WO2013031674A1

WO2013031674A1 - Illumination device, display device, and television reception device

Info

Publication number: WO2013031674A1
Application number: PCT/JP2012/071407
Authority: WO
Inventors: 真之助野澤
Original assignee: シャープ株式会社
Priority date: 2011-08-31
Filing date: 2012-08-24
Publication date: 2013-03-07

Abstract

This illumination device comprises: one or a plurality of light sources (17); a light source substrate (18) on which the light sources (17) are mounted; a chassis (14) which is a plate-shaped member, the light source substrate (18) being disposed on the panel surface thereof; and a reflecting layer (32) disposed on the light source substrate (18), the reflecting layer (32) being formed such that portions (32B) located closer to the center than portions located at the edges of the chassis have a higher yellowness index relative to portions (32A) located at the edges when the reflecting layer is viewed over the entire panel surface of the chassis (14).

Description

Lighting device, display device, and television receiver

The present invention relates to a lighting device, a display device, and a television receiver.

In recent years, image display devices such as television receivers are shifting from conventional cathode ray tubes to thin display devices to which thin display elements such as liquid crystal panels and plasma display panels are applied. When a liquid crystal panel is used as the display element, the liquid crystal panel does not emit light, and thus a backlight device is separately required as a lighting device.

Patent Document 1 discloses a backlight device that includes an LED mounted on a surface of a mounting substrate as a light source, and the surface of the mounting substrate is covered with a light reflecting member. The light reflecting member is made of a material (so-called white solder resist) obtained by further adding a high light reflecting material having high light reflectivity to a solder resist, and the material is printed and applied on the mounting surface of the mounting substrate. Is obtained. According to such a backlight device, it is possible to suppress the absorption of light on the surface of the mounting substrate, and to improve the luminance and reduce the occurrence of luminance unevenness.

JP 2011-90977 A

(Problems to be solved by the invention)
By the way, when the light emitting portion of the backlight device is viewed from the front side, there is a portion that is darkly shown at the end of the light emitting portion due to insufficient light quantity, which is a problem. This is because the number of light sources that supply light is smaller at the end of the backlight device than at the center.

In order to make the luminance of the light emitting unit uniform, for example, the current value for driving the LED is changed, and the luminance of the LED arranged on the end side of the backlight device is changed to the luminance of the LED arranged on the central side. It is possible to make it relatively higher. However, since this method requires special electrical control, a simpler method is required.

The present invention has been completed based on the above circumstances, and an object thereof is to provide a technique for suppressing luminance unevenness of a lighting device with a simple configuration.

(Means for solving the problem)
An illumination device according to the present invention includes one or more light sources, a light source substrate on which the light sources are mounted, a plate-shaped member, and a chassis in which the light source substrate is disposed on the plate surface, A reflective layer disposed on the light source substrate, and when viewed from the entire plate surface of the chassis, a portion located on the end side of the chassis is more central than a portion located on the end side. And a reflective layer having a relatively high degree of yellowing in a portion located on the side.

In the illumination device, the reflective layer may be composed of a solder resist layer that increases in yellowing degree when irradiated with ultraviolet rays.

The illumination device includes a lens member that diffuses light, the lens member being disposed on the plate surface of the light source substrate and covering a light emission side of the light source, and the reflective layer includes at least the lens member It can be formed in the overlapping part.

In the illumination device, the reflection sheet reflects light, and has an opening that is larger than the outer shape of the lens member. The lens member is inserted through the opening, and the plate surface of the light source substrate. A reflection sheet is provided on the top, and the reflection layer may be formed at least in a portion exposed from the opening.

In the illuminating device, when the reflective layer is entirely replaced with a white solder resist layer that is not yellowed, the degree of yellowing in the reflective layer based on the luminance distribution of planar light emitted from the light source The distribution of can be defined.

In the lighting device, a difference between a light reflectance of a portion located on the end side of the reflective layer and a light reflectance of a portion located on the center side of the reflective layer is 5% or more It can be. For example, when the yellowing degree of the portion located on the central portion side in the reflective layer is set relatively higher than the yellowing degree of the portion located on the end side in the reflective layer. The light reflectance of the portion located on the end side in the reflective layer can be set to be 5% or more higher than the light reflectance of the portion located on the center side in the reflective layer.

In the illuminating device, the chassis further includes a light emitting unit that emits light from the light source, and further includes an optical member arranged to cover the light emitting unit, and the optical member includes the light source. A diffusion plate having a function of diffusing light from, an optical sheet having at least one of a function of condensing the light transmitted through the diffusion plate, and a function of diffusing the light transmitted through the diffusion plate; Can be provided.

In the illumination device, the light source may include a light emitting diode.

The display device according to the present invention includes the illumination device and a display panel that performs display using light from the illumination device.

In the display device, the display panel may be a liquid crystal panel in which liquid crystal is sealed between a pair of substrates.

A television receiver according to the present invention includes the display device.

(The invention's effect)
According to the present invention, it is possible to suppress luminance unevenness of the lighting device with a simple configuration.

1 is an exploded perspective view showing a schematic configuration of a television receiver according to Embodiment 1 of the present invention. Exploded perspective view showing schematic configuration of liquid crystal display device Sectional drawing of the liquid crystal display device along the A-A 'line | wire shown by FIG. Plan view of lighting device with optical member and frame removed An enlarged plan view showing the solder resist layer exposed from the lens insertion hole of the reflection sheet C-C 'line sectional view of FIG. Top view of the LED board placed on the bottom plate of the chassis Graph showing total reflectance of solder resist layer after yellowing B-B 'line sectional view of FIG. The top view of the LED board distribute | arranged on the baseplate of the chassis with which the illuminating device of Embodiment 2 is provided. The top view of the LED board distribute | arranged on the baseplate of the chassis with which the illuminating device of Embodiment 3 is provided. FIG. 6 is an exploded perspective view showing a schematic configuration of a liquid crystal display device according to Embodiment 4. Sectional view showing the liquid crystal display device cut in the short side direction Plan view of LED board

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. In this embodiment, the liquid crystal display device 10 is illustrated. In addition, X-axis, Y-axis, and Z-axis are shown in a part of each drawing, and each axial direction is drawn so that it may become a common direction in each drawing. Also, the upper side of FIGS. 2 and 3 is the front side, and the lower side is the back side.

As shown in FIG. 1, the television receiver TV according to the present embodiment includes a liquid crystal display device 10, front and back cabinets Ca and Cb that are accommodated so as to sandwich the liquid crystal display device 10, a power source P, and a tuner T. And a stand S. The liquid crystal display device (display device) 10 has a horizontally long rectangular shape (rectangular shape) as a whole and is accommodated in a vertically placed state. As shown in FIG. 2, the liquid crystal display device 10 includes a liquid crystal panel 11 that is a display panel and a backlight device (illumination device) 12 that is an external light source, and these are integrated by a frame-like bezel 13 or the like. It is designed to be retained.

