Patent Application
20120224107
The present invention relates to a backlight device, a display device and a television receiver. More particularly, the invention relates to a backlight device, a display device and a television receiver that incorporate a substrate on which point light sources are mounted and connectors which are provided on the substrate.
Conventionally, as a backlight device that applies light to a display panel, a backlight device is known that incorporates substrates on which point light sources are mounted and connectors which are provided on the substrates.
The conventional backlight device includes: a plurality of substrates on which a plurality of LEDs (light-emitting diodes (point light sources)) are mounted; connectors which are arranged on the substrates and which electrically connect the substrates; reflective members such as a reflective sheet arranged in a predetermined region on the substrates; and optical sheets such as a diffusion sheet arranged on the light emitting side of the LEDs. In the backlight device described above, a plurality of opening portions are formed in the reflective members, and the LEDs and the connectors are electrically connected to the substrates through these opening portions.
Here, since the light reflectance of the surface of the connector is generally lower than that of the surface of the reflective member, loss of light is produced on the surface of the connector. Specifically, light that is emitted from the LEDs, that is reflected off the optical sheets and that is reflected off the surface of the connectors is lower than light that is emitted from the LEDs, that is reflected off the optical sheets and that is reflected off the surface of the reflective members. Hence, when seem from the side of the display panel, the brightness of portions on the connectors is lower than that of portions other than the portions on the connector. Thus, the brightness of the display panel is disadvantageously made uneven.
Hence, a backlight device that overcomes this problem is proposed (for example, see patent document 1).
Patent document 1 discloses the backlight device including: a plurality of wiring substrates on which a plurality of LEDs (point light sources) are mounted; connectors which are arranged on the wiring substrates and through which signals for lighting up the LEDs are input and output; a reflective plate (reflective member) which is arranged on the wiring substrates; and a diffusion plate that is arranged on the light emitting side of the LEDs.
Patent document 1 proposes structures such as a structure where opening portions for electrically connecting the LEDs to the wiring substrates are formed in the reflective plate and where a reflective sheet is additionally provided to cover the surface of the connectors and a structure where notches are formed in the reflective plate to provide flap portions and where the flap portions are arranged to cover the surface of the connectors.
In the backlight device of patent document 1, the reflective sheet is additionally provided to cover the surface of the connectors and the flap portions of the reflective plate are arranged to cover the surface of the connectors, and thus it is possible to reduce the occurrence of loss of light on the surface of the connectors.
Patent document 1: JP-A-2008-147147
However, when, as in the backlight device of patent document 1, the reflective sheet is additionally provided to cover the surface of the connectors, since it is necessary to adhere the reflective sheet to each of the connectors, the number of production steps is disadvantageously increased.
Moreover, when the flap portions of the reflective plate are arranged to cover the surface of the connectors, since it is necessary to bend the base portions of the flap portions, a stress is applied to the portions (base portions) where the flap portions are bent. Hence, when the backlight device is used for a long period of time, the portions where the flap portions are bent may be folded or curved due to a temperature environment or a humidity environment. In this case, since the surface of the connectors is exposed, loss of light is produced on the surface of the connectors, and thus the brightness of a display panel is disadvantageously made uneven.
The present invention is made to solve the forgoing problem; an object of the present invention is to provide a backlight device, a display device and a television receiver that can reduce the increase in the number of production steps and that can reduce the unevenness of the brightness of a display panel.
To achieve the above object, according to a first aspect of the present invention, there is provided a backlight device including: a plurality of point light sources; a substrate having one surface on which the point light sources are mounted; and a connector which is arranged on the one surface of the substrate, in which a luminous flux, in a vicinity of the connector, of light emitted from the point light sources is higher than a luminous flux, in an area other than the vicinity of the connector, of the light emitted from the point light sources.
In the backlight device of the first aspect, as described above, since the luminous flux around the connectors can be made higher than the luminous flux in the area other than the vicinity of the connectors, even if loss of light is produced on the surface of the connectors, the loss of light produced on the surface of the connectors can be compensated for by the luminous flux around the connectors. In this way, when seem from the side of the display panel, it is possible to reduce the decrease in the brightness of portions on the connectors as compared with the brightness of a portion other than the portions on the connectors, and thus it is possible to reduce unevenness of the brightness of the display panel.
