JP2021082492A - Backlight and liquid crystal display device - Google Patents

Abstract

To provide a backlight that can suppress deformation of a support member for supporting a light source module, and to provide a liquid crystal display device.SOLUTION: A backlight 3 for irradiating liquid crystal cells with light includes: a long-sized light source module 10; and a frame 20 (support member) for supporting the light source module 10. The frame 20 includes a main plate 20a disposed while being opposed to the liquid crystal cells. The main plate 20a includes a projection part 21. The projection part 21 includes a part extending in a direction crossing with at least a longitudinal direction of the light source module 10.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a backlight and a liquid crystal display device.

A liquid crystal display device provided with a liquid crystal display panel can display an image with low power consumption, and is therefore used as a display for various purposes such as a monitor, a television, or a signage. Generally, a liquid crystal display device includes a liquid crystal display panel and a backlight arranged on the back side of the liquid crystal display panel.

The backlight includes a light source, an optical member such as a light guide plate that guides the light emitted from the light source, and a support member such as a frame or a chassis that supports the light source and the optical member. In recent years, a light emitting diode (LED; Light Emitting Diode) has been adopted as a light source of a backlight for reasons such as high efficiency and long life.

Further, the backlight is classified into a direct type and an edge type according to the arrangement of the light source. For example, in a direct type backlight, the light source is arranged directly under the liquid crystal display panel. On the other hand, in the edge type backlight, the light source is arranged on the side of the light guide plate. Specifically, the edge type backlight has a light guide plate arranged on the back side of the liquid crystal display panel and a light source arranged on the side of the end portion of the light guide plate, and emits light from the light source. The structure is such that light enters from the side surface of the end of the light guide plate.

For example, Patent Document 1 discloses an edge-type backlight including a light source module composed of LEDs, a light guide plate that guides light emitted from the light source module, and a frame that supports the light source module and the light guide plate. Has been done.

Japanese Unexamined Patent Publication No. 2012-74349

In a backlight having a frame that supports the light source module, the heat generated by the light source module is conducted to the frame. At this time, the heat of the light source module may cause the frame to warp and deform the frame. In particular, since the backlight used in the liquid crystal display device for medical applications has high brightness, the heat generated by the light source module becomes high, so that the frame is liable to warp.

Such deformation of the frame will be specifically described with reference to FIGS. 11 and 12. FIG. 11 is a diagram schematically showing an example of a frame 20X used for a backlight and a light source module 10X attached to the frame 20X. FIG. 12 is a diagram for explaining how the frame 20X is deformed by the heat generated by the light source module 10X, and shows a state when the frame 20X of FIG. 11 is viewed from below. Further, in FIG. 12, the broken line indicates the frame 20X in the initial state, and the solid line indicates the frame 20X after the deformation. The points P1 to P4 of the side plate 20b in FIG. 11 correspond to the points P1 to P4 of the side plate 20b in FIG.

As shown in FIG. 11, the frame 20X has a main plate 20a having a rectangular plan view shape and four side plates 20b standing on four sides of the main plate 20a. The light source module 10X includes a long substrate 11X and a plurality of light emitting elements 12X mounted on the substrate 11X along the longitudinal direction of the substrate 11X. The light emitting element 12X is, for example, an LED light source.

In FIG. 11, the light source module 10X is attached to one side plate 20b of the frame 20X. Specifically, the substrate 11X of the light source module 10X is attached and fixed to the inner surface of one side plate 20b erected on the long side of the main plate 20a.

In this case, when the light source module 10X emits light and generates heat, the substrate 11X of the light source module 10X thermally expands and extends in the longitudinal direction of the substrate 11X as shown by the arrow in FIG. At this time, since the front edge of the side plate 20b of the frame 20X is the open edge of the frame 20X, the force for restricting deformation does not act on the front edge of the side plate 20b. Therefore, the front edge of the side plate 20b is easily deformed. On the other hand, since the rear edge of the side plate 20b of the frame 20X is a connecting portion with the main plate 20a of the frame 20X, a force for restricting deformation acts on the rear edge of the side plate 20b. Therefore, the rear edge of the side plate 20b is not deformed as much as the front edge of the side plate 20b. As a result, as shown in FIG. 12, the frame 20X is deformed so as to be twisted backward due to the stress caused by the expansion of the light source module 10.

When the frame of the backlight is deformed in this way, the image quality of the display image displayed on the liquid crystal display device deteriorates. For example, in a liquid crystal display device using a transverse electric field type liquid crystal display panel such as an IPS (In Plane Switching) panel as a liquid crystal display panel, when a black image is displayed, if the frame of the backlight is deformed, the liquid crystal display panel The shading rate decreases, the displayed image becomes whitish, and the contrast decreases.

The present disclosure has been made in order to solve such a problem, and an object of the present invention is to provide a backlight and a liquid crystal display device capable of suppressing deformation of a support member that supports a light source module.

One aspect of the backlight according to the present disclosure is a backlight that irradiates a liquid crystal cell with light, and includes a long light source module and a support member that supports the light source module, and the support member is a liquid crystal display. It has a main plate that is arranged to face the cell, the main plate having a protrusion, and the protrusion having a portion extending at least in a direction intersecting the longitudinal direction of the light source module.

One aspect of the liquid crystal display device according to the present disclosure includes the above-mentioned backlight and a liquid crystal cell arranged on the light emitting side of the backlight.

According to the present disclosure, it is possible to suppress deformation of the support member that supports the light source module.

