WO2007138724A1 - バックライト装置、及びこれを用いた表示装置 - Google Patents
バックライト装置、及びこれを用いた表示装置 Download PDFInfo
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- WO2007138724A1 WO2007138724A1 PCT/JP2006/323564 JP2006323564W WO2007138724A1 WO 2007138724 A1 WO2007138724 A1 WO 2007138724A1 JP 2006323564 W JP2006323564 W JP 2006323564W WO 2007138724 A1 WO2007138724 A1 WO 2007138724A1
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- light
- light emitting
- emitting diodes
- backlight device
- installation
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
- G02B6/0068—Arrangements of plural sources, e.g. multi-colour light sources
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133603—Direct backlight with LEDs
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
- G02B6/0073—Light emitting diode [LED]
Definitions
- the present invention relates to a backlight device, particularly a backlight device having a light emitting diode as a light source, and a display device using the same.
- liquid crystal display devices have been widely used in liquid crystal televisions, monitors, mobile phones and the like as flat panel displays having features such as thinness and light weight compared to conventional cathode ray tubes.
- Such a liquid crystal display device includes a backlight device that emits light, and a liquid crystal panel that displays a desired image by acting as a shutter for light from a light source provided in the knock light device.
- an edge light type or a direct type is provided in which a linear light source composed of a cold cathode tube or a hot cathode tube is disposed on the side or below the liquid crystal panel.
- a linear light source composed of a cold cathode tube or a hot cathode tube is disposed on the side or below the liquid crystal panel.
- the above-mentioned cold cathode fluorescent lamps contain mercury and it is difficult to recycle the discarded cold cathode fluorescent lamps. Therefore, a backlight device using a light emitting diode (LED) that does not use mercury as a light source has been proposed (see, for example, Japanese Patent Application Laid-Open No. 2004-21147).
- the conventional backlight device described above is provided with three-color light emitting diodes that emit red (R), green (G), and blue (B) light, and these three colors are mixed. To obtain white light.
- a sensor that detects light from the light emitting diodes is installed, and the light intensity and color of the corresponding light emitting diodes are adjusted by adjusting the light quantity of each RGB light emitting diode based on the detection results. It was possible to suppress the change of the degree over time.
- the light emitting diodes as described above have a very large variation in the amount of light. That is, for light-emitting diodes, the model number, type, intensity, and rated current Even with products that have the same design values for various characteristics such as values and directivity angles, the amount of light from product to product may vary significantly depending on the quality and characteristics of the semiconductor material. In light-emitting diodes, the amount of light whose light-emitting efficiency is likely to change compared to cold cathode fluorescent lamps is also relatively easy to change due to changes in the usage environment, especially changes in ambient temperature.
- the light emission efficiency varies due to variations in the amount of light for each light emitting diode and changes in the surrounding environment.
- the light quantity of each of the plurality of light emitting diodes became non-uniform, and luminance unevenness was likely to occur in the light to the liquid crystal panel (external).
- the number of light-emitting diodes is increased in accordance with the increase in screen size and brightness of liquid crystal display devices, the amount of light is reduced due to the increase in the number of light-emitting diodes and the associated increase in heat generation.
- the uniform width (light intensity difference between the brightest light emitting diode and the darkest light emitting diode) could be significantly larger.
- the conventional backlight device when the number of light emitting diodes is increased, it is extremely difficult to prevent uneven brightness from occurring in the light to the outside.
- the present invention provides a backlight device capable of preventing the occurrence of uneven brightness even when the number of light emitting diodes is increased, and a display device using the backlight device. Objective.
- a backlight device includes a plurality of light emitting diodes
- the plurality of light-emitting diodes are installed in a distributed manner so that the amount of light is within a predetermined range.
- the installation areas of the light emitting diodes are mutually different. It is set in several different places. In the plurality of installation areas, the light emitting diodes are installed so that the light amounts are within a predetermined range. As a result, unlike the conventional example described above, even when the number of light emitting diodes is increased, the light emitted to the outside from the backlight device has uneven brightness due to variations in the amount of light for each light emitting diode and changes in the surrounding environment. It can be prevented from occurring.