In the backlight device of the first aspect, as described above, since it is unnecessary to additionally provide the reflective sheet covering the surface of the connectors so as to reduce unevenness of the brightness of the display panel, it is possible to reduce the increase in the number of production steps.
In the backlight device of the first aspect, as described above, it is unnecessary to provide flap portions in the reflective member so as to reduce unevenness of the brightness of the display panel, and to arrange the flap portions such that the flap portions cover the surface of the connectors. In this way, even when the backlight device is used for a long period of time, since it is possible to prevent the reflective member from being folded or curved, it is possible to reduce unevenness of the brightness of the display panel.
Preferably, in the backlight device of the first aspect, the point light sources include a first point light source that is arranged adjacent to the connector and a second point light source that is arranged at a position away from the connector as compared with the first point light source, and a luminous flux emitted from the first point light source is higher than a luminous flux emitted from the second point light source. In this configuration, since it is possible to easily make the luminous flux around the connectors higher than the luminous flux in the area other than the vicinity of the connectors, it is possible to easily reduce unevenness of the brightness of the display panel.
Preferably, in the backlight device where the point light sources include the first point light source and the second point light source, a current flowing through the first point light source is larger than a current flowing through the second point light source. In this configuration, since it is possible to easily make the luminous flux emitted from the first point light source higher than the luminous flux emitted from the second light source, it is possible to easily reduce unevenness of the brightness of the display panel.
Preferably, in the backlight device where the point light sources include the first point light source and the second point light source, the luminous efficiency of the first point light source is higher than the luminous efficiency of the second point light source. In this configuration, since it is possible to easily make the luminous flux emitted from the first point light source higher than the luminous flux emitted from the second light source, it is possible to easily reduce unevenness of the brightness of the display panel.
Preferably, in the backlight device of the first aspect, a density of the point light sources arranged in the vicinity of the connector is higher than a density of the point light sources arranged in the area other than the vicinity of the connector. In this configuration, since it is possible to easily make the luminous flux around the connectors higher than the luminous flux in the area other than the vicinity of the connectors, it is possible to easily reduce unevenness of the brightness of the display panel.
Preferably, in the backlight device where the density of the point light sources arranged in the vicinity of the connector is higher than the density of the point light sources arranged in the area other than the vicinity of the connector, the point light sources include the first point light source that is arranged adjacent to the connector and the second point light source that is arranged at a position away from the connector as compared with the first point light source, a plurality of the substrates are provided and a distance between the first point light sources on the adjacent substrates is less than a distance between the first point light source and the second point light source on one of the substrates. In this configuration, since it is possible to easily make the density of the point light sources arranged in the vicinity of the connector higher than the density of the point light sources arranged in the area other than the vicinity of the connector, it is possible to easily reduce unevenness of the brightness of the display panel.
Preferably, in the backlight device of the first aspect, a reflective member is provided in a predetermined region on the one surface of the substrate. In this configuration, it is possible to easily enhance the efficiency of use of light.
In the backlight device of the first aspect, the point light sources may be arranged in a longitudinal direction of the substrate.
Preferably, in the backlight device where the substrate is formed in the shape of a rectangle when seen in plan view, the point light sources are arranged on one of the substrates in the longitudinal direction of the substrate with a same pitch. In this configuration, it is possible to further reduce unevenness of the brightness of the display panel.
In the backlight device where the substrate is formed in the shape of a rectangle when seen in plan view, the connector may be arranged at an end portion of the substrate in the longitudinal direction, and a plurality of the substrates may be arranged along the longitudinal direction.
Preferably, in the backlight device of the first aspect, a plurality of the substrates are provided, and the connector electrically connects the adjacent substrates. In this configuration, it is possible to easily and electrically connect a plurality of the substrates either in series or in parallel.
Preferably, in the backlight device of the first aspect, the point light source is a light-emitting diode. In this configuration, it is possible to increase the life of the point light source and reduce the power consumption of the point light source.
Preferably, in the backlight device of the first aspect, a plurality of diffusion lenses are provided to cover a plurality of the point light sources, respectively. In this configuration, since it is possible to diffuse the light emitted from the point light sources, it is possible to further reduce unevenness of the brightness of the display panel.