Next, the liquid crystal panel 11 and the backlight device 12 constituting the liquid crystal display device 10 will be described. Among these, the liquid crystal panel (display panel) 11 has a rectangular shape when viewed in a plane, and a pair of glass substrates are bonded together with a predetermined gap therebetween, and a liquid crystal is formed between the glass substrates. It is set as the enclosed structure. One glass substrate is provided with a switching element (for example, TFT) connected to a source wiring and a gate wiring orthogonal to each other, a pixel electrode connected to the switching element, an alignment film, and the like. The substrate is provided with a color filter and counter electrodes in which colored portions such as R (red), G (green), and B (blue) are arranged in a predetermined arrangement, and an alignment film. A polarizing plate is disposed on the outside of both substrates.

Subsequently, the backlight device 12 will be described. As shown in FIG. 2, the backlight device 12 is a substantially box-shaped chassis having an opening 14b (light emitting portion) for emitting light from a light source on the light emitting portion 12a side (liquid crystal panel 11 side). 14, an optical member 15 disposed so as to cover the opening 14 b of the chassis 14 (a diffusion plate 15 a and a plurality of optical sheets 15 b disposed between the diffusion plate 15 a and the liquid crystal panel 11), and the chassis 14. The frame 16 is disposed along the outer edge of the optical member 15 and holds the outer edge of the optical member 15 between the frame 14 and the chassis 14. Further, in the chassis 14, as shown in FIG. 3 and the like, an LED 17 (Light Emitting Diode) as a light source, an LED board 18 (light source board) on which the LED 17 is mounted, and an LED 17 on the LED board 18. And a diffusing lens 19 (lens member) attached at a position corresponding to. The chassis 14 is provided with a reflection sheet 21 that reflects the light in the chassis 14 toward the optical member 15. In the backlight device 12, the optical member 15 side is closer to the light emitting portion 12 a side than the LED 17. Below, each component of the backlight apparatus 12 is demonstrated.

The chassis 14 is made of metal, and as shown in FIG. 3 and the like, a bottom plate 14a having a rectangular shape like the liquid crystal panel 11, a side plate 14c rising from an outer end of each side of the bottom plate 14a, and a side plate 14c. It consists of a receiving plate 14d projecting outward from the rising edge, and as a whole, has a shallow substantially box shape (substantially shallow dish shape) opened toward the front side. The long side direction of the chassis 14 matches the X-axis direction, and the short side direction matches the Y-axis direction. A frame 16 and an optical member 15 to be described below can be placed on each receiving plate 14d in the chassis 14 from the front side. The frame 16 is screwed to the receiving plate 14d.

As shown in FIG. 2, the optical member 15 has a horizontally long rectangular shape (rectangular shape) in a plan view, like the liquid crystal panel 11 and the chassis 14. As shown in FIG. 3, the optical member 15 is placed between the liquid crystal panel 11 and the LED 17 while covering the opening 14 b of the chassis 14 by placing the outer edge portion on the receiving plate 14 d. The The optical member 15 includes a diffusion plate 15a disposed on the back side (the side opposite to the LED 17 side and the light emitting unit 12a side), and an optical sheet 15b disposed on the front side (the liquid crystal panel 11 side and the light emitting unit 12a side). Consists of The diffusion plate 15a has a structure in which a large number of diffusion particles are dispersed in a substantially transparent resin base material having a predetermined thickness, and has a function of diffusing transmitted light. The optical sheet 15b has a sheet shape that is thinner than the diffusion plate 15a, and two optical sheets 15b are laminated. Specific types of the optical sheet 15b include, for example, a diffusion sheet, a lens sheet, a reflective polarizing sheet, and the like, which can be appropriately selected and used.

As shown in FIG. 2, the frame 16 has a frame shape along the outer peripheral edge of the liquid crystal panel 11 and the optical member 15. An outer edge portion of the optical member 15 can be sandwiched between the frame 16 and each receiving plate 14d (see FIG. 3). The frame 16 can receive the outer edge portion of the liquid crystal panel 11 from the back side, and can sandwich the outer edge portion of the liquid crystal panel 11 with the bezel 13 disposed on the front side (see FIG. 3).

Next, the LED 17 and the LED board 18 on which the LED 17 is mounted will be described. As shown in FIG. 6, the LED 17 has a configuration in which an LED chip is sealed with a resin material on a substrate portion fixed to the LED substrate 18. The LED chip mounted on the substrate unit has one main emission wavelength, and specifically, one that emits blue light in a single color is used. On the other hand, a phosphor that converts blue light emitted from the LED chip into white light is dispersed and blended in the resin material for sealing the LED chip. As a result, the LED 17 can emit white light. The LED 17 is a so-called top type in which a surface opposite to the mounting surface with respect to the LED substrate 18 is a light emitting surface 17a. The optical axis LA of the LED 17 is set to substantially coincide with the Z-axis direction (direction orthogonal to the main plate surfaces of the liquid crystal panel 11 and the optical member 15). Note that the light emitted from the LED 17 spreads radially to some extent within a predetermined angle range around the optical axis LA, but its directivity is higher than that of a cold cathode tube or the like. That is, the emission intensity of the LED 17 shows an angular distribution that tends to decrease as the direction along the optical axis LA is high and the tilt angle with respect to the optical axis LA increases.

As shown in FIG. 7, the LED substrate 18 includes a base material 30 that has a rectangular shape (rectangular shape) in a plan view, and the long side direction is the Y-axis direction (the short side of the bottom plate 14 a of the chassis 14). And extending along the bottom plate 14a in the chassis 14 in a state where the short side direction matches the X-axis direction (long side direction of the bottom plate of the chassis 14a).

The substrate 30 of the LED substrate 18 is made of a metal such as the same aluminum material as the chassis 14, and a pattern wiring (not shown) made of a metal film such as a copper foil is formed on the surface of the substrate 30 via an insulating layer (not shown). The configuration is The pattern wiring is arranged on the side of the plate surface 18b (the plate surface on which the light source is mounted) on which the LED 17 is mounted, and is electrically connected to the LED 17. Further, a white solder resist layer 32 (reflection layer) for protecting the wiring is laminated on the surface of the pattern wiring. The solder resist layer 32 will be described in detail later. And among the plate surfaces of the base material 30 of the LED substrate 18, the LED 17 having the above-described configuration is surface-mounted as shown in FIG. 6 on the surface facing the front side (the surface facing the optical member 15 side). Has been.

As shown in FIG. 7, a plurality of LEDs 17 are arranged on the LED substrate 18 in a straight line at equal intervals along the long side direction (Y-axis direction) of the LED substrate 18. In the case of the present embodiment, on the LED substrate 18, three rows of a plurality (9) of LEDs 17 are formed in parallel with each other. The LEDs 17 are connected in series with each other by pattern wiring. The pitch between the LEDs 17 on the LED substrate 18 is substantially constant. A connector 18a is provided at one end of the LED substrate 18 on the long side.

In the case of the present embodiment, six LED substrates 18 having the same size are accommodated in the chassis 14 in a line along the X-axis direction (long side direction of the bottom plate of the chassis 14a). On the bottom plate 14a of the chassis 14, the LEDs 17 mounted on the LED substrates 18 are arranged in a matrix (matrix). The interval (pitch) between the LEDs 17 arranged in a matrix is set to be substantially constant. 4 and 7, each connector 18a provided on each LED board 18 is aligned with one long side of the chassis 14, and an external control circuit (not shown). Are electrically connected to each other. Then, lighting and extinguishing of each LED 17 on each LED board 18 are collectively controlled by the control circuit. The LED substrate 18 is fixed to the bottom plate 14a of the chassis 14 using a rivet-shaped fixing member (not shown).