It is a perspective view of the liquid crystal display device which concerns on embodiment. It is a top view of the liquid crystal display device which concerns on embodiment. It is sectional drawing of the liquid crystal display device which concerns on embodiment in line III-III of FIG. FIG. 3 is an enlarged cross-sectional view of the liquid crystal display device according to the embodiment on the left side portion of FIG. It is a perspective view when the frame in the backlight which concerns on embodiment is seen from the front side. , It is a perspective view when the frame in the backlight which concerns on embodiment is seen from the rear side. It is a partially enlarged view which enlarges and shows a part of the frame in the backlight which concerns on embodiment. FIG. 5 is an enlarged cross-sectional view showing a part of a frame of a backlight used in the liquid crystal display device according to the first modification. It is a perspective view when the frame of the backlight used for the liquid crystal display device which concerns on modification 2 is seen from the rear side. It is a partially enlarged view which shows the part of the frame which concerns on the modification 2 in an enlarged manner. It is a figure which shows an example of a frame used for a backlight and a light source module attached to a frame schematically. It is a figure for demonstrating how the frame is deformed by the heat generated by a light source module.

Hereinafter, embodiments of the present disclosure will be described. It should be noted that all of the embodiments described below show a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, the arrangement positions of the components, the connection form, and the like shown in the following embodiments are examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, the components not described in the independent claims are described as arbitrary components.

Each figure is a schematic view and is not necessarily exactly illustrated. Therefore, the scales and the like do not always match in each figure. In each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description will be omitted or simplified.

Further, in the present specification and drawings, the X-axis, the Y-axis, and the Z-axis represent the three axes of the three-dimensional Cartesian coordinate system. Therefore, the X-axis and the Y-axis are orthogonal to each other and both are orthogonal to the Z-axis. In the following embodiments, the positive direction of the Z-axis is the front and the negative direction of the Z-axis is the rear.

(Embodiment)
First, the configuration of the liquid crystal display device 1 according to the embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a perspective view of the liquid crystal display device 1 according to the embodiment. FIG. 2 is a plan view of the liquid crystal display device 1. FIG. 3 is a cross-sectional view of the liquid crystal display device 1 taken along the line III-III of FIG. FIG. 4 is an enlarged cross-sectional view of the liquid crystal display device 1 on the left side portion of FIG.

As shown in FIGS. 1 to 4, the liquid crystal display device 1 includes a liquid crystal display panel 2 and a backlight 3.

As shown in FIGS. 3 and 4, the liquid crystal display panel 2 is arranged on the light emitting side of the backlight 3. The liquid crystal display panel 2 displays a color image or a monochrome image. In the present embodiment, the liquid crystal display panel 2 displays a color image.

The liquid crystal display panel 2 has a liquid crystal cell and a pair of polarizing plates attached to both sides of the liquid crystal cell. A liquid crystal cell is a liquid crystal panel on which an image is displayed on a front display surface. The liquid crystal cell has, for example, a pair of transparent substrates and a liquid crystal layer sealed between the pair of transparent substrates. The pair of polarizing plates are attached to the outer surfaces of the pair of transparent substrates of the liquid crystal cell. The pair of polarizing plates are arranged so that the polarization directions are orthogonal to each other. That is, the pair of polarizing plates have a cross Nicol arrangement.

As the pair of transparent substrates, a glass substrate, a transparent resin substrate, or the like can be used. Further, the liquid crystal material of the liquid crystal layer can be appropriately selected according to the driving method of the liquid crystal cell. The drive method of the liquid crystal cell is, for example, a transverse electric field method such as an IPS (In Plane Switching) method or an FFS (Fringe Field Switching) method, but a VA (Vertical Alignment) method or a TN (Twisted Nematic) method may also be used. Good.

The transparent substrate on the backlight 3 side (rear side) of the pair of transparent substrates is a TFT substrate having a thin film transistor (TFT) provided corresponding to each of a plurality of pixels arranged in a matrix. Is. Further, the transparent substrate on the display surface side (front side) of the pair of transparent substrates is a facing substrate facing the TFT substrate. A color filter (CF; Color Filter) and a black matrix are formed on the facing substrate.

A plurality of video signal lines and a plurality of scanning signal lines are formed orthogonal to each other on the TFT substrate. The scanning signal line is provided for each horizontal row of pixels, for example, and is connected to the gate electrode of the TFT of each pixel. The video signal line is provided for each vertical row of pixels, for example, and is connected to the source electrode of the TFT of each pixel. Further, a pixel electrode formed in each pixel is connected to the drain electrode of the TFT of each pixel.

The TFT of each pixel is on / off controlled in units of horizontal columns according to the scanning signal applied to the gate electrode via the scanning signal line. When the TFT is turned on, data voltage is supplied to the pixel electrodes corresponding to the TFT from the video signal line connected to the TFT. Then, an electric field is generated in the liquid crystal layer due to the difference between the data voltage supplied to the pixel electrodes and the common voltage supplied to the common electrodes. This electric field changes the orientation of the liquid crystal molecules in the liquid crystal layer in each pixel, and the transmittance of the light incident on the liquid crystal display panel 2 from the backlight 3 changes, so that a desired image can be displayed in the image display area of the liquid crystal display panel 2. Is displayed.

The backlight 3 is arranged so as to face the liquid crystal display panel 2. Therefore, the backlight 3 and the liquid crystal cell of the liquid crystal display panel 2 face each other. Specifically, the backlight 3 is arranged on the back side of the liquid crystal display panel 2 and irradiates the liquid crystal display panel 2 with light. For example, the backlight 3 irradiates the liquid crystal display panel 2 with white light as illumination light. The backlight 3 is a surface light source, and irradiates the liquid crystal display panel 2 with diffused light having a high degree of uniformity.

In the present embodiment, the backlight 3 is a backlight unit composed of a plurality of members. Specifically, the backlight 3 includes a light source module 10, a frame 20, and an optical member 30.

Further, the backlight 3 is an LED backlight that uses an LED as a light source. Therefore, the light source module 10 is an LED module composed of LEDs. The light source module 10 emits white light as the illumination light of the backlight 3.