A display device according to a second aspect of the present invention includes: the backlight device configured as described above; and a display panel that is illuminated by the backlight device. In this configuration, it is possible to obtain the display device that can prevent the number of production steps from being increased and that can reduce unevenness of the brightness of the display panel.
Preferably, in the display device of the second aspect, the display panel includes a liquid crystal display panel. In this configuration, it is possible to obtain the liquid crystal display device that can prevent the number of production steps from being increased and that can reduce unevenness of the brightness of the display panel.
A television receiver according to a third aspect of the present invention includes: the display device configured as described above; a cabinet that holds the display device; a tuner; and a speaker. In this configuration, it is possible to obtain the television receiver that can prevent the number of production steps from being increased and that can reduce unevenness of the brightness of the display panel.
As described above, according to the present invention, it is possible to easily obtain the backlight device, the display device and the television receiver that can prevent the number of production steps from being increased and that can reduce unevenness of the brightness of the display panel.
[
[
[
[
[
[
[
[
[
[
[
[
Embodiments of the present invention will be described below with reference to accompanying drawings.
The structure of a liquid crystal television receiver 1 incorporating a backlight device 20 according to a first embodiment of the present invention will first be described with reference to
As shown in
The front cabinet 2 and the back cabinet 3 hold the liquid crystal display device 10, the tuner 5 and the power supply 6. The tuner 5 has the function of producing the image signals and sound signals of a predetermined channel from received radio waves. The speaker 4 has the function of producing sound based on the sound signals produced by the tuner 5. The power supply 6 is configured to feed electric power to the liquid crystal display device 10, the speaker 4 and the tuner 5. The liquid crystal display device 10 is supported by the support member 7. The speaker 4, the tuner 5 and the power supply 6 may be incorporated in the liquid crystal display device 10.
As shown in
The liquid crystal display panel 12 includes an AM substrate (active matrix substrate) 12a and an opposite substrate 12b that is arranged opposite the AM substrate 12a. Liquid crystal (not shown) is sealed in between the AM substrate 12a and the opposite substrate 12b. The liquid crystal display panel 12 is illuminated by the backlight device 20 to function as a display panel.
The backlight device 20 includes: a plurality of substrates 22 on which a plurality of LEDs 21 are mounted; connectors 23 that connect the adjacent substrates 22, for example, in series; a reflective sheet 24 that is arranged on the side of the front surfaces 22a of the substrates 22; a diffusion plate 25 and a plurality of optical sheets 26 that are arranged on the side of the front surface of the reflective sheet 24; and a front chassis 27 and a back chassis 28 that hold these components. The LED 21 is an example of a “point light source” and a “light-emitting diode” of the present invention; the front surface 22a is an example of “one surface” of the present invention. The reflective sheet 24 is an example of a “reflective member” of the present invention.
The substrate 22 is formed in the shape of a rectangle when seen in plan view. For example, three of the substrates 22 are arranged along the longitudinal direction of the substrate 22, and, for example, five of the substrates 22 are arranged in the lateral direction of the substrate 22. In the following description, the longitudinal direction of the substrate 22 is referred to as A direction, and the lateral direction of the substrate 22 is referred to as B direction.
As shown in
The substrates 22 are configured such that current (power) is supplied to make the LEDs 21 emit light.
For example, three of the LEDs 21 are arranged on the front surface 22a of each of the substrates 22 along the A direction. The LEDs 21 are formed to emit light toward the front (the side of the diffusion plate 25). Each of the LEDs 21 is provided with a diffusion lens 29 having the function of diffusing light such that the diffusion lens 29 convers the LED 21. The diffusion lens 29 is formed of, for example, a transparent resin.
Here, in the first embodiment, for example, three of the LEDs 21 mounted on one of the substrates 22 are arranged with a predetermined pitch (P1). In other words, the three of the LEDs 21 are arranged on one of the substrates 22 with the same pitch in the A direction.
The LEDs 21 includes LEDs 21a that are arranged adjacent to the connectors 23 and LEDs 21b that are arranged at a position away from the connectors 23 as compared with the LEDs 21a.
In the first embodiment, a distance between the LEDs 21a on the adjacent substrates 22 is equal to a distance between the LED 21a and the LED 21b on one of the substrates 22. In other words, all the LEDs 21 mounted on three of the substrates 22 arranged in the A direction are arranged with the same pitch (P1). The LED 21a is an example of a “first point light source” of the present invention; the LED 21b is an example of a “second point light source” of the present invention.