- the backlight device includes a drive circuit that drives the light-emitting diode to light
- the plurality of installation areas are preferably set at different locations using temperature distributions when the light emitting diodes are lighted and driven by the drive circuit.
- the light emitting diode in each installation area, is appropriately installed in a state where the temperature distribution is grasped, so that the amount of light in each installation area can be easily within a predetermined range. .
- the temperature distribution in each installation area is different, it is possible to reliably prevent luminance unevenness from occurring in the light to the outside.
- the plurality of installation areas may be set at different locations using the temperature distribution including a temperature increase due to heat generated in the external device. .
- the amount of light in each installation area can be more easily within a predetermined range in a state where the adverse effects of ambient temperature fluctuations caused by heat generated from the external device are reliably eliminated. It is possible to prevent the occurrence of uneven brightness in the light to the part more reliably.
- the plurality of installation areas are set at locations where the positions in the vertical direction where gravity acts are different from each other in a use state.
- the plurality of installation areas are set at positions different from each other in the vertical direction according to the actual use state, and to the outside due to natural convection of heat generated when used. It is possible to reliably prevent the occurrence of uneven brightness of light.
- the light amounts may be within a predetermined range by changing the number of light emitting diodes to be installed. [0018] In this case, even when the supply current value to each light emitting diode is the same, it is possible to easily adjust each light quantity in a plurality of installation areas, and reliably prevent the occurrence of uneven brightness. And can be done easily.
- the light amounts may be within a predetermined range by changing the sizes of the light emitting surfaces of the installed light emitting diodes.
- the light amounts may be within a predetermined range by changing supply current values to the light-emitting diodes to be installed.
- the plurality of light emitting diodes may include a plurality of types of light emitting diodes having different emission colors.
- the backlight device can improve the color purity of the corresponding emission color compared to the case of using a white light emitting diode that emits white light, and has excellent light emission quality such as chromaticity distribution. Can be configured easily.
- the plurality of light emitting diodes include red, green
- red, green, and blue light emitting diodes that emit blue and blue light, respectively, are included.
- the color purity of each of the red, green, and blue emission colors can be improved, and a backlight device having a superior light emission quality can be easily configured.
- the backlight device in the plurality of installation regions, at least one of the number of green light emitting diodes emitting green light, the size of the light emitting surface, and the magnitude of the supply current value is used. It is preferable that the amounts of green light are mutually within a predetermined range by changing the values of each other.
- the light amount of the green light in addition to the red light emitting diode, a green light emitting diode in which the light emission efficiency and the light amount are relatively easily changed according to the change in the ambient temperature, the light amount of the green light.
- the light emission quality (chromaticity distribution) of the backlight device can be improved more easily.
- chromaticity is within a predetermined range in the plurality of installation regions.
- the backlight device may include a light guide plate into which light from the plurality of light emitting diodes is introduced.
- a light emitting surface may be arranged on a straight line with respect to an irradiation object.
- the display device of the present invention is a display device including a display unit,
- the display unit is irradiated with light from any one of the above backlight devices. It is a sign.
- the display unit is irradiated with light from the backlight device that can prevent the occurrence of uneven brightness. Therefore, even when the display portion is increased in brightness and screen size, a display device with excellent display performance can be easily configured.
- the present invention it is possible to provide a backlight device that can prevent the occurrence of luminance unevenness even when the number of light-emitting diodes is increased, and a display device using the backlight device.
- FIG. 1 is a schematic diagram illustrating a backlight device and a liquid crystal display device according to a first embodiment of the present invention.
- FIG. 2 is a plan view showing a configuration of main parts of the backlight device shown in FIG.
- FIG. 3 is a graph showing a specific example of temperature characteristics of the light emitting diode shown in FIG.
- FIG. 4 is a plan view showing the main configuration of a backlight device according to a second embodiment of the present invention.
- FIG. 5 is a schematic diagram for explaining a backlight device and a liquid crystal display device according to a third embodiment of the present invention.
