Backlight device and liquid crystal display device

The backlight device includes a plurality of packages, and a light guide plate. The package includes a housing for package, and a plurality of light sources. The housing for package includes a tubular part having a wall surrounding the circumference, a bottom wall provided at one end of the tubular part, and a passing part provided at the other end of the tubular part for passing the light from inside to outside of the tubular part. The plurality of light sources are contained in the housing for package and disposed in the bottom wall, and emit light. The plurality of packages are arrayed in one direction. At least part of the layout of light sources relative to the incident plane is different from mutually adjacent packages.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Applications No. 2007-000199, filed Jan. 4, 2007; and No. 2007-327655, filed Dec. 19, 2007, the entire contents of both of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sidelight type backlight device used in, for example, a liquid crystal display or other liquid crystal display devices. The invention also relates to a liquid crystal display device provided with a backlight device.

2. Description of the Related Art

Conventionally, in a display for electronic appliances such as a portable computer, for example, a liquid crystal display is used in consideration of portable use. The liquid crystal display is composed of a liquid crystal panel, which is a non-luminous display device. Accordingly, the liquid crystal display device has a backlight device for illuminating the liquid crystal panel.

A portable electronic appliance is reduced in thickness. Hence, a sidelight type is used as the backlight device.

The sidelight type backlight device is generally provided with a light source and a light guide plate for guiding the light emitted from the light source to an entire liquid crystal panel region. An incident plane which receives the light emitted from the light source is formed at a side face of the light guide plate. An exit plane which emits the incident light from the incident plane is formed at an upper part of the light guide plate. The light source is, for example, a fluorescent lamp. The light source is disposed near the incident plane. This kind of backlight device is disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 10-40872.

Other backlight device uses a light-emitting diode (LED) as the light source. In this kind of backlight device, a red, blue, and green LED are contained in one housing to serve as an LED package, and a plurality of LED packages may be used.

When the red, blue and green LEDs are housed in one package, red, blue, and green are mixed. As a result, the light emitted from the LED package is white.

In a specific structure of the LED package thus configured, the LED package includes the housing, red, blue, and green LEDs.

The housing is made of a resin having enough reflectivity for mixing the colors of the light components emitted from the LEDs efficiently, and is formed in a so-called bathtub structure having a vertical wall surrounding the circumference. The LEDs are contained in the housing, and are disposed in a substantially triangular shape linking the LEDs so that the colors of the light components emitted from the LEDs may be mixed efficiently. The inside of the housing is sealed with a permeable resin so that the light components emitted from the LEDs may escape outside.

The LED packages are arranged in a row so that the positions sealed with the permeable resin (the inside openings surrounded by the vertical wall) may be directed to the incident plane of the light guide plate within the housing.

However, in the backlight device formed of plural LED packages having such configuration and arranged in one row, color fluctuation is likely to occur on the light guide plate. This point will be more specifically explained below.

As mentioned above, the housing of the LED package is a bathtub structure. Each LED is disposed to form a substantially triangular shape linking these LEDs. Accordingly, each LED is disposed at a position slightly shifted to either vertical wall in the housing.

As a result, in a plan view of LEDs (when the backlight device is seen from above), any of the LEDs is shifted to one side of the LED package array direction. For example, when the red LED is shifted to one side of the LED package array direction, the shape of the illumination range when the illumination range of red light emitted from the LED package is seen in a plan view is defined by a line linking the red LED in the LED package array direction in the vertical wall of the housing and the red LED close to it, and a line linking the red LED in the LED package array direction in the vertical wall and the red LED remote from it. The shape of the thus defined illumination range is a shape biased to the other side of the LED array direction.

To the contrary, in a plan view of the LED package, the shape of the illumination range of the LED, for example, a blue LED arranged at the opposite side of the red LED in the LED package array direction is biased to one side.

Hence, at one side of the LED package array direction, the red light hardly reaches the vicinity of the LED package, and at the other side, the blue right hardly reaches the vicinity of the LED package.