The LED 21 is formed with, for example, a blue light-emitting element and a fluorescent member that converts part of blue light emitted from the blue light-emitting element into yellow light; the blue light and the yellow light are mixed together to provide white light.
The LED 21 may be formed with, for example, a blue light-emitting element and a fluorescent member that converts part of blue light emitted from the blue light-emitting element into red light and green light; the blue light, the red light and the green light may be mixed together to provide white light.
The LED 21 may be formed with, for example, a blue light-emitting element, a fluorescent member that is arranged on the blue light-emitting element and that converts part of blue light into green light and a red light-emitting element; the blue light, the green light and the red light may be mixed together to provide white light.
The LED 21 may be formed with, for example, an ultraviolet light-emitting element and a fluorescent member that converts ultraviolet light into blue light, green light and red light.
In the first embodiment, a luminous flux LA that is emitted from the LED 21a arranged adjacent to the connector 23 is higher than a luminous flux LB that is emitted from the LED 21b arranged at a position away from the connector 23 as compared with the LED 21a. Specifically, a relationship “LA/LB=about 1.05 to about 1.10” is preferably satisfied between the luminous flux LA emitted from the LED 21a and the luminous flux LB emitted from the LED 21b.
For example, a current flowing through the LED 21a is made larger than a current flowing through the LED 21b, and thus it is possible to easily make the luminous flux LA emitted from the LED 21a higher than the luminous flux LB emitted from the LED 21b.
As the LED 21a arranged adjacent to the connector 23, the LED 21 that has luminous efficiency higher than that of the LED 21b is used, and thus it is possible to easily make the luminous flux LA emitted from the LED 21a higher than the luminous flux LB emitted from the LED 21b. In this case, since the current that is passed through the LED 21a can be made equal to the current that is passed through the LED 21b, it is possible to prevent the circuit configuration from being complicated.
As the LED 21a, the LED 21 that has luminous efficiency higher than that of the LED 21b may be used, and the current that is passed through the LED 21a may be made larger than the current that is passed through the LED 21b.
As shown in
In the reflective sheet 24, a plurality of opening portions 24a through which the LEDs 21 and the diffusion lenses 29 are inserted and a plurality of opening portions 24b through which the connectors 23 are inserted are formed. The opening portion 24a is formed to have its inside diameter slightly larger than the outside diameter of the diffusion lens 29. The opening portion 24b is formed to have an opening slightly larger than the outside shape of a pair of connectors 23 adjacent to each other.
The diffusion plate 25 has the function of reflecting part of the light emitted from the LEDs 21 toward the side of the reflective sheet 24 and of transmitting the remainder of the light emitted from the LEDs 21 toward the side of the liquid crystal display panel 12 (the side of the optical sheets 26).
The optical sheets 26 (see
The front chassis 27 and the back chassis 28 (see
In the first embodiment, as described above, the luminous flux LA emitted from the LED 21a is made higher than the luminous flux LB emitted from the LED 21b, and thus it is possible to make a luminous flux around the connectors 23 higher than a luminous flux in an area other than the vicinity of the connectors 23. Here, since the light reflectance of the surface of the connector 23 is lower than that of the surface of the reflective sheet 24, loss of light is produced on the surface of the connectors 23. However, since, in the first embodiment, the luminous flux around the connectors 23 can be made higher than the luminous flux in the area other than the vicinity of the connectors 23, even if loss of light is produced on the surface of the connectors 23, the loss of light produced on the surface of the connectors 23 can be compensated for by the luminous flux around the connectors 23. In this way, when seem from the side of the liquid crystal display panel 12, it is possible to reduce the decrease in the brightness of portions on the connectors 23 as compared with the brightness of a portion other than the portions on the connectors 23, and thus it is possible to reduce the unevenness of the brightness of the liquid crystal display panel 12.
Since, in the first embodiment, as described above, it is unnecessary to additionally provide the reflective sheet covering the surface of the connectors 23 so as to reduce the unevenness of the brightness of the liquid crystal display panel 12, it is possible to reduce the increase in the number of production steps.