The frame 20 is a support member that supports the light source module 10. The frame 20 also supports the optical member 30. In the present embodiment, the frame 20 is a rear frame (lower frame) located behind the liquid crystal display panel 2. The frame 20 is made of a metal material such as iron or aluminum. Further, the frame 20 may be made of a metal plate having high rigidity such as a steel plate or an aluminum plate. In the present embodiment, the frame 20 is made of an aluminum plate. The detailed structure of the frame 20 will be described later.

The optical member 30 is a member that imparts an optical action to the light of the light source module 10. The optical member 30 includes a light guide plate 31, a reflector 32, and a diffuser 33.

The light guide plate 31 is a light guide member that guides the light emitted from the light source module 10. Specifically, the light guide plate 31 guides the light incident from the end of the light guide plate 31 and emits it from the front surface of the light guide plate 31. The light guide plate 31 is a light incident surface 31a (light incident surface) on which the light emitted from the light source module 10 is incident, and a surface on which the light incident on the light guide plate 31 is emitted from the inside of the light guide plate 31 to the outside. It has a light emitting surface 31b (light emitting surface) and a back surface 31c which is a surface facing the light emitting surface. In the present embodiment, the end surface (side surface) of the end portion of the light guide plate 31 is the light incoming surface 31a, the front surface of the light guide plate 31 is the light emitting surface 31b, and the back surface of the light guide plate 31 is the back surface 31c. The light guide plate 31 is, for example, a light guide sheet made of a translucent resin material.

The reflector 32 is a reflecting member that reflects the light emitted from the light source module 10. Specifically, the reflector 32 is arranged on the back surface side of the light guide plate 31, and reflects the light of the light source module 10 that is incident on the light guide plate 31 and emitted from the back surface 31c of the light guide plate 31, and the light guide plate 31. It is emitted from the light emitting surface 31b of. In the present embodiment, the reflector 32 is in contact with the back surface 31c of the light guide plate 31. The reflector 32 is, for example, a reflector made of a white resin material, a metal plate, or the like.

The diffuser plate 33 is a diffuser member that diffuses (scatters) the light emitted from the light source module 10. Specifically, the diffuser plate 33 diffuses the light of the light source module 10 emitted from the front surface of the light guide plate 31. The diffusing plate 33 is, for example, a diffusing sheet in which a light diffusing material is dispersed in a translucent resin material.

The optical member 30 may include other functional sheets such as a prism sheet. The functional sheet may be inserted between two of the light guide plate 31, the reflector 32 and the diffuser plate 33, or may be arranged on the front side of the diffuser plate 33, for example.

In the present embodiment, the backlight 3 is an LED backlight using an LED as a light source. Therefore, the light source module 10 is an LED module composed of LEDs.

The light source module 10 has an elongated shape. Specifically, the light source module 10 has a long substrate 11 and a plurality of light emitting elements 12 mounted on the substrate 11 along the longitudinal direction of the substrate 11. The plurality of light emitting elements 12 are mounted in a straight line, for example.

The light source module 10 is arranged so as to face the light incoming surface 31a of the light guide plate 31. In the present embodiment, the backlight 3 is an edge type backlight. Therefore, the light source module 10 is arranged on the side of the optical member 30. Specifically, the light source module 10 is arranged on the side of the end portion of the light guide plate 31. More specifically, the light source module 10 is arranged so that the light emitting surface of the light emitting element 12 faces the side end surface (light entering surface 31a) of the light guide plate 31. As a result, the light emitted from the light source module 10 enters the light guide plate 13 from the lateral end of the light guide plate 13.

The substrate 11 is a mounting substrate for mounting the light emitting element 12. Specifically, the substrate 11 is a wiring board in which wiring is patterned. As the substrate 11, a resin substrate, an insulating coated metal substrate, a ceramic substrate, or the like can be used.

Each of the light emitting elements 12 is an LED light source composed of LEDs. In the present embodiment, the light emitting element 12 is a white LED light source that emits white light. The white light emitted from the light emitting element 12 is incident on the inside of the light guide plate 31 from the side surface (end face) of the light guide plate 31.

As an example, the light emitting element 12 is a surface mount device (SMD) type LED element that is individually packaged. Specifically, the light emitting element 12 includes a white resin package (container) having a recess, an LED chip (bare chip) primarily mounted on the bottom surface of the recess of the package, and a seal sealed in the recess of the package. It has a member. The sealing member is made of a translucent resin material such as a silicone resin. In this case, the LED chip is a blue LED chip that emits blue light when energized, and the sealing member filled in the container is a silicone resin containing a yellow phosphor (fluorescent resin). Can be used.

The light emitting element 12 itself may be an LED element which is an LED chip (bare chip). In this case, the light source module 10 has a COB (Chip On Board) structure in which the LED chip (light emitting element 12) is directly mounted on the substrate 11. In this case, the plurality of light emitting elements 12 mounted on the substrate 11 may be collectively or individually sealed by the sealing member.

Further, the liquid crystal display device 1 includes a front frame 50 (upper frame) and a middle frame 60 (middle frame) in addition to the frame 20 which is a rear frame.

The front frame 50 is located in front of the liquid crystal display panel 2, and has a bezel portion that covers the front of the peripheral portion of the liquid crystal display panel and a side wall portion that is located on the side of the liquid crystal display panel 2 and the backlight 3. The front frame 50 is, for example, a metal frame having a rectangular frame shape in a plan view and an L-shaped cross section, and is made of a metal member having high rigidity such as a steel plate or an aluminum plate.

The middle frame 60 is arranged between the lower frame 20 and the front frame 50. The middle frame 60 supports the liquid crystal display panel 2 from the backlight 3 side. As the middle frame 60, a mold frame formed by molding a synthetic resin can be used. The material of the middle frame 60 is not limited to the resin material, but may be a metal material. In the present embodiment, the middle frame 60 has a side wall portion and a protruding portion protruding inward from the side wall portion. The outer peripheral end portion of the liquid crystal display panel 2 is located between the protruding portion of the middle frame 60 and the bezel portion of the front frame 50.