The diffusing lens 19 is made of a synthetic resin material (for example, polycarbonate, acrylic, etc.) that is substantially transparent (having high translucency) and has a higher refractive index than air. As shown in FIG. 5, the diffusing lens 19 is formed in a substantially circular shape when seen in a plan view, and covers each LED 17 individually from the front side with respect to the LED substrate 18, that is, when viewed from the plan view with each LED 17. Each is attached to overlap. The diffusing lens 19 can emit light having a high directivity (high) emitted from the LED 17 while diffusing. By covering the LED 7 with the diffusion lens 19, the number of LEDs 17 installed in the chassis 14 can be reduced. The diffusing lens 19 is disposed at a position that is substantially concentric with the LED 17 in a plan view. The diffuser lens 19 is sufficiently larger in both the X-axis direction and the Y-axis direction than the LED 17. On the other hand, the diffusing lens 19 has dimensions smaller than the LED substrate 18 in the X-axis direction and the Y-axis direction. Therefore, the LED substrate 18 is disposed in a region overlapping with the diffusing lens 19 in the Z-axis direction.

Of the diffusing lens 19, a surface facing the LED substrate 18 is a light incident surface 19a on which light from the LED 17 is incident, whereas a surface facing the optical member 15 is a light emitting surface 19b that emits light. It is said. Among these, as shown in FIG. 6, the light incident surface 19a is generally parallel to the plate surface 18b of the LED substrate 18 as shown in FIG. The side recess 19c is formed to have an inclined surface. The light incident side concave portion 19c has a substantially conical shape and is disposed at a substantially concentric position in the diffusing lens 19 and opens toward the back side, that is, the LED 17 side. The light incident side concave portion 19c has a substantially inverted V-shaped cross section, and its peripheral surface is an inclined surface inclined with respect to the Z-axis direction. Therefore, the light emitted from the LED 17 and entering the light incident side concave portion 19c enters the diffusion lens 19 through the inclined surface, but at that time, the amount of the inclination angle of the inclined surface with respect to the optical axis LA is as follows. The light is refracted in a direction away from the center, that is, a wide angle, and enters the diffusing lens 19.

The diffusing lens 19 is provided with mounting legs 19 d that project toward the LED substrate 18 and that serve as a structure for attaching the diffusing lens 19 to the LED substrate 18. Three attachment legs 19d are arranged in the diffuser lens 19 at positions closer to the outer peripheral end than the light incident side recess 19c, and the lines connecting the attachments form a substantially equilateral triangle when viewed in a plane. Arranged in position. Each mounting leg 19d has its tip fixed to the LED substrate 18 with an adhesive or the like. The diffusing lens 19 is fixed to the LED substrate 18 via the mounting leg portion 19d, so that a predetermined gap is formed between the light incident surface 19a and the LED substrate 18. In this gap, incidence of light from a space outside the diffusion lens 19 in a plan view is allowed.

The light exit surface 19b of the diffusion lens 19 is formed in a flat and substantially spherical shape. As a result, the light emitted from the diffusing lens 19 can be emitted while being refracted in a direction away from the center at the interface with the external air layer, that is, a wide angle. A light emitting side recess 19e is formed in a region of the light emitting surface 19b that overlaps the LED 17 when seen in a plan view. The light emitting side concave portion 19e has a substantially bowl shape, and is formed in a flat and substantially spherical shape with a peripheral surface having a downward slope toward the center. Further, the angle formed by the tangent of the peripheral surface of the light exit side recess 19e with respect to the optical axis LA of the LED 17 is relatively larger than the angle formed by the inclined surface of the light incident side recess 19c with respect to the optical axis LA. It is said. By forming a light emitting side recess 19e in a region of the light emitting surface 19b that overlaps the LED 17 when viewed in plan, most of the light from the LED 17 is emitted while being refracted at a wide angle, or part of the light from the LED 17 Can be reflected to the LED substrate 18 side.

The reflection sheet 21 is made of a synthetic resin, and the surface of the reflection sheet 21 is white with excellent light reflectivity. As shown in FIG. 4, the reflection sheet 21 has a size that is laid over almost the entire inner surface of the chassis 14, so that all the LED boards 18 arranged in parallel in the chassis 14 are arranged from the front side. It is possible to cover all at once. The reflection sheet 21 can efficiently raise the light in the chassis 14 toward the optical member 15 side. The reflection sheet 21 extends along the bottom plate 14a of the chassis 14 and covers a large portion of the bottom plate 14a. The reflection sheet 21 rises from each outer end of the bottom portion 21a to the front side and is inclined with respect to the bottom portion 21a. The four rising portions 21b and the extending portions 21c that extend outward from the outer ends of the respective rising portions 21b and are placed on the receiving plate 14d of the chassis 14 are configured. The bottom 21a of the reflection sheet 21 is disposed so as to overlap the front side with respect to the plate surface 18b on which the LEDs 17 of each LED board 18 are mounted. In addition, a lens insertion hole 21d (opening) through which each diffusion lens 19 is inserted is provided in the bottom portion 21a of the reflection sheet 21 at a position overlapping with each diffusion lens 19 (each LED 17) in plan view.

The lens insertion holes 21 d are individually inserted through the respective diffusion lenses 19, and are arranged in a matrix on the bottom 21 a of the reflection sheet 21 in the same manner as the LEDs 17. As shown in FIG. 5, the lens insertion hole 21 d has a circular shape when seen in a plan view, and has a diameter larger than that of the diffusing lens 19. Thereby, when the reflection sheet 21 is laid in the chassis 14, each diffusing lens 19 can be surely passed through each lens insertion hole 21 d regardless of the presence or absence of a dimensional error. Further, the diameter dimension of the lens insertion hole 21 d is set to be smaller than the short side dimension of the LED substrate 18. Thus, the solder resist layer 32 provided on the LED substrate 18 is exposed in the lens insertion hole 21d, and the chassis 14 is not exposed. The reflection sheet 21 is fixed to the LED board 18 using the above-described rivet-like fixing member (not shown) for fixing the LED board 18 to the bottom plate 14a.

2 and 3, the support member 20 has a shape protruding from the bottom plate 14a of the chassis 14 toward the front side. The base side of the support member 20 has a rivet shape and has a function of fixing the LED substrate 18 to the bottom plate 14a. Moreover, the front end side of the support member 20 is rod-shaped, and has a function of supporting the optical member 15 from the back side. With this support member 20, the positional relationship in the Z-axis direction between the LED 17 and the optical member 15 can be maintained constant, and deformation (deflection) of the optical member 15 can be restricted.