In the first embodiment, as described above, it is unnecessary to provide flap portions in the reflective sheet 24 so as to reduce the unevenness of the brightness of the liquid crystal display panel 12, and to arrange the flap portions such that the flap portions cover the surface of the connectors 23. In this way, even when the backlight device 20 is used for a long period of time, since it is possible to prevent the reflective sheet 24 from being folded or curved, it is possible to reduce the unevenness of the brightness of the liquid crystal display panel 12.
In the first embodiment, as described above, the current flowing through the LED 21a is made larger than the current flowing through the LED 21b, and thus it is possible to easily make the luminous flux LA emitted from the LED 21a higher than the luminous flux LB emitted from the LED 21b.
In the first embodiment, as described above, the luminous efficiency of the LED 21a is made higher than that of the LED 21b, and thus it is possible to easily make the luminous flux LA emitted from the LED 21a higher than the luminous flux LB emitted from the LED 21b.
In the first embodiment, as described above, the LEDs 21 are arranged on one of the substrates 22 with the same pitch in the A direction, and thus it is possible to further reduce the unevenness of the brightness of the liquid crystal display panel 12.
In the first embodiment, as described above, as the point light source, the light-emitting diode (LED 21) is used, and thus it is possible to increase the life of the point light source (LED 21) and to reduce the power consumption of the point light source (LED 21).
Since, in the first embodiment, as described above, the diffusion lenses 29 are provided to cover the LEDs 21 and thus it is possible to diffuse the light emitted from the LEDs 21, it is possible to further reduce the unevenness of the brightness of the liquid crystal display panel 12.
An experiment that has been performed to confirm the effects described above will now be described with reference to
In this confirmation experiment, Examples 1 and 2 corresponding to the first embodiment and Comparative examples 1 and 2 were used. On the Example 1 corresponding to the first embodiment and the Comparative example 1, the characteristic of the brightness of the light, in the A direction, passing through the liquid crystal display panel 12 was determined by simulation. On the Example 2 corresponding to the first embodiment and the Comparative example 2, the characteristic of the brightness of the light, within a plane, passing through the liquid crystal display panel 12 (the characteristic of the brightness in the A direction and the B direction) was determined by simulation.
A simulation that was used to determine the characteristic of the brightness of the light, in the A direction, passing through the liquid crystal display panel 12 will first be described.
In the Example 1, as shown in
In the Comparative example 1, the luminous flux LA emitted from the LED 21a that was arranged adjacent to the connector 23 and the luminous flux LB emitted from the LED 21b that was arranged at a position away from the connector 23 as compared with the LED 21a were equal to each other. The other structures in the Comparative example 1 were the same as in Example 1.
On the Example 1 and the Comparative example 1, the characteristic of the brightness of the light, in the A direction, passing through the diffusion plate 25 and the liquid crystal display panel 12 was determined by simulation. The results thereof are shown in
With reference to
A simulation that was used to determine the characteristic of the brightness of the light, within the plane, passing through the liquid crystal display panel 12 will now be described.
In the Example 2, three substrates 22 were connected along the A direction. In the Example 2, as in the Example 1, a relationship “LA/LB=1.05” was satisfied between the luminous flux LA emitted from the LED 21a and the luminous flux LB emitted from the LED 21b. The other structures in the Example 2 were the same as in Example 1.
In the Comparative example 2, the luminous flux LA emitted from the LED 21a and the luminous flux LB emitted from the LED 21b were equal to each other. The other structures in the Comparative example 2 were the same as in Example 2.
On the Example 2 and the Comparative example 2, the characteristic of the brightness of the light, within the plane, passing through the diffusion plate 25 and the liquid crystal display panel 12 was determined by simulation. The results thereof are shown in
With reference to
In a second embodiment, unlike the first embodiment, a case where the density of LEDs 121 arranged around the connectors 23 is increased will be described with reference to
In a backlight device according to the second embodiment of the present invention, as shown in
Here, in the second embodiment, for example, three of the LEDs 121 mounted on one of the substrates 122 are arranged with a predetermined pitch (P11). In other words, three of the LEDs 121 are arranged on one of the substrates 122 with the same pitch in the A direction.