The liquid crystal display panel 2 is connected to the circuit board 70 via the flexible wiring board 71. The circuit board 70 is a printed circuit board (PCB; Printed Circuit Board) having a substantially rectangular plate shape. Although not shown, a plurality of electronic components are mounted on the circuit board 70. The circuit board 70 is covered with a circuit cover 80.

Next, the detailed structure of the frame 20 will be described with reference to FIGS. 3 and 4, with reference to FIGS. 5 to 7. FIG. 5 is a perspective view of the frame 20 of the backlight 3 according to the embodiment when viewed from the front side. FIG. 6 is a perspective view of the frame 20 when viewed from the rear side. FIG. 7 is a partially enlarged view showing a part of the frame 20 in an enlarged manner. Note that FIGS. 5 to 7 show the electric wire 90 connected to the light source module 10, and the light source module 10 to which the electric wire 90 is connected is not shown.

As shown in FIGS. 3 to 7, the frame 20 has a main plate 20a and a side plate 20b. As shown in FIG. 5, the frame 20 has a thin box shape with the main plate 20a as the bottom plate and the side plates 20b as the side walls. The box-shaped frame 20 has an opening at the front.

As shown in FIGS. 3 and 4, the main plate 20a is arranged so as to face the liquid crystal display panel 2. Specifically, the main plate 20a is arranged so as to face the liquid crystal cell of the liquid crystal display panel 2. In the present embodiment, the plan view shape of the main plate 20a is a substantially rectangular shape having four sides, similarly to the liquid crystal display panel 2. Further, the main plate 20a faces the optical member 30. Specifically, the main plate 20a faces the back surface 31c of the light guide plate 31, the back surface of the reflector 32, and the back surface of the diffusion plate 33. Further, the main plate 20a supports the optical member 30. That is, the main plate 20a supports the light guide plate 31, the reflection plate 32, and the diffusion plate 33. In the present embodiment, the main plate 20a is in contact with the reflector 32 of the optical member 30. The reflector 32 is supported by the main plate 20a at a portion other than the protrusion 21 described later.

The side plate 20b is erected on one side of the main plate 20a and extends along the one side. In the present embodiment, the side plates 20b are provided on each of the four sides of the main plate 20a. Specifically, the side plate 20b corresponds to each of the four sides of the main plate 20a.

The side plate 20b is composed of a first side plate 20b1, a second side plate 20b2, a third side plate 20b3, and a fourth side plate 20b4. The first side plate 20b1 is erected on the first long side of the main plate 20a and extends along the first long side. The second side plate 20b2 is erected on the second long side of the main plate 20a and extends along the second long side. The third side plate 20b3 is erected on the first short side of the main plate 20a and extends along the first short side. The fourth side plate 20b4 is erected on the second short side of the main plate 20a and extends along the second short side. The first side plate 20b1, the second side plate 20b2, the third side plate 20b3, and the fourth side plate 20b4 form a rectangular frame.

The first side plate 20b1, the second side plate 20b2, the third side plate 20b3, and the fourth side plate 20b4 are adjacent to each other at the end in the longitudinal direction. Each of the 20b3 and the fourth side plate 20b4 has its longitudinal ends not connected to each other, but may be connected.

The side plate 20b faces the light guide plate 31. The light source module 10 is attached to the inner surface of the side plate 20b. The light source module 10 may be attached to any one of the first side plate 20b1, the second side plate 20b2, the third side plate 20b3, and the fourth side plate 20b4. In the present embodiment, the light source module 10 is attached to the first side plate 20b1 corresponding to the first long side and the second side plate 20b2 corresponding to the second long side. Specifically, two light source modules 10 arranged in the longitudinal direction of each of the first side plate 20b1 and the second side plate 20b are attached to each of the first side plate 20b1 and the second side plate 20b2.

Further, the light source module 10 is attached to the side plate 20b by the adhesive member 40. As an example, the adhesive member 40 is a double-sided tape, and the substrate 11 and the side plate 20b of the light source module 10 are bonded by the double-sided tape. As a result, the light source module 10 is fixed to the side plate 20b. The fixing means between the light source module 10 and the side plate 20b is not limited to the double-sided tape. For example, a heat conductive sheet having adhesiveness as an adhesive member 40 may be inserted between the light source module 10 and the side plate 20b. As a result, the light source module 10 and the side plate 20b can be brought into close contact with each other, so that the heat generated by the light source module 10 can be efficiently conducted to the frame 20.

The main plate 20a has a protruding portion 21. The protrusion 21 can be formed by performing a press working such as drawing on a metal plate having a constant thickness that constitutes the frame 20. Specifically, the protruding portion 21 is a drawing-shaped drawing portion formed by drawing. Therefore, the plate thickness of the main plate 20a in the protruding portion 21 is constant, and the recessed portion is formed by the protruding portion 21. That is, the protruding portion 21 is both convex and concave.

The protrusion 21 has a portion extending at least in a direction intersecting the longitudinal direction of the light source module 10. In the present embodiment, the projecting portion 21 has a first extending portion 21a and a second extending portion 21b as portions extending in a direction intersecting the longitudinal direction of the light source module 10.

As shown in FIG. 5, the first extending portion 21a is formed in a convex shape so as to extend in the first direction d1 intersecting the longitudinal direction of the light source module 10. The second extending portion 21b is formed in a convex shape so as to extend in the second direction d2 intersecting the longitudinal direction of the light source module 10. The first direction in which the first extending portion 21a extends and the second direction in which the second extending portion 21b extends are different from each other, and the first extending portion 21a and the second extending portion 21b Are crossing. In the present embodiment, both the first extending portion 21a and the second extending portion 21b are formed in a straight line, and the length of the first extending portion 21a and the length of the second extending portion 21b Is almost the same. Therefore, the first extending portion 21a and the second extending portion 21b are formed in a substantially X shape in a plan view. The first extending portion 21a and the second extending portion 21b do not intersect (that is, orthogonally) at 90 degrees, but may intersect at 90 degrees.