As a result, in the light guide plate, at one side of the LED array direction, the rate of blue light is higher, thus making color mixing difficult, and uneven color is likely to occur. Similarly, in the light guide plate, at the other side of the LED array direction, the rate of red light is higher, thus making color mixing difficult, and uneven color is likely to occur.

In the above explanation, the red and blue LEDs are spaced from each other in the LED array direction, but this is not a limited example. Uneven color is likely to occur if any one of the plural LEDs contained in the housing is biased to any position of the vertical wall.

BRIEF SUMMARY OF THE INVENTION

It is hence an object of the invention to provide a backlight device capable of suppressing uneven color on the light guide plate. It is another object of the invention to provide a liquid crystal display device provided with a backlight device capable of suppressing uneven color on the light guide plate.

The backlight device of the invention comprises a plurality of packages and a light guide plate. The light guide plate includes an incident plane which receives the light emitted from the package, and an exit plane which emits the incident light from the incident plane to outside. Said plurality of packages are arrayed in one direction. The package includes a housing for package, and a plurality of light sources. The housing for package includes a tubular part having a wall surrounding the circumference, a bottom wall provided at one end of the tubular part, and a passing part provided at the other end of the tubular part for allowing the light to be transmitted from the inside of the tubular part to outside. Said plurality of light sources are contained in the housing for package and disposed in the bottom wall, and are designed to emit light. At least a part of the arrangement of the light sources with respect to the incident plane is different from the adjacent packages.

The liquid crystal display device of the invention comprises a housing for liquid crystal display device, a liquid crystal panel, and a backlight device. The liquid crystal panel is contained in the housing for liquid crystal display device. The backlight device is contained in the housing for liquid crystal display device. The backlight device has a plurality of packages and a light guide plate. The light guide plate has an incident plane which receives the light emitted from the package, and an exit plane which emits the incident light from the incident plane to outside. Said plurality of packages are arrayed in one direction. The package includes a housing for package, and a plurality of light sources. The housing for package includes a tubular part having a wall surrounding the circumference, a bottom wall provided at one end of the tubular part, and a passing part provided at the other end of the tubular part for allowing the light to be transmitted from the inside of the tubular part to outside. Said plurality of light sources are contained in the housing for package, and disposed in the bottom wall and are designed to emit light. At least part of the arrangement of the light sources with respect to the incident plane is different from the adjacent packages.

DETAILED DESCRIPTION OF THE INVENTION

A backlight device according to a first embodiment of the invention is described while referring toFIGS. 1 to 10.FIG. 1is a partially exploded perspective view of a portable Digital Versatile Disc (DVD) player10provided with a backlight device20of the embodiment. The portable DVD player10is an example of an electronic appliance provided with the backlight device20. The backlight device20may be also used in other electronic appliances such as portable telephone.

As shown inFIG. 1, the portable DVD player10includes a main body11, and a liquid crystal display device12. The main body11accommodates a disc not shown. The liquid crystal display device12is attached to the main body11, and is designed to display images.

FIG. 1shows a disassembled state of the liquid crystal display device12. The liquid crystal display device12includes a first housing13, a liquid crystal panel14, and the backlight device20. The liquid crystal panel14and the backlight device20are contained in the first housing13. The first housing13is an example of the housing for liquid crystal display device of the invention.

While the liquid crystal display device12is standing upright to the main body11, a opening15is formed in a front wall13aof the first housing13directed forward. The first housing13is rotatably coupled to the main body11between the exposed position of the opening15and the closed position of the opening15. The liquid crystal panel14has a screen16. The screen16is exposed outside of the first housing13by way of the opening15. InFIG. 1, the first housing13is separated from the front wall13a, but this is not a limited example. Anyway, the first housing13may be designed to incorporate therein the liquid crystal panel14and the backlight device20.

The backlight device20is disposed at the opposite side of the opening15across the liquid crystal panel14, and confronts the liquid crystal panel14. The backlight device20illuminates the liquid crystal panel14.FIG. 2is a plan view of the backlight device20seen from above.FIG. 3is a sectional view of the backlight device20shown along line F3-F3inFIG. 2. InFIG. 3, the liquid crystal panel14is indicated by twin-dot chain line. A relative positional relation between the liquid crystal panel14and the backlight device20inFIG. 3is similar to a relative positional relation between the liquid crystal panel14and the backlight device20in the first housing13.