Next, the solder resist layer 32 will be described in detail. The solder resist layer 32 of the present embodiment is formed on the front surface (mounting surface) of the LED substrate 18, and a white solder resist (hereinafter, white solder resist) is appropriately used as necessary. Consists of yellowing. The white solder resist is made, for example, by dispersing a predetermined amount of a white pigment such as titanium oxide (rutile titanium oxide, etc.) or barium titanate in an ultraviolet curable base resin. This type of white solder resist has a property of being excellent in light reflectivity as compared with a general-purpose green solder resist. Further, when the white solder resist is continuously irradiated with ultraviolet rays, the color of the white solder resist is changed from white to yellow (yellowing) and the light reflectance is lowered. The solder resist layer 32 of the present embodiment is formed using such a property of the white solder resist.

The solder resist layer 32 is formed so as to sandwich a pattern wiring (not shown) with an insulating layer (not shown) formed on the base material 30 of the LED substrate 18. The solder resist layer 32 is provided on substantially the entire surface of the front surface of the LED substrate 18 except for the portion where the LEDs 17 are mounted. When the solder resist layer 32 is formed on the LED substrate 18, first, an uncured white solder resist having fluidity is printed and applied on the LED substrate 18 with a predetermined thickness. Next, an exposure process and a development process are performed on the coating film of the white solder resist applied on the LED substrate 18. Thereafter, the coating film of the white solder resist is irradiated with infrared rays to dry the coating film, and if necessary, the coating film is irradiated with ultraviolet rays to yellow the coating film.

In the case of the present embodiment, of the six LED substrates 18, two LED substrates 18 include a white (unyellowed) solder resist layer 32 (32A). The remaining four LED substrates 18 include a solder resist layer 32 (32B) that has been yellowed by the yellowing treatment. As shown in FIG. 7, a white (non-yellowing) solder resist layer 32 (32A) is formed on two LED substrates 18 at both ends of the six LED substrates 18 arranged in a line. ing. A yellowed solder resist layer 32 (32B) is formed on the four LED substrates 18 between them. The solder resist layer 32A is irradiated with ultraviolet rays within an allowable range that does not cause yellowing for the purpose of performing an exposure process, but is not irradiated for the purpose of performing the yellowing process. On the other hand, the solder resist layer 32B is irradiated with a predetermined amount of ultraviolet rays for the purpose of performing a yellowing process after the exposure process.

For convenience of explanation, the LED substrates 18 arranged on the bottom plate 14a in FIG. 7 and the like are arranged in order from the left end to the right end, the first LED substrate 18, the second LED substrate 18, the third LED substrate 18, and the fourth LED substrate. 18, the fifth LED board 18, and the sixth LED board 18.

FIG. 8 is a graph showing the total reflectance of the solder resist layer 32 (32B) after yellowing. The horizontal axis in FIG. 8 corresponds to the wavelength (nm) of light irradiated to the solder resist film 32, and the vertical axis corresponds to the total reflectance (%). Further, in FIG. 8, the graph indicated by the solid line corresponds to the yellowed solder resist layer 32 (32 B), and the graph indicated by the alternate long and short dash line is the white (unyellowed) solder resist layer. 32 (32A). As shown in FIG. 8, the total reflectance of the yellowed solder resist layer 32 (32B) is lower than the total reflectance of the white (unyellowed) solder resist layer 32 (32A). Yes. For example, the total reflectance in light having a wavelength of 540 nm is 86.3% in the case of the white (unyellowed) solder resist layer 32 (32A), whereas the yellowed solder resist layer 32 (32B). ) Is 80.5%. Each light reflectance is based on an average light reflectance within a measurement diameter measured by a measuring apparatus (CM-700d) manufactured by Konica Minolta.

Further, the chromaticity (yellowing degree) of the white (non-yellowing) solder resist layer 32 (32A) is the CIE (Commission Internationale d'Eclairage: International Illumination Commission) 1931 chromaticity coordinates display value ( When expressed in so-called CIEYxy system coordinates), (x, y) = (0.31, 0.33). Further, the chromaticity (yellowing degree) of the yellowed solder resist layer 32 (32B) is (x, y) = (0.32, 0.34). Therefore, it can be seen that the chromaticity (yellowing degree) of the solder resist layer 32 (32B) is set higher than the chromaticity (yellowing degree) of the solder resist layer 32 (32A). In this specification, the chromaticity (yellowing degree) of the solder resist layer (reflective layer) 32 is expressed by a coordinate value (x, y) of the CIEYxy system.

The chromaticity (yellowing degree) of the solder resist layer 32 is first determined by visually identifying the color name of each object color (JIS Z 8102: 2001) based on the color sample. Then, from the specified color name, the coordinate value of the CIEXY system (CIEXYZ system) is specified. Specifically, in the case of the solder resist layer 32A, the color name is specified as #fffffc. Then, from the specified color name, the CIEXYZ coordinate value is specified as (X, Y, Z) = (0.95, 1.00, 1.07). Further, when the CIEXYZ coordinate values are converted into the CIEXYxy coordinate values, the chromaticity (yellowing degree) of the solder resist layer 32A is specified as (x, y) = (0.31, 0.33). . It should be noted that a relational expression of x = X / (X + Y + Z) and y = Y (X + Y + Z) exists between the coordinate value (x, y) of the CIEXYxy system and the coordinate value (X, Y, Z) of the CIEXYZ system. It is made up.

On the other hand, in the case of the solder resist 32B, the color name is specified as # fffff5. Then, from the specified color name, the CIEXYZ coordinate value is specified as (X, Y, Z) = (0.94, 0.99, 1.01). Further, when the CIEXYZ coordinate value is converted into the CIEXYxy coordinate value, the chromaticity (yellowing degree) of the solder resist layer 32B is specified as (x, y) = (0.32, 0.34). .

In the case of this embodiment, the thickness of each solder resist layer 32 (32A, 32B) formed on each LED substrate 18 is set to be substantially constant. The thickness of the solder resist layer 32 is set in the range of 5 μm to 30 μm, for example.

As shown in FIG. 6, the solder resist layer 32 is formed in a portion overlapping the diffusing lens 19. The solder resist layer 32 faces the light incident surface 19a of the diffusion lens 19 in the Z-axis direction and is located between the diffusion lens 19 and the base material of the LED substrate 18. Therefore, the solder with respect to the light returned from the diffusion lens 19 side to the LED substrate 18 side or the light entering the space between the diffusion lens 19 and the LED substrate 18 from a space outside the diffusion lens 19 when seen in a plane. The resist layer 32 can again reflect the light toward the diffusion lens 19 side.

Further, as shown in FIG. 5, the solder resist layer 32 is formed on the entire portion overlapping with the lens insertion hole 21 d of the reflection sheet 21 except for a portion where the LED 17 is mounted when seen in a plan view. As a result, the solder resist layer 32 is exposed from the lens insertion hole 21d. In addition, it sets so that things other than the soldering resist layer 32 may hardly be exposed from the lens penetration hole 21d of the reflective sheet 21 of this embodiment.