- FIG. 6 is a plan view showing an arrangement example of light emitting diodes in the backlight device shown in FIG. 5.
- FIG. 6 is a plan view showing an arrangement example of light emitting diodes in the backlight device shown in FIG. 5.
- FIG. 7 is a plan view showing an arrangement example of light emitting diodes in a backlight device according to a fourth embodiment of the present invention.
- FIG. 8 is a plan view showing an arrangement example of light emitting diodes in a backlight device according to a fifth embodiment of the present invention.
- FIG. 1 is a schematic diagram for explaining a backlight device and a liquid crystal display device according to a first embodiment of the present invention
- FIG. 2 is a plan view showing a main configuration of the backlight device shown in FIG. 1 and 2, in the present embodiment, the backlight device 2 of the present invention and a liquid crystal panel 3 as a display unit irradiated with light from the backlight device 2 are provided.
- These backlight devices 2 and the liquid crystal panel 3 are integrated as a transmissive liquid crystal display device 1.
- the knock light device 2 includes a plurality of light emitting diodes 4 as light sources, and a light guide plate 5 into which light from each of the plurality of light emitting diodes 4 is introduced.
- the 3 side is irradiated with flat illumination light.
- the plurality of light emitting diodes 4 are either one of an upper region and a lower region respectively set on the upper side and the lower side of FIG.
- One light emitting diode 4 is provided in the installation area.
- the upper region and the lower region are arranged inside the liquid crystal display device 1 so as to face the upper portion and the lower portion in the horizontal direction of the display surface (not shown) provided in the liquid crystal panel 3, respectively. Embedded in.
- the upper region and the lower region are respectively arranged on the upper side and the lower side in the vertical direction in which gravity acts when the liquid crystal display device 1 is used.
- the temperature distribution over time is different from each other (details will be described later).
- the plurality of light emitting diodes 4 include red, green, and blue light emitting diodes 4r, 4g, and 4g that emit red (R), green (G), and blue (B) light, respectively. 4b is included. These red, green, and blue light-emitting diodes 4r, 4g, and 4b are shown in FIG. 2 in the form of no, non-chatting, hatching, and cross-hatching, respectively (see FIGS. 4, 6). The same applies to Fig. 7 and Fig.
- the amount of light emitted toward the light guide plate 5 varies between the upper region and the lower region.
- the number of installations in the upper area and the number of installations in the lower area are set to be different so that they are within a predetermined range.
- the number of light emitting diodes 4r, 4g, and 4b is appropriately reduced to simplify the drawing (the same applies to FIGS. 4 and 6 to 8 described later). .
- the specific number of the light emitting diodes 4r, 4g, and 4b is several tens of units.
- liquid crystal display device 1 for example, a polarizing sheet 6, a prism (light collecting) sheet 7, and a diffusion sheet 8 are installed between the liquid crystal panel 3 and the light guide plate 5. These optical sheets Accordingly, the brightness of the illumination light from the non-light device 2 is appropriately increased, and the display performance of the liquid crystal panel 3 is improved.
- a liquid crystal layer (not shown) force included in the liquid crystal panel 3 is connected to the drive control circuit 10 with an FPC (F1 exible printed circuit) 9 interposed therebetween, and the drive The control circuit 10 is configured to be able to drive the liquid crystal layer in units of pixels.
- the drive control circuit 10 includes a calculation unit such as a CPU, and is included in an external device of the backlight device 2 that functions as a heat source. Further, as shown in FIG. 1, the drive control circuit 10 is attached on the back side of the light guide plate 5 of the knocklight device 2, for example, in the vicinity of the upper region. That is, the drive control circuit 10 is installed on the non-display surface side of the liquid crystal panel 3 of the light guide plate 5 and on the upper side in the vertical direction along the horizontal direction of the display surface.
- a lighting drive circuit 11 as a drive circuit that drives and drives the plurality of light emitting diodes 4 is provided at, for example, an intermediate position between the upper side and the lower side in the vertical direction. It is installed on the back side.