As shown inFIGS. 2 and 3, the backlight device20includes a second housing21, a light guide plate22, a reflection sheet23, a diffusion sheet24, a light guide25, and a light source unit30.

As shown inFIG. 3, the second housing21is a box opened at the liquid crystal panel14side and closed at the bottom. The second housing21has a bottom wall26and a vertical wall27. The bottom wall27has a substantially rectangular plane shape. The vertical wall27is erected upright from the entire region of the peripheral edge of the bottom wall26. Hence, the plane shape of the inside space defined by the vertical wall27and the bottom wall27is substantially rectangular.

The light guide plate22is contained in the second housing21. As shown inFIG. 3, the light guide plate22guides the light emitted from the light source unit30described below into the liquid crystal panel14. The light guide plate22has an incident plane28and an exit plane29. The incident plane28is formed at the side face of the light guide plate22, and confronts the inside of the second housing21. The incident plane28receives the light emitted from the light source unit30. The exit plane29is formed at a position opposite to the liquid crystal panel14in the light guide plate22. The exit plane29emits the incident light from the incident plane29toward the liquid crystal panel14.

The reflection sheet23is provided at the inside of the bottom wall26, and confronts the light guide plate22. The diffusion sheet24is disposed between the light guide plate22and the liquid crystal panel14. The light guide25is disposed between the incident plane28of the light guide plate22and the light source unit30.

FIG. 4is a sectional view of the backlight device20shown along line F4-F4inFIG. 3.FIG. 4shows a front view of the light source unit30. As shown inFIGS. 2,3and4, the light source unit30is disposed at a position confronting the incident plane28of the light guide plate22at the inside of the second housing21, and is designed to emit light to the incident plane28. InFIG. 4, the incident plane28is indicated by twin-dot chain line. The light source unit30includes a substrate31and a plurality of LED packages32.

As shown inFIGS. 2 and 3, the substrate31is fixed at a position confronting the incident plane28of the light guide plate at the inside of the second housing21. As shown inFIG. 4, the LED packages32are arranged in a row on the substrate31. A specific configuration of the LED packages32on the substrate31will be described in detail below.

FIG. 5is a magnified front view of the range of F5shown inFIG. 4.FIG. 5is a front view of one LED package32. As shown inFIG. 5, the LED package32includes a third housing33, a red LED34, a blue LED35, and a green LED36. The LED packages32are identical in structure, and one LED package is shown as a structural example.

FIG. 6is a sectional view of the LED package32shown along line F6-F6inFIG. 5. As shown inFIG. 6, the third housing33includes a housing main body37of box type opened at one end, and a sealing part38. The third housing33is an example of the housing for package of the invention.

The housing main body37has a bottom wall39and a vertical wall40. As shown inFIG. 5, the bottom wall39has a substantially rectangular plane shape. The vertical wall40is erected upright from the entire region of the peripheral edge of the bottom wall39. Hence, the vertical wall40is tubular, and the plane shape of the inside space of the housing main body37defined by the vertical wall40is substantially rectangular. The vertical wall40is an example of the tubular part of the invention. The housing main body37is formed of an impermeable resin and does not pass light from inside to outside.

The red LED34emits a red light. The blue LED35emits a blue light. The green LED36emits a green light. The red LED34, blue LED35, and green LED36are contained inside the housing main body37. The plane shape of the red LED34, blue LED35, and green LED36is, for example, rectangular. The LEDs34,35,36are disposed to form a substantially triangular shape mutually, and are fixed to the bottom wall39.

The layout of the LEDs34,35,36will be more specifically described. The vertical wall40has a first inner face41, a second inner face42, a third inner face43, and a fourth inner face44. The first inner face41is positioned at an upper side inFIG. 5. The second inner face42is positioned at a right side in the drawing. The third inner face43is positioned at a lower side inFIG. 5. The fourth inner face44is positioned at a left side inFIG. 5.