As shown in FIG. 7, in the longitudinal direction (X-axis direction) of the bottom plate 14a, the solder resist layers 32A located on the LED substrates 18 (the first LED substrate 18 and the sixth LED substrate 18) at both ends are more than Each solder resist layer 32 B located on each LED board 18 (second LED board 18, third LED board 18, fourth LED board 18, and fifth LED board 18) on the center side side has a relatively higher degree of yellowing. ing. As shown in FIG. 4, when the reflection sheet 21 is attached to the chassis 14, it is located on each LED board 18 (first LED board 18 and sixth LED board 18) at both ends and exposed from the lens insertion hole 21 d. Each LED substrate 18 (the second LED substrate 18, the third LED substrate 18, the fourth LED substrate 18, and the fifth LED substrate 18) located on the center side of each solder resist layer 32A to be exposed and exposed from the lens insertion hole 21d. The solder resist layer 32B has a relatively high degree of yellowing.

FIG. 9 is a cross-sectional view taken along line B-B ′ of FIG. The LED 17 on the first LED board 18 is shown on the left side of FIG. 9, and the LED 17 on the second LED board 18 is shown on the right side of FIG. As described above, the white (non-yellowing) solder resist layer 32 (32A) is formed on the base material 30 of the first LED substrate 18, and the yellowing is performed on the base material of the second LED substrate 18. The solder resist layer 32 (32B) thus formed is formed. The portions of the solder resist

layers

32A and 32B formed around the LED 17 and the diffusing lens 19 are exposed from the lens insertion holes 21d of the reflection sheet 21, respectively.

Some of the light emitted from the LED 17 passes directly toward the front optical member 15 through the diffusing lens 19 and once travels toward the reflection sheet 21 in the periphery. . The light traveling toward the reflection sheet 21 or the like is reflected by the reflection sheet 21 or the like and proceeds toward the solder resist layer 32 (32A, 32B) exposed from the lens insertion hole 21d. There is something. In FIG. 9, light L1 traveling toward the solder resist layer 32A and light L3 traveling toward the solder resist layer 32B are schematically shown by arrows, respectively.

The light L1 is reflected with high efficiency by the solder resist layer 32A. The reflected light L2 of the light L1 enters the diffusing lens 19 from the light incident surface 19a of the diffusing lens 19 covering the solder resist layer 32A, and is emitted as diffused light from the light emitting surface 19e. On the other hand, the light L3 is reflected with relatively low efficiency by the solder resist layer 32B. The reflected light L4 of the light L3 enters the diffusing lens 19 from the light incident surface 19a of the diffusing lens 19 covering the solder resist layer 32B, and is emitted as diffused light from the light emitting surface 19e. Therefore, for example, when the light L1 and the light L3 have the same condition (light quantity), the reflected light L2 of the light L1 has a larger light quantity than the reflected light L4 of the light L3.

When the liquid crystal display device 10 is used, each 17 provided in the backlight device 12 is turned on and an image signal is supplied to the liquid crystal panel 11. Thereby, a predetermined image is displayed on the display surface of the liquid crystal panel 11. The light emitted from each LED 17 that is lit first enters the light incident surface 19 a of the diffusion lens 19. At this time, most of the light enters the inclined surface of the light incident recess 19c in the light incident surface 19a, and enters the diffusing lens 19 while being refracted at a wide angle according to the inclination angle. The light that has entered the diffusing lens 19 propagates through the diffusing lens 19 and then exits from the light exit surface 19b. The light emitting surface 19b is substantially spherical in shape, and light is emitted while being refracted at a wider angle at the interface with the external air layer. In addition, in the region where the amount of light from the LED 17 is the largest in the light exit surface 19b, the light exit side recess 19e having a substantially bowl shape is formed, and the peripheral surface has a flat and substantially spherical shape. Light can be emitted while being refracted at a wide angle on the peripheral surface of the light emitting side recess 19e, or reflected to the LED substrate 18 side.

The main part of the light emitted from the diffusion lens 19 is emitted to the light emitting part 12 a side (liquid crystal panel 11) side of the backlight device 12 through the optical member 15. Further, the remaining part of the light emitted from the diffusing lens 19 is directed to the reflective sheet 21 or the solder resist layer 32 side, and after being reflected by the reflective sheet 21 or the solder resist layer 32, the light emitting part 12a side. It goes to (liquid crystal panel 11).

By the way, the light emitting part 12 a included in the backlight device 12 includes a rectangular part surrounded by the inner edge part of the frame 16. When the bottom plate 14a side of the chassis 14 is viewed from the light emitting portion 12a, the LED 17 is not disposed in the portion corresponding to the periphery of the light emitting portion 12a, although the rising portion 21b of the reflecting sheet 21 is disposed. . On the other hand, a plurality of LEDs 17 are arranged in a matrix in a portion corresponding to the inner side (center side) of the peripheral edge of the light emitting portion 12a. Therefore, the backlight device 12 inevitably has a configuration in which the amount of light on the peripheral side of the light emitting portion 12a is smaller than the amount of light on the center side, considering only the arrangement relationship of the LEDs 17.

However, in the backlight device 12 of the present embodiment, in the planar light emitted from the light emitting portion 12a, the occurrence of uneven brightness between the peripheral portion and the central portion is suppressed. The principle will be described below.

As described above, the backlight device 12 of the present embodiment is more central in the longitudinal direction (X-axis direction) of the bottom plate 14a of the chassis 14 than the solder resist layers 32A located on the LED substrates 18 at both ends. Each solder resist layer 32 B located on each LED substrate 18 on the part side is set to have a relatively high degree of yellowing. These solder resist layers 32A are exposed from the lens insertion holes 21d of the reflection sheet 21, respectively. As shown in FIG. 9, the amount of light reflected by the solder resist layer 32A (reflected light L2) is larger than the amount of light reflected by the solder resist layer 32B (reflected light L4). Therefore, at least both end portions on the short side of the peripheral portion of the light emitting portion 12a are supplemented with a larger amount of light by the light reflected by the solder resist layer 32 than in the central portion. As a result, luminance unevenness between the peripheral portion of the light emitting portion 12a and the central portion is suppressed.

It should be noted that, among the peripheral portions of the light emitting portion 12a, both end portions on the short side are the places where the amount of light is most likely to be insufficient. This is because, among the peripheral portions of the light emitting portion 12a, both ends on the short side have a smaller number of LEDs 17 disposed than both ends on the long side of the light emitting portion 12a. . As in the present embodiment, when the luminance unevenness between the end portions on the short side of the light emitting portion 12a and the central portion of the light emitting portion 12a is at least suppressed, in the case of human vision, the light emission The planar light emitted from the portion 12a is recognized as being substantially uniform as a whole.

In this embodiment, the solder resist layer 32 provided on the LED substrate 18 is used as a reflective layer. The solder resist layer 32 is formed by subjecting a white solder resist to yellowing treatment by ultraviolet irradiation as necessary. Therefore, the backlight device 12 of the present embodiment can suppress luminance unevenness with a simple configuration. Furthermore, the backlight device 12 of the embodiment can also reduce the manufacturing cost.

In the present embodiment, the solder resist layer 32 is formed at least in a portion overlapping the diffusing lens 19. Therefore, the light reflected by the solder resist layer 32 enters the diffusing lens 19, and part of the light is diffused toward both end portions along the Y-axis direction of the light emitting portion 12 a of the backlight device 12. Further, the luminance at the end of the light emitting part 12a can be further improved.