- the lighting drive circuit 11 includes a power supply circuit that constitutes a power source for each light emitting diode 4 and a control (IC) chip that controls lighting driving for each light emitting diode 4. Constructs a heat source on the light device 2 side.
- the light guide plate 5 for example, a synthetic resin such as a transparent acrylic resin is used.
- the light guide plate 5 has a rectangular cross section. In the light guide plate 5, light from the light emitting diodes 4 in the upper region and the lower region is incident on the upper side surface and the lower side surface, respectively. Thereafter, in the light guide plate 5, the illumination light is emitted toward the liquid crystal panel 3 from the light emitting surface arranged to face the diffusion sheet 8.
- the light emitting diodes 4 and the light guide plate 5 in the upper region and the lower region are accommodated in a housing (not shown), and the light from each light emitting diode 4 leaks to the outside. Directly against the inside of the light guide plate 5 from the corresponding upper side surface or lower side surface while being prevented as much as possible. It is efficiently introduced indirectly or indirectly through a reflector. Thereby, in the knocklight device 2, the light use efficiency of each light-emitting diode 4 can be easily improved, and the brightness of the illumination light can be easily increased.
- the upper region and the lower region which are the regions where the light emitting diodes 4 are installed, are set at different locations using the temperature distribution when the liquid crystal display device 1 is used. ing. More specifically, in the backlight device 2, the temperature distribution inside the casing when the liquid crystal display device 1 is used is obtained in advance by actual measurement or simulation, and the vertical direction when the liquid crystal display device 1 is used. It is known in advance that the upper region disposed on the upper side of the region is a region having a higher temperature, for example, about 10 to 15 ° C than the lower region disposed on the lower side in the vertical direction.
- the temperature of the upper region is not only the heat from the light emitting diode 4 installed therein, but also the light emitting diode 4, the drive control circuit 10, and the lighting of the lower region. Due to the influence of each heat from the drive circuit 1 1 (natural convection of heat), it is determined in advance that the temperature rise is about 10 to 15 ° C compared to the temperature in the lower region. Are set as different upper and lower regions.
- the plurality of light emitting diodes 4 include light emitting diodes 4r, 4g, and 4b that emit light of each color of RGB.
- the introduced RGB light emitting diodes 4r, 4g, and 4b are included.
- Each color light is mixed with white light, and the white light is emitted from the light emitting surface as illumination light.
- the backlight device 2 can improve the light emission quality of the illumination light, make it possible to make the illumination light suitable for a full-color image incident on the liquid crystal panel 3, and easily improve the display quality of the liquid crystal panel 3. .
- each of the RGB light emitting diodes 4r, 4g, 4b depends on the size of the liquid crystal panel 3 and the display performance such as luminance and display quality required for the liquid crystal panel 3.
- the number of installations, types, sizes, etc. are selected.
- a power LED with a power consumption of about S1W or a chip LED with a power consumption of about 70mW is used as appropriate.
- the light amounts emitted from the upper region and the lower region toward the light guide plate 5 are mutually determined using the temperature distributions in the upper region and the lower region.
- the number of light emitting diodes 4r, 4g, and 4b is determined in each of the upper region and the lower region so as to be within a predetermined range.
- the illumination light has uneven luminance within a predetermined range with the relative light amount difference between the upper region and the lower region having different temperature distributions within a predetermined range. It is designed to prevent as much as possible.
- the light emitting diodes 4r, 4g, and 4b of each color are installed in an appropriately dispersed manner. Further, based on the temperature distribution in the upper region and the lower region when the liquid crystal display device 1 is used in advance, the light amount difference due to the difference in ambient temperature between the upper region and the lower region is calculated. The number of light emitting diodes 4r, 4g, 4b installed in the upper region and the lower region is determined so as not to occur as much as possible.
- the light-emitting diode 4 changes its luminous efficiency and the amount of light according to the ambient temperature. Further, in the light emitting diode 4, the ratio of each change in the light emission efficiency and the light amount with respect to the ambient temperature differs depending on the difference in the light emission color, that is, the type of the light emission color. That is, as illustrated in FIG. 3, when the light intensity at room temperature (25 ° C) is 1, the red light emitting diode emits light as the ambient temperature increases as shown by the curve 50r. The efficiency decreases and the relative light intensity (light intensity) also decreases.