Further, each of both ends of the first extending portion 21a in the longitudinal direction and each of both ends of the second extending portion 21b in the longitudinal direction are located at the ends of the main plate 20a. Specifically, one end in the longitudinal direction of the first extending portion 21a and one end in the longitudinal direction of the second extending portion 21b are located at the end of the first long side of the main plate 20a. The other end of the first extending portion 21a in the longitudinal direction and the other end of the second extending portion 21b in the longitudinal direction are located at the end of the second long side of the main plate 20a. ..

In the present embodiment, the longitudinal ends of the first extending portion 21a and the second extending portion 21b are located at positions recessed from the edge of the short side of the main plate 20a. Therefore, one end of the first extending portion 21a in the longitudinal direction is located at a position recessed from the edge of the first short side of the main plate 20a at the end of the first long side of the main plate 20a. 1 The other end of the extending portion 21a in the longitudinal direction is located at the end of the second long side of the main plate 20a at a position recessed from the end edge of the second short side of the main plate 20a. Further, one end of the second extending portion 21b in the longitudinal direction is located at a position recessed from the end edge of the second short side of the main plate 20a at the end of the first long side of the main plate 20a. 2. The other end of the extending portion 21b in the longitudinal direction is located at the end of the second long side of the main plate 20a at a position recessed from the end edge of the first short side of the main plate 20a.

The protruding portion 21 further has a third extending portion 21c. The third extending portion 21c extends over the entire circumference of the end portion of the main plate 20a. That is, the third extending portion 21c is formed in a substantially rectangular frame shape (frame shape) in a plan view. Further, the third extending portion 21c is formed in a convex shape.

In the present embodiment, the protruding portion 21 projects toward the side opposite to the liquid crystal cell side. Specifically, the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c all project toward the side opposite to the liquid crystal cell side. That is, the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c project in a direction away from the liquid crystal display panel 2. With this configuration, the frame 20 does not contact the optical member 30 with the portion where the protrusion 21 is formed, and supports the optical member 30 at the portion where the protrusion 21 of the main plate 20a is not formed. As a result, an air layer exists between the protrusion 21 and the optical member 30 (reflector 32).

The first extending portion 21a, the second extending portion 21b, and the third extending portion 21c can be formed at the same time by drawing. In this case, the protrusion amounts (drawing depths) of the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c are the same as each other. Therefore, the outer and inner surfaces of the protruding portions of the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c are flush with each other. Further, the widths of the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c are the same as each other.

When the screen size of the liquid crystal display device 1 is 24 inches, the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c have, for example, a protrusion amount (throttle depth) of 2 mm or more. It is about 10 mm and has a width of 10 mm to 40 mm.

Further, in the present embodiment, both ends in the longitudinal direction of the first extending portion 21a and both ends in the longitudinal direction of the second extending portion 21b are connected to the third extending portion 21c. Specifically, the first extending portion 21a and the second extending portion 21b are formed in succession with the third extending portion 21c.

As shown in FIGS. 6 and 7, the protruding portion 21 is provided with a recessed portion 22 in which a part of the electric wire 90 is arranged. The recessed portion 22 is provided at a position where the electric wire 90 crosses the protruding portion 21. The recessed portion 22 is a stepped portion formed in a stepped shape. The amount of protrusion of the recessed portion 22 is smaller than that of the portion of the recessed portion 21 other than the recessed portion 22. That is, in the portion where the recessed portion 22 is provided, the depth of the drawing of the protruding portion 21 is shallow.

The recessed portion 22 is provided in each of the first extending portion 21a and the second extending portion 21b. In the present embodiment, since the electric wires 90 are connected to each of the four light source modules 10, four electric wires 90 are used. Therefore, the recessed portions 22 are provided at four positions of the protruding portions 21. Specifically, two recessed portions 22 are provided in each of the first extending portion 21a and the second extending portion 21b.

The electric wire 90 is a power line for supplying power to the light source module 10. One end of the electric wire 90 is connected to a connector portion provided on the substrate 11 of the light source module 10, and the other end portion of the electric wire 90 is connected to a connector portion provided in a power supply circuit (not shown). .. As a result, electric power for causing the light emitting element 12 to emit light can be supplied to the light source module 10. Although connector terminals are provided at both ends of the electric wire 90, in FIG. 6, the connector terminals at the end of the electric wire 90 on the power supply circuit side are shown, but the end of the electric wire 90 on the light source module 10 side. Connector terminals are not shown.

Further, the protruding portion 21 is provided with a through hole 23 through which the electric wire 90 is inserted. The through hole 23 is provided in the vicinity of the light source module 10. Specifically, the through hole 23 is provided in the third extending portion 21c. By providing the through hole 23 in the protruding portion 21, the electric wire 90 routed to the back side of the frame 20 can be inserted into the through hole 23 and pulled out to the front side of the frame 20 to be connected to the light source module 10.

As described above, in the liquid crystal display device 1 and the backlight 3 according to the present embodiment, the main plate 20a of the frame 20 supporting the light source module 10 has a protrusion extending at least in a direction intersecting the longitudinal direction of the light source module 10. It has a part 21.

With this configuration, the protruding portion 21 functions as a reinforcing rib of the main plate 20a, so that the rigidity of the frame 20 can be improved. As a result, even if the light source module 10 expands due to the heat generated by the light source module 10 and stress is applied to the frame 20, the frame 20 can be prevented from warping. That is, by providing the protruding portion 21, the strength against the warp generated in the frame 20 can be improved. Therefore, even if stress is applied to the frame 20 due to the expansion of the light source module 10, it is possible to suppress the deformation of the frame 20. As a result, it is possible to prevent the frame 20 from being deformed and the image quality of the display image displayed on the liquid crystal display device 1 from being deteriorated.