In the present embodiment, the solder resist layer 32 is formed at least in a portion overlapping with the lens insertion hole 21d of the reflection sheet 21. Therefore, the light that has entered the lens insertion hole 21d can be reflected by the solder resist layer 32, and the luminance at the end of the light emitting portion 12a can be further improved.

Further, in the present embodiment, since the diffusion plate 15a and the optical sheet 15b are provided, the light emitted from the opening 14b of the chassis 14 is transmitted through the diffusion plate 15a and the optical sheet 15b, and further. The luminance of the light emitting part 12a of the backlight device 12 can be made uniform.

Further, in the present embodiment, the light source is the LED 17 and includes a light emitting diode, so that it is possible to increase the luminance.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIG. In the following embodiments, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted. In this embodiment, the backlight device 12A is illustrated. FIG. 10 is a plan view of the LED substrate 18 disposed on the bottom plate 14a of the chassis 14 included in the illumination device (backlight device) 12A according to the second embodiment. The backlight device 12A of this embodiment is different from that of Embodiment 1 in the solder resist layer 32 (32C) formed on the third LED substrate 18 and the fourth LED substrate 18, respectively.

As shown in FIG. 10, among the six LED substrates 18, the first LED substrate 18 disposed at the left end and the sixth LED substrate 18 disposed at the right end are the solder as in the first embodiment. A resist layer 32 (32A) is provided. Moreover, the 2nd LED board 18 and the 5th LED board 18 are provided with the soldering resist layer 32 (32B) similarly to Embodiment 1. FIG. However, unlike the first embodiment, the third LED substrate 18 and the fourth LED substrate 18 include a solder resist layer 32C having a higher degree of yellowing than the solder resist layer 32B.

The solder resist layer 32C is made of a material further yellowed than the solder resist layer 32B by ultraviolet irradiation. The solder resist layer 32C is set to have a longer ultraviolet irradiation time in the yellowing process than the solder resist layer 32B. For example, the ultraviolet irradiation time in the solder resist layer 32C is set to twice that in the solder resist layer 32B. The chromaticity (yellowing degree) of the solder resist layer 32C is (x, y) = (0.33, 0.35) when expressed in terms of CIEYxy coordinate values. That is, the chromaticity (yellowing degree) of the solder resist layer 32C is set higher than the chromaticity (yellowing degree) of the solder resist layer 32B. The light reflectance in such a solder resist layer 32C is further lower than the light reflectance of the solder resist layer 32B. Note that the backlight device 12A of the present embodiment is used in a liquid crystal display device 10 as shown in FIGS.

As described above, the backlight device 12A according to the present embodiment is provided with the LED substrate 18 including the solder resist layer 32C at the center portion of the bottom plate 14a. Is further suppressed. This is because, in the backlight device 10 according to the first embodiment, the outer side and the inner side among the central portion (the portion surrounded by the peripheral portion of the light emitting portion 12a) of the light emitting portion 12a (see FIG. 2 of the first embodiment). And there is a difference in luminance. This brightness difference is less in comparison with the brightness difference between the peripheral part of the light emitting part 12a and the central part of the light emitting part 12a, which has been a problem in the first embodiment, but it is on the inside rather than the outside. The brightness is higher.

Therefore, in the present embodiment, by disposing the solder resist layer 32C having a low light reflectance at the center portion of the bottom plate 14a, the solder resist layer 32C (the solder resist layer 32C exposed from the lens insertion hole 21d) is reflected. Suppressed light. Therefore, the backlight device 12A according to the present embodiment further suppresses uneven brightness as compared with the first embodiment.

<Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG. In this embodiment, the backlight device 12B is illustrated. FIG. 11 is a plan view of the LED substrate 18 disposed on the bottom plate 14a of the chassis 14 included in the illumination device (backlight device) 12B of the third embodiment. In the backlight device 12B of the present embodiment, the solder resist layer 32 formed on each LED substrate 18 has a different configuration from that of the first embodiment.

In FIG. 11, similar to the first embodiment, six LED boards 18 are arranged in a row on the bottom plate 14 a of the chassis 14. However, unlike the first embodiment, the solder resist layer 32 formed on each LED substrate 18 has a yellowing degree in one solder resist layer 32 formed on one LED substrate 18. Two different types of solder resist

layers

32A and 32B are formed.

Each solder resist layer 32 on each LED substrate 18 is manufactured from a white solder resist as in the first embodiment. However, the white solder resist coating formed on each LED substrate 18 is partially subjected to yellowing treatment by ultraviolet irradiation. As shown in FIG. 11, when the bottom plate 14a of the chassis 14 is viewed in a plane, a solder resist layer 32B having a substantially elliptical shape (substantially oval shape) is formed in the center portion. This solder resist layer 32 B is formed across (strands) each solder resist layer 32 formed on the six LED substrates 18. A frame-shaped solder resist layer 32A is formed around the substantially elliptical solder resist layer 32B. The frame-shaped solder resist layer 32 A is also formed across (strands) the solder resist layers 32 formed on the six LED substrates 18.

In addition, the yellowing process of the solder resist layer 32 (white solder resist coating film) of each LED substrate 18 is performed using a mask having a predetermined shape that shields ultraviolet rays. The mask corresponds to the shape of the solder resist layer 32 A that is to be formed on the LED substrate 18. When the solder resist layer 32 (white solder resist coating film) on the LED substrate 18 is irradiated with ultraviolet rays through the mask, a yellow-shaped solder resist layer 32 having a predetermined shape is formed on the LED substrate 18. The

In addition, the range in which the solder resist

layers

32A and 32B are formed is determined based on predetermined luminance distribution data. For example, the brightness distribution data includes a backlight device in which all of the six LED boards 18 arranged on the bottom plate 14a of the chassis 14 are replaced with ones having a white solder resist layer 32 (32A). It is obtained by measuring the luminance distribution in the planar light emitted from the light emitting portion of the backlight device using a known luminance distribution measuring device. Based on the acquired luminance distribution data (for example, a two-dimensional image), a high luminance range and a low luminance range in the light emitting portion are determined, and based on the result, the solder resist layer 32 (white solder resist). The range to be yellowed can be determined. That is, the distribution of yellowing degree in the solder resist layer 32 can be determined.

As described above, by using the luminance distribution data, it is possible to accurately distinguish a portion where the reflected light from the solder resist layer 32 is desired to be increased and a location where the reflected light is desired to be decreased. As a result, the luminance unevenness of the backlight device 12B can be reliably suppressed.

As in this embodiment, a portion of the white solder resist layer 32 A having a high light reflectance and a yellowed solder resist layer having a low light reflectance so as to straddle the solder resist layers 32 on the plurality of LED substrates 18. The portion 32B may be formed in the chassis 14.

<Embodiment 4>
Next, Embodiment 4 of the present invention will be described with reference to FIGS. In the fourth embodiment, the backlight device 12 of the first embodiment described above is replaced with an edge light type backlight device 12C.

FIG. 12 is an exploded perspective view showing a schematic configuration of the liquid crystal display device 10C according to the fourth embodiment. As shown in FIG. 12, the liquid crystal display device 10 C according to the present embodiment has a configuration in which a liquid crystal panel 11 and an edge light type backlight device 12 C are integrated by a bezel 13 or the like. The configuration of the liquid crystal panel 11 is the same as that of the first embodiment. Hereinafter, the configuration of the edge light type backlight device 12C will be described.