The red LED34is disposed near an angle45defined by the second inner face42and the third inner face43. The blue LED35is disposed near an angle46defined by the third inner face43and the fourth inner face44. The red LED34and the blue LED35are placed side by side along the third inner face43. The green LED36is placed between the first inner face41and the red LED34and blue LED35, and is disposed at a position confronting the center of the first inner face41.

In other words, the inner face positioned near the green LED36is the first inner face41, the inner faces positioned near the red LED34are the second and third inner faces42,43, and the inner faces positioned near the blue LED35are the third and fourth inner faces43,44. Thus, in each LED package32, the LEDs34,35,36have an identical layout pattern.

FIG. 6is a sectional view of the red LED34and the blue LED35as seen from the first inner face41.FIG. 7is a sectional view of the LED package32shown along line F7-F7inFIG. 5.FIG. 7is a sectional view of the LED package32of the green LED36as seen from the third inner face43.

As shown inFIGS. 6 and 7, the green LED36, the red LED34, and the blue LED35are electrically connected to the substrate31by way of a wiring47.

As shown inFIG. 6, the sealing part38seals the inside of the housing main body37. The sealing part38is permeable, and the exit light components from the LEDs34,35,36are not prevented from escaping to outside from the opening48of the housing main body37. The sealing part38is formed of transparent or diffusible epoxy or silicone resin, and functions as the passing part of the invention. InFIGS. 6 and 7, the sealing part38is not indicated with hatchings.

The layout and position of the LED packages32on the substrate31will be explained. In the embodiment, as shown inFIGS. 2 and 4, for example, five LED packages32are used. InFIG. 2, the LED package32and the substrate31are shown in partially cut-off state. In each LED package32, the sealing part38is fixed on the substrate31so as to confront the incident plane28of the light guide plate22, and the LED packages32are arranged in a row along the incident plane28.

As shown inFIG. 4, configurations of the mutually adjacent LED packages32on the substrate31are different. Specifically speaking, the LED package32disposed at one end50in the drawing (one end of array direction of LED packages32) is disposed so that, for example, the green LED36may be directed to the opening49side of the second housing21.

The positions of the other LED packages32rotate 180 degrees about an axial center line52of the housing main body37along with shift to the side of the other end51(other end of array direction of LED packages32). The axial center line52is indicated by a dot in the drawing. That is, the mutually adjacent LED packages32in the array direction of the LED packages32are disposed at positions rotating 180 degrees relatively about the axial center line52of the third housing33. Hence, in the light source unit30, the LED packages32are arranged so that the first inner face41and the third inner face43may be arranged alternately at the side of the opening49of the second housing21.

As a result, the layout of the LEDs34,35,36in each LED package32with respect to the incident plane28is designed to be different mutually between the adjacent LED packages32.

The light components emitted from the LED packages32in such configuration (the light components passing through outside from the sealing part38out of the light components emitted from the green LED36, red LED34, and blue LED35) are emitted to the incident plane28of the light guide plate22.

The next explanation is about the shape of the illumination range of the light components of the LEDs34,35,36emitted outside through the sealing part38as seen from the side of the opening49of the second housing21. As stated above, in each LED package32, any one of the first inner face41and the third inner face43is positioned at the side of the opening49.

Accordingly, the shape of the illumination range of the light components emitted from each LED package32as seen from the side of the opening49is the same as the shape of the light emitted from each LED package32seen from the first inner face41. The first inner face41and the third inner face43are opposite to each other. Therefore, the shape of the illumination range of the light components emitted from the LED packages32as seen from the side of the third inner face43is same as the shape as seen from the side of the first inner face41.

FIG. 7shows the shape of the illumination range of the green LED36as seen from the side of the third inner face43. The shape of the illumination range of the green LED36emitted from the LED package as seen from the side of the third inner face43is defined by first and second lines55,56linking the green LED36and edges53,54of the second and fourth inner faces42,44. The illumination range is the area enclosed by the first and second lines55,56.

