The light source module according to claim 1 is provided.
A liquid crystal display device characterized by the above.

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