In the second embodiment, a distance between the LEDs 121a, among the LEDs 121, that are arranged adjacent to the connectors 23 is less than a distance between the LED 21a and the LED 121b that is arranged at a position away from the connector 23 as compared with the LED 121a. In other words, a pitch (P12) between the LEDs 121a on the adjacent substrates 122 is less than the pitch (P11) between the LED 121a and the LED 121b. Thus, the density of the LEDs 121 arranged around the connectors 23 is higher than that of the LEDs 121 arranged in an area other than the vicinity of the connectors 23. A relationship “P12/P11=about 0.93 to about 0.98” is preferably satisfied between the pitch (P12) between the LEDs 121a and the pitch (P11) between the LED 121a and the LED 121b. The LED 121a is an example of the “first point light source” of the present invention; the LED 121b is an example of the “second point light source” of the present invention.
In the second embodiment, the luminous flux emitted from the LED 121a is equal to the luminous flux emitted from the LED 121b.
The other structures in the second embodiment are the same as in the first embodiment.
In the second embodiment, as described above, the density of the LEDs 121 arranged around the connectors 23 is made higher than that of the LEDs 121 arranged in the area other than the vicinity of the connectors 23, and thus it is possible to easily make the luminous flux around the connectors 23 higher than the luminous flux in the area other than the vicinity of the connectors 23. In this way, even if loss of light is produced on the surface of the connectors 23, since, when seem from the side of the liquid crystal display panel 12, it is possible to easily prevent the brightness of the portions on the connectors 23 from becoming lower than the brightness of the portions other than the portions on the connectors 23, it is possible to reduce the unevenness of the brightness of the liquid crystal display panel 12.
In the second embodiment, as described above, the distance between the LEDs 121a on the adjacent substrates 122 is made less than the distance between the LED 121a and the LED 121b, and thus it is possible to easily make the density of the LEDs 121 arranged around the connectors 23 higher than that of the LEDs 121 arranged in the area other than the vicinity of the connectors 23. Consequently, it is possible to easily reduce the unevenness of the brightness of the liquid crystal display panel 12.
The other effects in the second embodiment are the same as in the first embodiment.
An experiment that has been performed to confirm the effects described above will now be described with reference to
In this confirmation experiment, Examples 3 and 4 corresponding to the second embodiment were used. On the Example 3 corresponding to the second embodiment, the characteristic of the brightness of the light, in the A direction, passing through the liquid crystal display panel 12 was determined by simulation. On the Example 4 corresponding to the second embodiment, the characteristic of the brightness of the light, within a plane, passing through the liquid crystal display panel 12 (the characteristic of the brightness in the A direction and the B direction) was determined by simulation.
A simulation that was used to determine the characteristic of the brightness of the light, in the A direction, passing through the liquid crystal display panel 12 will first be described.
In the Example 3, as shown in
On the Example 3, the characteristic of the brightness of the light, in the A direction, passing through the diffusion plate 25 and the liquid crystal display panel 12 was determined by simulation. The result thereof is shown in
With reference to
A simulation that was used to determine the characteristic of the brightness of the light, within the plane, passing through the liquid crystal display panel 12 will now be described.
In the Example 4, three substrates 122 were connected along the A direction. In the Example 4, as in the Example 3, the relationship “P22/P21=0.95” was satisfied between the pitch (P22) between the LEDs 121a and the pitch (P21) between the LED 121a and the LED 121b. The luminous flux emitted from the LED 121a was equal to the luminous flux emitted from the LED 121b. The other structures in the Example 4 were the same as in Example 3.
On the Example 4, the characteristic of the brightness of the light, within the plane, passing through the diffusion plate 25 and the liquid crystal display panel 12 was determined by simulation. The result thereof is shown in
With reference to
It should be considered that the embodiments and the Examples disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is indicated not by the description of the embodiments and the Examples discussed above but by the scope of claims, and furthermore, meanings equivalent to the scope of claims and all modifications within the scope are included.
For example, although, in the embodiments described above, the example where the display panel, the display device and the television receiver are applied to the liquid crystal display panel, the liquid crystal display device and the liquid crystal television receiver, respectively, has been described, the present invention is not limited to this example. The display panel, the display device and the television receiver may be applied to a display panel, a display device and a television receiver other than the liquid crystal display panel, the liquid crystal display device and the liquid crystal television receiver.
Although, in the embodiments described above, the example where the LED is used as the point light source has been described, the present invention is not limited to this example. For example, a point light source other than the LED, such as a semiconductor laser element, may be used.