In particular, in a liquid crystal display device using a horizontal electric field type liquid crystal display panel such as an IPS panel, it is necessary to reduce warpage or unevenness of peripheral members of the liquid crystal display panel 2 in order to suppress assembly unevenness due to stress. That is, in a liquid crystal display device using a horizontal electric field type liquid crystal display panel, when the frame is deformed, assembly unevenness occurs and the image quality of the displayed image tends to deteriorate. On the other hand, by using the backlight 3 in the present embodiment, it is possible to effectively suppress the deformation of the frame 20, so that a transverse electric field type liquid crystal display panel such as an IPS panel is used as the liquid crystal display panel 2. Even if there is, it is possible to effectively suppress the deterioration of the image quality of the displayed image.

Further, the backlight 3 according to the present embodiment can effectively suppress the warp of the frame 20 even if the heat generated by the light source module 10 becomes high, so that the heat generated by the light source module 10 can be effectively suppressed. Is particularly suitable for high brightness backlights where the temperature is high. That is, even if the backlight 3 is compatible with high brightness, it is possible to effectively suppress the deformation of the frame 20 due to the expansion of the light source module 10.

Further, in the present embodiment, the protruding portion 21 of the frame 20 intersects the first extending portion 21a extending in the first direction intersecting the longitudinal direction of the light source module 10 with the longitudinal direction of the light source module 10. It has a second extending portion 21b that extends in the second direction and intersects the first extending portion 21a.

With this configuration, the protruding portion 21 is formed so that the first extending portion 21a and the second extending portion 21b cross each other. Specifically, an X-shaped protrusion 21 is formed. Thereby, the rigidity of the frame 20 can be further improved. Therefore, even if the light source module 10 expands, it is possible to further suppress the deformation of the frame 20.

Further, in the present embodiment, each of both ends of the first extending portion 21a in the longitudinal direction and each of both ends of the second extending portion 21b in the longitudinal direction are located at the ends of the main plate 20a.

With this configuration, the rigidity of the frame 20 can be further improved, so that the deformation of the frame 20 can be further suppressed.

Further, in the present embodiment, the first extending portion 21a and the second extending portion 21b are formed at positions different from those on the diagonal line of the main plate 20a, which is substantially rectangular. That is, the longitudinal end portions of the first extending portion 21a and the second extending portion 21b are formed at positions deviated from the corner portions of the rectangular main plate 20a. Specifically, one end of the first extending portion 21a in the longitudinal direction is located at the end of the first long side of the main plate 20a at a position recessed from the edge of the first short side of the main plate 20a. The other end of the first extending portion 21a in the longitudinal direction is located at the end of the second long side of the main plate 20a at a position recessed from the end edge of the second short side of the main plate 20a, and the second extending portion is located. One end of the 21b in the longitudinal direction is located at the end of the first long side of the main plate 20a at a position recessed from the edge of the second short side of the main plate 20a, and is located in the longitudinal direction of the second extending portion 21b. The other end is located at the end of the second long side of the main plate 20a, recessed from the edge of the first short side of the main plate 20a.

With this configuration, the rigidity of the frame 20 can be improved as compared with the case where the first extending portion 21a and the second extending portion 21b are formed on the diagonal line of the main plate 20a. Therefore, it is possible to effectively suppress the deformation of the frame 20.

Further, in the present embodiment, the protruding portion 21 has a third extending portion 21c extending over the entire circumference of the end portion of the main plate 20a.

With this configuration, the rigidity of the frame 20 can be greatly improved as compared with the case where the third extending portion 21c is not provided. Therefore, it is possible to effectively suppress the deformation of the frame 20.

Further, in the present embodiment, the protruding portion 21 protrudes toward the side opposite to the liquid crystal cell side. Specifically, the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c project toward the side opposite to the liquid crystal cell side.

With this configuration, the optical member 30 can be supported by the main plate 20a without bringing the optical member 30 into contact with the portion of the main plate 20a on which the protruding portion 21 is formed. That is, the optical member 30 can be supported by a flat portion having a large area of the main plate 20a in which the protruding portion 21 is not formed. As a result, even if the protruding portion 21 is formed on the main plate 20a as a reinforcing rib, the optical member 30 can be stably held by the frame 20.

Further, in the present embodiment, the protruding portion 21 is provided with a recessed portion 22 in which a part of the electric wire 90 is arranged.

With this configuration, even when the electric wire 90 crosses the protruding portion 21, by arranging the electric wire 90 in the recessed portion 22, the backlight 3 becomes thicker due to the thickness of the electric wire 90 in the portion overlapping the protruding portion 21. It can be suppressed. Further, since the electric wire 90 can be arranged in the recessed portion 22, it is possible to prevent the electric wire 90 from being sandwiched between the protruding portion 21 and another member and being disconnected at the portion where the protruding portion 21 and the electric wire 90 overlap. it can.

Further, in the present embodiment, the protruding portion 21 is provided with a through hole 23 through which the electric wire 90 is inserted.

With this configuration, the electric wire 90 can be routed to both sides of the main plate 20a through the through hole 23, so that the degree of freedom in the route (wiring) of the electric wire 90 is increased.

Specifically, the through hole 23 is provided in the vicinity of the light source module 10.

With this configuration, most of the electric wires 90 can be routed on the back side of the main plate 20a, and the electric wires 90 can be inserted into the through holes 23 in the vicinity of the light source module 10 to connect the electric wires 90 and the light source module 10.

(Modification example 1)
Next, the liquid crystal display device according to the first modification will be described with reference to FIG. FIG. 8 is an enlarged cross-sectional view showing a part of the frame 20A of the backlight used in the liquid crystal display device according to the first modification.