- the number of red light emitting diodes 4 r installed is higher than the lower region, which is lower in temperature when the liquid crystal display device 1 is used.
- the areas are arranged so as to be larger, and the amount of red light during use is within a predetermined range in the upper area and the lower area.
- the number of installation in the upper region and the lower region is determined according to the temperature characteristics shown in FIG. Light intensity of green light and blue light Is within a predetermined range in the upper region and the lower region.
- an upper region and a lower region having different temperature distributions when the liquid crystal display device 1 is used are set as the installation region of the light emitting diode 4.
- the light emitting diodes 4 are installed so that the light amounts are within a predetermined range.
- the illumination light emitted from the non-crite device 2 to the outside is not uniform in the amount of light for each light emitting diode. It is possible to prevent luminance unevenness caused by changes in the surrounding environment.
- the liquid crystal panel (display unit) 3 Even when the brightness is increased and the screen size is increased, the liquid crystal display device 1 having excellent display performance can be easily configured.
- FIG. 4 is a plan view showing a main configuration of a backlight device according to the second embodiment of the present invention.
- the main difference between the present embodiment and the first embodiment is that a plurality of light emitting diodes are arranged facing the left side surface and the right side surface of the light guide plate 5. Note that elements that are the same as those in the first embodiment are given the same reference numerals, and redundant descriptions thereof are omitted.
- the plurality of light emitting diodes 4 are arranged to face the left side surface and the right side surface of the light guide plate 5, and light is emitted from these left side surface and right side surface. Is introduced into the light guide plate 5. Further, in the light guide plate 5, when the liquid crystal display device 1 is used, the light guide plate 5 is incorporated in the nocrite device 2 so that the upper portion in FIG. 4 is on the upper side in the vertical direction.
- the installation area of the light-emitting diode 4 is set to be divided into an upper area and a lower area with the middle part of 4 in the vertical direction as a boundary. That is, the upper region and the lower region are determined using the temperature rise value when the liquid crystal display device 1 is used, including the temperature rise amount of the drive control circuit 10, as in the first embodiment. Are set in different places.
- the upper region and the upper region and the lower region are arranged so that the amounts of light emitted from the upper region and the lower region toward the light guide plate 5 are within a predetermined range.
- the number of light emitting diodes 4r, 4g, 4b is determined in each of the lower regions. For example, as shown in FIG. 4, the number of the red light emitting diodes 4r is arranged so that the upper region having a high temperature is larger than the lower region having a low temperature when the liquid crystal display device 1 is used. Therefore, the amount of red light during use is set within a predetermined range in the upper area and the lower area.
- the relative light quantity in the upper and lower regions with different temperature distributions is reduced. Since the difference is within the predetermined range, the same effect as the first embodiment can be obtained.
- FIG. 5 is a schematic diagram for explaining a backlight device and a liquid crystal display device according to a third embodiment of the present invention
- FIG. 6 is a plan view showing an arrangement example of light emitting diodes in the backlight device shown in FIG. It is.
- the main difference between this embodiment and the second embodiment is that a direct-type backlight device in which a plurality of light-emitting diodes are arranged on the lower side of the liquid crystal panel is configured. Note that elements that are the same as in the second embodiment are given the same reference numerals, and redundant descriptions thereof are omitted.
- the plurality of light emitting diodes 4 are housed in a bottomed case 12 having an upper end opened.
- a diffusion plate 13 is installed on the opening side of the case 12 so as to close the opening instead of the diffusion sheet 8.
- the light emitting surface of each light emitting diode 4 is applied to the liquid crystal panel (irradiated object) 3 without the light guide plate 5 interposed therebetween.
- a direct-type backlight device arranged on a straight line is configured.
- the plurality of light emitting diodes 4 are arranged in four rows in the vertical direction of FIG. 6, and each row is set as an installation region of the light emitting diodes 4. Yes.