As shown inFIG. 7, the green LED36is disposed at a position confronting nearly the center of the first and third inner faces41,43as mentioned above. Hence, the first line55linking the green LED36and the edge53of the second inner face42, and the second line56linking the green LED36and the edge54of the fourth inner face44are mutually symmetrical across the green LED36.

As a result, the shape of the illumination range of the green LED36emitted from the LED package32as seen from the side of the third inner face43is a shape spreading outside similarly at both sides of the second and fourth inner faces42,44. Herein, “outside” means the direction toward the second and fourth inner faces42,44from the green LED36.

FIG. 6shows the shape of the illumination range of the red LED34and the blue LED35as seen from the side of the first inner face41. The shape of the illumination range of the red LED34as seen from the side of the first inner side41is defined by third and fourth lines57,58linking the red LED34and the edges53,54of the second and fourth inner faces42,44. The illumination range is the area enclosed by the third and fourth lines57,58. The third and fourth lines57,58are indicated by single-dot chain line.

As shown inFIG. 6, the red LED34is disposed at a position close to the second inner face42as mentioned above. Hence, as compared with the third line57linking the red LED34and the edge53of the second inner face42, the fourth line58linking the red LED34and the edge54of the fourth inner face44is largely inclined. As a result, the shape of the illumination range of the red LED34as seen from the side of the first inner face41is a shape biased to the side of the fourth inner face44.

The shape of the illumination range of the blue LED35as seen from the side of the first inner face41is defined by fifth and sixth lines59,60linking the blue LED35and the edges53,54of the second and fourth inner faces42,44. The illumination range is an area enclosed by the fifth and sixth lines59,60. The fifth and sixth lines59,60are indicated by dotted line.

As shown inFIG. 6, the blue LED35is disposed at a position close to the fourth inner face44as mentioned above. Hence, as compared with the sixth line60linking the blue LED35and the edge54of the fourth inner face44, the fifth line59linking the blue LED35and the edge53of the second inner face42is largely inclined. As a result, the shape of the illumination range of the blue LED35as seen from the side of the first inner face41is a shape biased to the side of the second inner face42.

Among the light components of the LEDs34,35,36emitted from the LED packages32, distribution of the light components entering the light guide25and the light guide plate22will be explained.

FIG. 8shows an example of distribution of green light emitted from each LED package32in the light guide25and the light guide plate22. InFIG. 8, light components reflected by the light guide25and the light guide plate22are not shown. InFIG. 8, for the ease of understanding the position of the green LED36in relation to the LED package32and the substrate31, a partially cut-off state is shown. As shown inFIG. 8, the green LED36is disposed at a position confronting nearly the center of the first and third inner faces41,43, and the guide light25and the light guide plate22are illuminated almost uniformly.

The green light emitted from each LED package32is considered to reach the end of the light source unit30side at the one end50and the other end51of the light guide plate22. Specifically, the relative shape and relative position of the third housing33and the green LED36are taken into consideration. For example, the position of the edges53,54of the vertical wall40of the third housing33relative to the position of the green LED36is taken into consideration.

FIG. 9shows an example of distribution of red light emitted from each LED package32in the light guide25and the light guide plate22. InFIG. 9, light components reflected by the light guide25and the light guide plate22are not shown. As shown inFIG. 9, the LED package32disposed at the one end50is disposed at a position of the fourth inner face44being shifted closer to the side of the other end51. Hence, the illumination range of the red light emitted from the LED package32disposed at the one end50is biased to the side of the fourth inner side44, that is, to the side of the other end51.

The LED package32disposed at one position shifted to the side of the other end51is disposed at a position so that the second inner face42is shifted to the other end51side. Hence, the illumination range of the red light emitted from the LED package32is biased to the one end50side.

The LED package32disposed at one position further shifted to the side of the other end51is disposed at a position so that the second inner face42is shifted to the one end50side. Hence, the illumination range of the red light emitted from the LED package32is biased to the one end50side.

The LED package32disposed at one position further shifted to the side of the other end51is disposed at a position so that the second inner face42is shifted to the other end51side. Hence, the illumination range of the red light emitted from the LED package32is biased to the other end51side.