As shown in FIG. 12, the backlight device 12C includes a chassis 14 having a substantially box shape having an opening 14b (light emitting portion) that opens on the front side, that is, the light emitting portion 12a side (the liquid crystal panel 11 side). The optical member 15 is disposed so as to cover the opening 14b of the chassis 14, and the frame 16 holds the light guide member 22 described below from the front side. Further, in the chassis 14, an LED substrate 18C (light source substrate) on which an LED (Light Emitting Diode) 17 as a light source is mounted, and the optical member 15 (the liquid crystal panel 11) is guided by the light from the LED 17. The light guide member 22 that leads to the light emitting part 12a side) is accommodated. And this backlight apparatus 12C is equipped with LED board 18C which has LED17 in the both ends of the long side, respectively, and is light guide member 20 in the center side pinched | interposed between LED board 18C distribute | arranged at both ends. Is a so-called edge light type (side light type).

The chassis 14 is made of a metal plate. As shown in FIG. 12, the chassis 14 has a horizontally long bottom plate 14a similar to the liquid crystal panel 11, and each side of the bottom plate 14a (a pair of long sides and a pair of short sides). Each side plate 14c rises from the outer end toward the front side. Further, the frame 16 and the bezel 13 can be screwed to the side plate 14c.

As shown in FIG. 12, the optical member 15 has a horizontally long rectangular shape when viewed in a plane, like the liquid crystal panel 11 and the chassis 14. The optical member 15 is placed on the front side (light emitting side) of the light guide member 22 and is interposed between the liquid crystal panel 11 and the light guide member 22. The optical member 15 includes a diffusion plate 15a disposed on the back side (the side opposite to the light guide member 22 side and the light emitting unit 12a side) and an optical disposed on the front side (the liquid crystal panel 11 side and the light emitting unit 12a side). And a sheet 15b. The diffusing plate 15a has a structure in which a large number of diffusing particles are dispersed in a translucent base material made of a substantially transparent synthetic resin having a predetermined thickness, and has a function of diffusing transmitted light. . The optical sheet 15b has a sheet shape that is thinner than the diffusion plate 15a, and three optical sheets are laminated. As the specific optical sheet 15b, for example, a diffusion sheet, a prism sheet, or a reflective polarizing sheet is used.

As shown in FIG. 12, the frame 16 is formed in a frame shape (frame shape) extending along the outer peripheral end portion of the light guide member 22, and the outer peripheral end portion of the light guide member 22 is almost entirely surrounded. It is possible to hold down from the front side. Further, the frame 16 can receive the outer peripheral end of the liquid crystal panel 11 from the back side.

13 and 14, the LED 17 has a configuration in which an LED chip is sealed with a resin material on a substrate portion fixed to the LED substrate 18C. As shown in FIG. 12, the LED substrate 18 C has a long plate shape extending along the long side direction of the chassis 14, and is a plate of the liquid crystal panel 11 and the light guide member 22 (optical member 15). It is accommodated in the chassis 14 in a posture orthogonal to the surface. That is, the LED substrate 18C has a posture in which the long side direction on the plate surface coincides with the X-axis direction, the short side direction coincides with the Z-axis direction, and the plate thickness direction orthogonal to the plate surface coincides with the Y-axis direction. It is said.

As shown in FIG. 12, the LED substrate 18 C is arranged in a pair at a position where the light guide member 22 is sandwiched in the Y-axis direction. Specifically, each of the long side sides of the light guide member 22 and the chassis 14 is arranged. They are respectively arranged so as to be interposed between the side plates 14c. Among the plate surfaces of the LED substrate 18C, a plurality (27 in this embodiment) of LEDs 17 are arranged on the inner side, that is, the surface facing the light guide member 22 side (a surface facing the light guide member 22) of the LED substrate 18C. They are arranged intermittently in parallel along the long side direction (the long side direction of the chassis 14, the X-axis direction). The LED 17 is surface-mounted on the surface of the LED substrate 18C facing the light guide member 22 side, and the surface is referred to as a plate surface on which the LED 17 is mounted (a plate surface on which a light source is mounted). On the plate surface on which the LEDs 17 are mounted, pattern wiring (not shown) made of a metal film (such as a copper foil) is formed that extends along the X-axis direction and connects the LEDs 17 in series. Terminal portions (not shown) are formed at both ends of the pattern wiring, and the terminal portions are connected to an external driving circuit, so that driving power can be supplied to each LED 17. Further, a white solder resist layer 32 (reflection layer) for protecting the wiring is laminated on the surface of the pattern wiring. The solder resist layer 32 will be described in detail later. As shown in FIG. 12, the pair of LED boards 18 C are respectively attached such that the plate surface opposite to the plate surface on which the LEDs 17 are mounted is in contact with the inner surfaces of the pair of side plates 14 c on the long side of the chassis 14. ing.

The light guide member 22 is made of a synthetic resin material (for example, acrylic or the like) having a refractive index sufficiently higher than air and substantially transparent (excellent translucency). As shown in FIG. 12, the light guide member 22 is formed in a plate shape that has a horizontally long rectangular shape in a plan view, like the liquid crystal panel 11 and the chassis 14, and the long side direction on the plate surface is the X axis. The direction and the short side direction coincide with the Y-axis direction, respectively, and the plate thickness direction orthogonal to the plate surface coincides with the Z-axis direction. As shown in FIG. 13, the light guide member 22 is disposed in the chassis 14 at a position immediately below the liquid crystal panel 11 and the optical member 15, and forms a pair disposed at both ends of the long side of the chassis 14. The LED boards 18C are arranged so as to be sandwiched between the Y-axis directions. Then, the light guide member 22 introduces light emitted from the LED 17 in the Y-axis direction, and rises toward the optical member 15 side (front side, light emission side) while propagating the light inside. It has a function to emit light.

Of the plate surface of the light guide member 22, the surface facing the front side is a light emitting surface 22 b that emits internal light toward the optical member 15 and the liquid crystal panel 11. Of the outer peripheral end surfaces adjacent to the plate surface of the light guide member 22, both end surfaces on the long side which are long along the X-axis direction are respectively LEDs 17 (LED substrates 518) as shown in FIG. And are opposed to each other with a predetermined space therebetween, which constitute a light incident surface 22a on which light emitted from the LED 17 is incident.

Of the plate surface of the light guide member 22, the surface 22c opposite to the light exit surface 22b can reflect the light in the light guide member 22 and rise to the front side as shown in FIG. A reflective optical member 25 is provided so as to cover the entire area. Note that a scattering portion (not shown) that scatters light in the light guide member 22 is formed on at least one of the light exit surface 22b and the opposite surface 22c of the light guide member 22 or on the surface of the reflective optical member 25. ) And the like are patterned so as to have a predetermined in-plane distribution, and thereby, the emitted light from the light emitting surface 22b is controlled to have a uniform distribution in the surface.