As shown in FIG. 8, the backlight frame 20A used in the liquid crystal display device according to the present modification has a configuration in which the reinforcing member 100 is arranged on the protruding portion 21 of the frame 20 according to the above embodiment. Other than that, the configuration is the same as that of the frame 20 in the above embodiment.

Specifically, in the frame 20A in the present modification, a reinforcing member 100 having a strength equal to or higher than that of the frame 20A is arranged in a recess (a portion inside the protruding portion 21) formed by the protruding portion 21. That is, the reinforcing member 100, which is harder than the frame 20A, is arranged on the protrusion 21.

With this configuration, the rigidity of the frame 20A can be greatly improved as compared with the frame 20 of the above-described embodiment in which the reinforcing member 100 is not arranged in the recess of the protruding portion 21. Therefore, it is possible to effectively suppress the deformation of the frame 20A.

As an example, the reinforcing member 100 is a plate-shaped reinforcing plate. For example, when the frame 20A is made of an aluminum plate, as the reinforcing member 100, for example, a reinforcing plate made of a steel material can be used. The reinforcing member 100 can be fixed to the frame 20A by an adhesive member such as double-sided tape or by welding or the like.

FIG. 8 illustrates the case where the reinforcing member 100 is arranged in the recess of the second extending portion 21b of the protruding portion 21, but the reinforcing member 100 is the first extending portion 21a of the protruding portion 21. It may be arranged in the recess. Further, the reinforcing member 100 may be arranged in the recess of the third extending portion 21c of the protruding portion 21. The reinforcing member 100 may be arranged in any one of the recesses of the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c, but the first extending portion 21a, It may be arranged in all the recesses of the second extending portion 21b and the third extending portion 21c. Further, the reinforcing member 100 may be partially arranged in the recess of the protruding portion 21, or a plurality of reinforcing members 100 may be arranged.

Further, the thickness of the reinforcing member 100 is preferably equal to or less than the depth of the recess of the protruding portion 21. As a result, even if the reinforcing member 100 is provided, it is possible to prevent the frame 20A from becoming thick, so that the overall thickness of the frame 20A can be maintained.

As described above, according to the liquid crystal display device and the backlight according to the present modification, since the frame 20A having a rigidity higher than that of the frame 20 in the above embodiment is used, the frame 20 is deformed by the expansion of the light source module 10. Can be further suppressed.

(Modification 2)
Next, the liquid crystal display device according to the second modification will be described with reference to FIGS. 9 and 10. FIG. 9 is a perspective view of the frame 20B of the backlight used in the liquid crystal display device according to the second modification when viewed from the rear side. FIG. 10 is a partially enlarged view showing a part of the frame 20B in an enlarged manner.

As shown in FIGS. 9 and 10, in the backlight frame 20B used in the liquid crystal display device according to the present modification, the electric wire 90 is arranged in the recess formed by the protrusion 21. Specifically, the frame 20B in the present modification has a configuration in which the protruding portion 21 of the frame 20 according to the above embodiment further has a fourth extending portion 21d, and other than that, in the above embodiment. It has the same configuration as the frame 20.

The fourth extending portion 21d is connected to at least one of the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c. In the present embodiment, one end of the fourth extending portion 21d is connected to the first extending portion 21a or the second extending portion 21b, and the other end of the fourth extending portion 21d is the second. 3 It is connected to the extending portion 21c.

The fourth extending portion 21d is formed in a convex shape. Specifically, the fourth extending portion 21d is opposite to the liquid crystal display panel 2 side (liquid crystal cell side) like the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c. It protrudes toward the side. The fourth extending portion 21d is formed so as to have a bent portion in a plan view, but may be linear so as not to have a bent portion.

The fourth extending portion 21d can be formed by drawing at the same time as forming the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c. In this case, the protruding amount (drawing depth) of the fourth extending portion 21d is the same as the protruding amount (drawing depth) of the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c. is there. Therefore, the outer surface and the inner surface of the protruding portion of the fourth extending portion 21d and the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c are flush with each other. Further, the width of the fourth extending portion 21d is, for example, the same as, but not limited to, the width of the first extending portion 21a, the second extending portion 21b, and the third extending portion 21c.

The electric wire 90 is arranged in the recessed portion formed by the fourth extending portion 21d. That is, the fourth extending portion 21d functions as a storage portion for accommodating the electric wire 90.

With this configuration, the electric wire 90 can be passed under the fourth extending portion 21d, so that the protruding portion 21 can function not only as a reinforcing rib but also as a storage portion for the electric wire 90. As a result, the electric wire 90 can be routed along the main plate 20a of the frame 20 without increasing the thickness of the frame 20.

As described above, according to the liquid crystal display device and the backlight according to the present modification, since the frame 20B is provided with the projecting portion 21, the frame 20 is deformed by the expansion of the light source module 10 as in the above embodiment. Can be suppressed. Moreover, since the fourth extending portion 21d is provided as a part of the protruding portion 21, the electric wire 90 can be housed in the fourth extending portion 21d and routed. Therefore, the electric wire 90 can be housed in the frame 20 without changing the thickness of the frame 20 while maintaining the strength of the frame 20B.

Further, in this modification, as shown in FIG. 9, the electric wire 90 is inserted through the connecting portion between the first extending portion 21a or the second extending portion 21b and the fourth extending portion 21d in the protruding portion 21. A hole 25 is provided.

With this configuration, the electric wire 90 routed to the front side of the frame 20 can be inserted into the through hole 25 and pulled out to the back side of the frame 20. By providing the through hole 25 in this way, the electric wire 90 can be routed to both sides of the main plate 20a through the through hole 25. Therefore, the degree of freedom in how to route the electric wire 90 (wiring) is increased.

(Other variants)
The backlight and the liquid crystal display device according to the present disclosure have been described above based on the embodiments, but the present disclosure is not limited to the above embodiments.