The LED package32disposed at the other end51is disposed so that the second inner face42is shifted to the one end50side. Hence, the illumination range of the red light emitted from the LED package32is biased to the other end51side.

The red light components emitted from the LED package32are considered to illuminate up to the other end portion of the light source unit30at the one end50and the other end51of the light guide plate22, in such a manner that the mutually adjacent packages32are disposed at positions rotating mutually by 180 degrees. Specifically, the relative shape and relative position of the third housing33and the red LED34are taken into consideration. Specific examples are positions of the edges53,54of the vertical wall40of the third housing33relative to the position of the red LED34.

Thus, the red light components emitted from the LED packages32are alternately biased to the one end50side and the other end51side, and as a result, the red light components reach up to the one end50side and the other end51side near the light source unit30side in the light guide plate22.

Although not shown in the drawing, as the red light components emitted from the LED packages32are reflected, the red light components reach further into the light guide plate22.

FIG. 10shows an example of distribution of blue light emitted from each LED package32in the light guide25and the light guide plate22. InFIG. 10, light components reflected by the light guide25and the light guide plate22are not shown. As shown inFIG. 10, the LED package32disposed at the one end50is disposed at a position of the second inner face42being shifted closer to the side of the one end50. Hence, the illumination range of the blue light emitted from the LED package32disposed at the one end50is biased to the side of the one end50.

The LED package32disposed at one position shifted to the side of the other end51is disposed at a position so that the second inner face42is shifted to the other end51side. Hence, the illumination range of the blue light emitted from the LED package32is biased to the other end51side.

The LED package32disposed at one position further shifted to the side of the other end51is disposed at a position so that the second inner face42is shifted to the one end50side. Hence, the illumination range of the blue light emitted from the LED package32is biased to the one end50side.

The LED package32disposed at one position further shifted to the side of the other end51is disposed at a position so that the second inner face42is shifted to the other end51side. Hence, the illumination range of the blue light emitted from the LED package32is biased to the other end51side.

The LED package32disposed at the other end51is disposed so that the second inner face42is shifted to the one end50side. Hence, the illumination range of the blue light emitted from the LED package32is biased to the one end50side.

The blue light components emitted from the LED package32are considered to illuminate up to the other end portion of the light source unit30at the one end50and the other end51of the light guide plate22, in such a manner that the mutually adjacent packages32are disposed at positions rotating mutually by 180 degrees. Specifically, the relative shape and relative position of the third housing33and the blue LED35are taken into consideration. Specific examples are positions of the edges53,54of the vertical wall40of the third housing33relative to the position of the blue LED35.

Thus, the blue light components emitted from the LED packages32are alternately biased to the one end50side and the other end51side, and as a result, the blue light components reach up to the one end50side and the other end51side near the light source unit30side in the light guide plate22.

Although not shown in the drawing, as the blue light components emitted from the LED packages32are reflected, the blue light components reach further into the light guide plate22.

As mentioned above, the red light, blue light, and green light reach sufficiently into the vicinity of the light source unit30at the one end50and the other end51of the light guide plate22. As a result, in the light guide plate22, the red light, blue light, and green light are mixed uniformly.

Thus, in the backlight device20having such configuration, the positions of the LEDs34,35,36of the LED packages32with respect to the incident plane28of the light guide plate22are different in the mutually adjacent LED packages32. For example, in this embodiment, even if there is deviation in the illumination range of the red LED34or the illumination range of the blue LED35in the LED packages32, such deviation scatters, and thus the light of each color is sufficiently sent into the light source unit30side end near the one end50and the light source unit30side end near the other end51in the light guide plate22. Accordingly, in the light guide plate22, light components of the respective colors are mixed sufficiently in the light source unit30side end near the one end50and the light source unit30side end near the other end51, and thus uneven color hardly occurs on the light guide plate22(on the exist plane29).

In the embodiment, the layout of the LEDs34,35,36of the LED packages32with respect to the incident plane28is different among mutually adjacent LED packages32. Hence, colors are mixed more efficiently on the light guide plate22, and thus uneven color hardly occurs.