The solder resist layer 32 provided on the LED substrate 18C will be described. The same solder resist layer 32 as in the first embodiment is used. As shown in FIG. 14, the solder resist layer 32 is provided over substantially the entire plate surface (mounting surface) of the LED substrate 18 C except for the portion where the LED 17 is mounted. The solder resist layer 32 faces the light incident surface 22a of the light guide member 22, and is located between the light incident surface 22a of the light guide member 22 and the base material of the LED substrate 18C. Therefore, among the light emitted from the LED 17 toward the light guide member 22, the solder resist layer 32 is directed again toward the light guide member 22 for the light returned from the light guide member 22 side to the LED substrate 18 C side. Can be reflected.

The yellowing degree (light reflectance) of the solder resist layer 32 in the LED substrate 18C is sandwiched between both end portions 181C and both end portions 181C in the long side direction (long side direction of the chassis 14, X-axis direction) of the LED substrate 18C. The center portion 182C is different. The solder resist layer 32 at the end portion 181C is made of a white solder resist layer 32A, and the solder resist layer 32 at the center portion 182C is made of a yellowed solder resist layer 32B. That is, the yellowing degree of the central part 182C is set higher than the yellowing degree of the end part 182C, and the light reflectance of the end part 181C is relatively higher than the light reflectance of the central part 182C. It is said that. Note that the solder resist

layers

32A and 32B of the present embodiment are made of the same type as in the first embodiment.

Even in the edge light type backlight device 12C as in the present embodiment, many LEDs 17 cannot be arranged on both ends 181C side of the LED substrate 18C. In particular, when connectors for supplying external power to the respective LEDs 17 are provided at both ends of the LED substrate 18C, the space for disposing the LEDs 17 on both ends 181C of the LEDs 17 is limited. Therefore, when only the light supplied directly from the LED 17 into the light guide member 22 is considered, both end portions on the short side of the light emitting portion 12a are sandwiched between them (the central portion of the light emitting portion 12a). Compared to the above, the luminance is lowered.

However, as described above, in the present embodiment, the light reflectance at both end portions 181C of the LED substrate 18C is set higher than the light reflectance at the central portion 182C, so the solder resist layer 32B of the central portion 182C is used. Light reflection is suppressed and light reflection is promoted by the solder resist layer 32A at both ends 181C. As a result, a large amount of reflected light from the solder resist layer 32 is incident on the light incident surfaces 22a at both ends of the long light incident surface 22a of the light guide member 22. That is, the shortage of light quantity at both ends on the short side of the light emitting part 12a is compensated by the reflected light from the solder resist layer 32B. Therefore, also in the backlight device 12C of the present embodiment, luminance unevenness of the light emitting unit 12a is suppressed.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

(1) In the first embodiment and the like, the example including the diffusing lens 19 is illustrated, but in another embodiment, the diffusing lens 19 may not be provided.

(2) In the first embodiment and the like, the white solder resist layer 32A is used as the solder resist layer 32 disposed on the end side of the chassis 14. In other embodiments, for example, the solder resist layer 32A in the first embodiment may be replaced with the solder resist layer 32B, and the solder resist layer 32B in the first embodiment may be replaced with the solder resist layer 32C (see the second embodiment). Good. In short, in the present invention, the yellowing degree of the solder resist layer 32 provided at the location where the reflected light is desired to be promoted in the chassis 14 is more than the yellowing degree of the solder resist layer 32 provided at the location where the reflected light is desired to be suppressed. May be set relatively low.

(3) In the first embodiment or the like, it is also possible to use an insulating material such as ceramic as an example of the base material 30 of the LED substrate 18 that is made of a metal such as the same aluminum material as the chassis 14.

(4) In Embodiment 1 or the like, the one provided with the reflective sheet 21 is shown, but in other embodiments, a configuration without the reflective sheet may be used.

(5) In Embodiment 1 or the like, an example using the LED 17 as the light source is illustrated, but in other embodiments, a light source other than the LED may be used.

(6) Although the TFT is used as the switching element of the liquid crystal display device in the first embodiment and the like, the liquid crystal display device using a switching element other than the TFT (for example, a film diode (TFD)) is used in other embodiments. In addition to a liquid crystal display device that performs color display, the present invention can also be applied to a liquid crystal display device that performs monochrome display.

(7) In the first embodiment and the like, a liquid crystal display device using a liquid crystal panel as a display panel has been exemplified, but in other embodiments, a display device using another type of display panel may be used.

(8) In the first embodiment and the like, the television receiver provided with the tuner is illustrated, but the display device according to the other embodiment may not include the tuner.

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device (display device), 11 ... Liquid crystal panel, 12 ... Backlight device (illumination device), 13 ... Bezel, 14 ... Chassis, 15 ... Optical member, 16 ... Frame, 17 ... LED (light source), 18 DESCRIPTION OF SYMBOLS ... LED board (light source board), 19 ... Diffusing lens, 20 ... Support member, 21 ... Reflective sheet, 22 ... Light guide member, 32 ... Solder resist layer, 32A ... White solder resist layer, 32B ... Yellowed solder Resist layer

Claims

One or more light sources;
A light source substrate on which the light source is mounted;
A chassis in which the light source substrate is disposed on the plate surface, which is a plate-like member;
A reflection layer disposed on the light source substrate, and when viewed from the entire plate surface of the chassis, is more central than a portion located on the end portion side than a portion located on the end portion side of the chassis. And a reflective layer that is formed with a relatively high degree of yellowing in a portion located on the part side.
The illuminating device according to claim 1, wherein the reflective layer is formed of a solder resist layer that increases in yellowing degree when irradiated with ultraviolet rays.
A lens member for diffusing light, comprising a lens member disposed on the plate surface of the light source substrate and covering a light emitting side of the light source;
The lighting device according to claim 1, wherein the reflective layer is formed at least in a portion overlapping with the lens member.
A reflection sheet for reflecting light, having an opening that is opened larger than the outer shape of the lens member, allowing the lens member to pass through the opening and being disposed on the plate surface of the light source substrate. With a reflective sheet,
The lighting device according to claim 3, wherein the reflective layer is formed at least in a portion exposed from the opening.
When the reflective layer is entirely replaced with a white solder resist layer that is not yellowed, the distribution of yellowing degree in the reflective layer is determined based on the luminance distribution of planar light emitted from the light source. The illumination device according to any one of claims 1 to 4.
The difference between the light reflectance of the portion located on the end side of the reflective layer and the light reflectance of the portion located on the center side of the reflective layer is 5% or more. The lighting device according to claim 5.
The chassis has a light emitting portion that emits light from the light source,
An optical member disposed so as to cover the light emitting portion;
The optical member has at least one of a diffusion plate having a function of diffusing light from the light source, a function of collecting light transmitted through the diffusion plate, and a function of diffusing light transmitted through the diffusion plate. An illumination device according to any one of claims 1 to 6, comprising an optical sheet having a function.
The illumination device according to any one of claims 1 to 7, wherein the light source includes a light emitting diode.
A display device comprising: the illumination device according to any one of claims 1 to 8; and a display panel that performs display using light from the illumination device.
The display device according to claim 9, wherein the display panel is a liquid crystal panel in which liquid crystal is sealed between a pair of substrates.
A television receiver comprising the display device according to claim 9 or 10.