For example, in the above-described embodiment and the first and second modifications, the protruding portion 21 is formed into a drawn shape by drawing, but is not limited to this. For example, a metal member having the same aperture shape as the protrusion 21 may be attached to the main plate 20a. In this case as well, even if stress is applied to the frame 20 due to the expansion of the light source module 10, it is possible to suppress the deformation of the frame 20.

Further, in the above-described embodiment and the first and second modifications, the number of the liquid crystal display panel 2 is one, but the present invention is not limited to this. That is, a plurality of liquid crystal display panels may be used. Specifically, the configuration may be such that two crystal display panels are overlapped. In this case, the color image is displayed on the first liquid crystal display panel arranged at a position close to the observer, and displayed on the first liquid crystal display panel on the second liquid crystal display panel arranged behind the first liquid crystal display panel. It is preferable to display the monochrome image of the image corresponding to the color image to be displayed in synchronization with the color image. As a result, black can be tightened, so that a liquid crystal display device that displays a high-contrast image can be realized.

Further, in the above-described embodiments and modifications 1 and 2, the case where the backlight 3 is used for the liquid crystal display device 1 has been illustrated, but the present invention is not limited to this. The backlight 3 may be used as a light source for products other than liquid crystal display devices such as lighting fixtures.

In addition, a form obtained by applying various modifications to the above embodiment that can be conceived by a person skilled in the art, or a form realized by arbitrarily combining the components and functions in the embodiment without departing from the gist of the present disclosure. Is also included in this disclosure.

1 Liquid crystal display device 2 Liquid crystal display panel 3 Backlight 10 Light source module 11 Board 12 Light emitting elements 20, 20A, 20B Frame 20a Main plate 20b Side plate 20b1 First side plate 20b2 Second side plate 20b3 Third side plate 20b4 Fourth side plate 21 Protruding part 21a 1 Extended part 21b 2nd extended part 21c 3rd extended part 21d 4th extended part 22 Indented part 23, 25 Through hole 30 Optical member 31 Light guide plate 32 Reflector 33 Diffuse plate 40 Adhesive member 50 Front frame 60 Middle Frame 70 Circuit board 71 Flexible wiring board 80 Circuit cover 90 Wire 100 Reinforcing member

Claims (20)

A backlight that irradiates a liquid crystal cell with light.
With a long light source module
A support member for supporting the light source module is provided.
The support member has a main plate arranged so as to face the liquid crystal cell.
The main plate has a protrusion and
The protrusion has a portion extending at least in a direction intersecting the longitudinal direction of the light source module.
Backlight. Further, a light guide plate having an incoming light surface, an outgoing light surface, and a back surface facing the light emitting surface is provided.
The backlight according to claim 1, wherein the light source module is arranged so as to face the light entry surface of the light guide plate. The protrusions extend in a first direction extending in a first direction intersecting the longitudinal direction of the light source module and in a second direction intersecting the longitudinal direction of the light source module, and said. It has a second extension that intersects the first extension,
The backlight according to claim 1 or 2. The backlight according to claim 3, wherein each of both ends of the first extending portion in the longitudinal direction and each of both ends of the second extending portion in the longitudinal direction are located at the ends of the main plate. The plan view shape of the main plate is substantially rectangular.
One end in the longitudinal direction of the first extending portion is located at the end of the first long side of the main plate and recessed from the edge of the first short side of the main plate.
The other end of the first extending portion in the longitudinal direction is located at the end of the second long side of the main plate at a position recessed from the edge of the second short side of the main plate.
One end in the longitudinal direction of the second extending portion is located at the end of the first long side of the main plate and recessed from the edge of the second short side of the main plate.
The other end in the longitudinal direction of the second extending portion is located at the end of the second long side of the main plate, recessed from the edge of the first short side of the main plate.
The backlight according to claim 4. The protruding portion has a third extending portion extending over the entire circumference of the end portion of the main plate.
The backlight according to any one of claims 3 to 5. The first extending portion, the second extending portion, and the third extending portion project toward the side opposite to the liquid crystal cell side.
The backlight according to claim 6. Equipped with an electric wire connected to the light source module
The protruding portion is provided with a recessed portion in which a part of the electric wire is arranged.
The backlight according to any one of claims 1 to 7. The protruding portion is provided with a through hole through which the electric wire is inserted.
The backlight according to claim 8. The through hole is provided in the vicinity of the light source module.
The backlight according to claim 9. An electric wire connected to the light source module is arranged in a recess formed by the protrusion.
The backlight according to any one of claims 1 to 7. The protruding portion has a fourth extending portion connected to at least one of the first extending portion, the second extending portion, and the third extending portion.
An electric wire connected to the light source module is arranged in a recess formed by the fourth extending portion.
The backlight according to claim 11. One end of the fourth extending portion is connected to the first extending portion or the second extending portion.
The other end of the fourth extension is connected to the third extension.
The backlight according to claim 12. A through hole through which the electric wire is inserted is provided in the first extending portion or the connecting portion between the second extending portion and the fourth extending portion in the protruding portion.
The backlight according to claim 13. The support member has a side plate that stands on one side of the main plate and extends along the one side.
The light source module is attached to the inner surface of the side plate.
The backlight according to any one of claims 1 to 14. The light source module includes a long substrate and a plurality of light emitting elements mounted on the substrate along the longitudinal direction of the substrate.
The backlight according to any one of claims 1 to 15. A reinforcing member having a strength equal to or higher than that of the support member is arranged in the recess formed by the protrusion.
The backlight according to any one of claims 1 to 16. The thickness of the reinforcing member is equal to or less than the depth of the recess.
The backlight according to claim 17. The backlight according to any one of claims 1 to 18,
A liquid crystal cell arranged on the light emitting side of the backlight is provided.
Liquid crystal display device. The liquid crystal cell is a horizontal electric field type liquid crystal cell.
The liquid crystal display device according to claim 19.

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