The LED packages32are identical in structure, having the same layout pattern of the LEDs34,35,36. The mutually adjacent LED packages32are disposed at relatively rotated positions around the axial center line52. As a result, the layout of the LEDs34,35,36of the mutually adjacent LED packages32with respect to the incident plane28is mutually different.

Thus, when fixing the LED packages32on the substrate31, it is enough to adjust the position of the LED packages32. Therefore, by using the LED packages32of identical structure, the structure of the entire apparatus becomes simple, and occurrence of uneven color on the light guide plate22can be suppressed.

Further, by fixing the mutually adjacent LED packages32at positions of relative rotation of 180 degrees, deviation of the illumination range of the red light and deviation of the illumination range of the blue light are exchanged alternately. As a result, occurrence of uneven color on the light guide plate22can be suppressed more effectively.

A backlight device20according to a second embodiment of the invention will be described below by referring toFIG. 11. The same parts as those in the first embodiment are denoted by the same reference numbers and explanation thereof is omitted. This embodiment is different from the first embodiment in the relative rotation angle of the adjacent LED packages32around the axial center line52. The other structure may be the same as in the first embodiment. The different points mentioned above will be specifically described below.

FIG. 11is a front view of a light source unit30in the embodiment. As shown inFIG. 11, in this embodiment, the adjacent LED packages32are disposed at positions of relative rotation of 90 degrees. The rotating direction of the LED packages32is the same direction. Also in this embodiment, since deviation of light components emitted from the LEDs34,35,36is scattered, the same effects as those in the first embodiment may be obtained.

A backlight device20according to a third embodiment of the invention will be described below by referring toFIG. 12. The same parts as those in the first embodiment are denoted by the same reference numbers and explanation thereof is omitted. This embodiment is different from the first embodiment in the relative rotation angle of the adjacent LED packages32around the axial center line52. The other structure may be the same as in the first embodiment. The different points mentioned above will be specifically described below.

FIG. 12is a front view of a light source unit30in the embodiment. As shown inFIG. 12, in this embodiment, the adjacent LED packages32are disposed at positions of relative rotation of 30 degrees. The rotating direction of the LED packages32is the same direction. Also in this embodiment, since deviation of light components emitted from the LEDs34,35,36is scattered, the same effects as those in the first embodiment may be obtained.

A backlight device20according to a fourth embodiment of the invention will be described below by referring toFIG. 13. The same parts as those in the first embodiment are denoted by the same reference numbers and explanation thereof is omitted. This embodiment is different from the first embodiment in the relative rotation angle of the adjacent LED packages32around the axial center line52. The other structure may be the same as in the first embodiment. The different points mentioned above will be specifically described below.

FIG. 13is a front view of a light source unit30in the embodiment. As shown inFIG. 13, in this embodiment, the adjacent LED packages32are disposed at positions of relative rotation of 60 degrees. The rotating direction of the LED packages32is the same direction. Also in this embodiment, since deviation of light components emitted from the LEDs34,35,36is scattered, the same effects as those in the first embodiment may be obtained.

In the first to fourth embodiments, the LED packages32have their opening48sealed by the sealing part38, but the structure is not limited to this example. For example, the opening48may not be sealed by the sealing part38. In this case, the opening48is the passing part of the invention.

In the first to fourth embodiments, the adjacent LED packages32rotate by 180 degrees, 90 degrees, 30 degrees, and 60 degrees, respectively, but the angles are not limited thereto. The adjacent LED packages32may rotate in the same direction around the axial center line52by 120 degrees, 150 degrees, 210 degrees, 240 degrees, 270 degrees, 300 degrees, or 330 degrees. Also in these examples, the same effects as those in the first to fourth embodiments may be obtained.

In short, when the adjacent LED packages32rotate about the axial center line52by 30×n degrees (n being 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11), the same effects as those in the first to fourth embodiments may be obtained.

In the first to fourth embodiments, the package32includes three light sources (green LED36, red LED34, and blue LED35), without being limited to this example. For example, it may include four light sources. In such a case, for example, it may include one red LED34, one blue LED35, and two green LEDs36.