Although, in the embodiments and the Examples described above, the example where two or three of the LEDs are mounted on each of the substrates has been described, the present invention is not limited to this example. Four or more of the LEDs may be mounted on one of the substrates.
Although, in the embodiments described above, the example where the LED is configured to emit white light has been described, the present invention is not limited to this example. The LED may be configured to emit light other than white light.
Although, in the embodiments described above, the example where the LED is formed with a light-emitting element and a fluorescent member has been described, the present invention is not limited to this example. For example, instead of using a fluorescent member, the LED may be formed with a blue light-emitting element, a red light-emitting element and a green light-emitting element.
Although, in the embodiments described above, the example where the LEDs are mounted in a row has been described, the present invention is not limited to this example. The LEDs may be mounted in a plurality of rows on each of the substrates.
Although, in the embodiments described above, the example where the diffusion lens is provided to cover the LED has been described, the present invention is not limited to this example. The diffusion lens covering the LED does not need to be provided.
Although, in the embodiments described above, the example where the connector is provided at the end portion of the substrate has been described, the present invention is not limited to this example. The present invention can be applied to a case where the connector is provided at a position other than the end portion of the substrate.
Although, in the embodiments described above, the example where a plurality of substrates are provided has been described, the present invention is not limited to this example. The present invention can be applied to a case where only one substrate is provided.
Although, in the embodiments described above, the example where the connector electrically connecting the adjacent substrates is used has been described, the present invention is not limited to this example. A connector which connects the substrate and a member other than the substrate may be used.
Although, in the first embodiment, the example where the luminous flux emitted from the LED 21a is made higher than the luminous flux emitted from the LED 21b has been described, and in second embodiment, the example where the density of the LEDs arranged around the connectors is made higher than that of the LEDs arranged in the area other than the vicinity of the connectors has been described, the present invention is not limited to these examples. The luminous flux emitted from the LED 21a may be made higher than the luminous flux emitted from the LED 21b, and the density of the LEDs arranged around the connectors may be made higher than that of the LEDs arranged in the area other than the vicinity of the connectors.
Although, in the first embodiment, the example where the relationship “LA/LB=about 1.05 to about 1.10” is satisfied between the luminous flux LA emitted from the LED 21a and the luminous flux LB emitted from the LED 21b has been described, the present invention is not limited to this example. As long as the luminous flux LA is higher than the luminous flux LB, the relationship “LA/LB=about 1.05 to about 1.10” may not be satisfied between the luminous flux LA and the luminous flux LB.
Although, in the second embodiment, the example where the relationship “P12/P11=about 0.93 to about 0.98” is satisfied between the pitch (P12) between the LEDs 121a and the pitch (P11) between the LED 121a and the LED 121b has been described, the present invention is not limited to this example. As long as the pitch (P12) between the LEDs 121a is less than the pitch (P11) between the LED 121a and the LED 121b, the relationship “P12/P11=about 0.93 to about 0.98” may not be satisfied between the pitch (P12) and the pitch (P11).
Although, in the second embodiment, the example where the distance between the LEDs 121a on the adjacent substrates 122 is made less than the distance between the LED 121a and the LED 121b, and thus the density of the LEDs 121 arranged around the connectors 23 is made higher than that of the LEDs 121 arranged in the area other than the vicinity of the connectors 23 has been described, the present invention is not limited to this example. By arranging at least the LEDs 121a in a plurality of rows such that the number of LEDs 121a in the B direction is larger than the number of LEDs 121b in the B direction, the density of the LEDs 121 arranged around the connectors 23 may be made higher than that of the LEDs 121 arranged in the area other than the vicinity of the connectors 23.
1 Liquid crystal television receiver (television receiver)
2 Front cabinet (cabinet)
3 Back cabinet (cabinet)
4 Speaker
5 Tuner
10 Liquid crystal display device (display device)
12 Liquid crystal display panel (display panel)
20 Backlight device
21 and 121 LED (point light source, light-emitting diode)
21
a and 121a LED (first point light source)
21
b and 121b LED (second point light source)
22 and 122 Substrate
22
a and 122a Front surface (one surface)
23 Connector
24 Reflective sheet (reflective member)
29 Diffusion lens
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-179823 | Jul 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/057220 | 4/23/2010 | WO | 00 | 1/19/2012 |