- the first, first, 2, 3rd and 4th installation areas are set.
- these first to fourth installation areas are set based on the internal temperature distribution of the case 12 when the liquid crystal display device 1 is used. Yes, the temperature rise in the first installation area in the bottom row is the coldest area, and the temperature rise is the hot area in the order of the second, third, and fourth installation areas.
- the first to fourth installation region forces are adjusted so that the light amounts emitted toward the liquid crystal panel 3 are within a predetermined range.
- the number of each of the light emitting diodes 4r, 4g, 4b is determined in each of the fourth installation areas. For example, as shown in FIG. 6, when the liquid crystal display device 1 is used, the number of red light-emitting diodes 4r is higher than the lower area where the temperature is lower than the lower area where the temperature is higher. The amount of red light in use is within a predetermined range in the first to fourth installation areas.
- the relative light amount difference in the first to fourth installation regions having different temperature distributions is determined in advance. Therefore, the same effect as the above embodiment can be obtained.
- FIG. 7 is a plan view showing an arrangement example of light emitting diodes in the backlight device according to the fourth embodiment of the present invention.
- the main difference between this embodiment and the third embodiment is that the total number of light emitting diodes installed in each of the plurality of installation areas is changed according to the internal temperature distribution of the case. .
- elements common to the third embodiment are given the same reference numerals, and redundant description thereof is omitted.
- the plurality of light emitting diodes 4 are the total number of light emitting diodes 4 installed in the first installation region in the bottom row (that is, light emitting diodes 4r, 4g, 4b The total number of each installed) is set to the smallest number. As the temperature rise during use of the liquid crystal display device 1 increases, the total number of light-emitting diodes 4 installed increases. That is, the total number of the light emitting diodes 4 installed in the second, third, and fourth installation areas is sequentially increased in this order.
- the light amounts emitted from the first to fourth installation areas toward the liquid crystal panel 3 are within a predetermined range.
- the number of light emitting diodes 4r, 4g, and 4b is determined.
- the number of red light-emitting diodes 4r installed is the number of liquid crystal display devices. It is arranged so that the upper area, which is hot, is larger than the lower area, which is cold when using device 1, and the amount of red light during use is the first to fourth installation.
- the areas are within a predetermined range of each other.
- the relative light amounts in the first to fourth installation regions having different temperature distributions are used. Since the difference is within a predetermined range, the same effect as the third embodiment can be obtained.
- this embodiment since the total number of the light emitting diodes 4 installed in each of the first to fourth installation areas is increased or decreased according to the internal temperature distribution of the case 12, this embodiment is more liquid crystal than the third embodiment.
- the internal temperature distribution of the case 12 is wide, and it is easier to cope with a large temperature difference between the first installation region and the fourth installation region. Can be prevented.
- FIG. 8 is a plan view showing an arrangement example of the light emitting diodes in the backlight device according to the fifth embodiment of the present invention.
- the main difference between this embodiment and the third embodiment is that the size of the light emitting surface of the light emitting diode is changed instead of changing the number of light emitting diodes in a plurality of installation areas. Thus, the amounts of light in these installation areas are within a predetermined range.
- elements common to the third embodiment are given the same reference numerals, and redundant description thereof is omitted.
- the plurality of light emitting diodes 4 are arranged in five rows in the vertical direction of FIG. 8, and each row is an installation area of the light emitting diodes 4. Is set to. That is, in the present embodiment, for example, the first and second directions along the direction from the lower side to the upper side of the vertical direction indicated by the arrow Y in FIG. 8 (that is, the direction opposite to the direction of action of gravity). Third, fourth, and fifth installation areas are set. In addition, these first to fifth installation areas are set based on the internal temperature distribution of the case 12 when the liquid crystal display device 1 is used, and the temperature rise in the first installation area in the bottom row is increased. This is the coldest area, and the temperature rise is the hot area in the order of the second, third, fourth, and fifth installation areas.
- light is emitted from the first to fifth installation areas toward the liquid crystal panel 3.
- the sizes of the light emitting surfaces of the light emitting diodes 4g and 4b are determined in each of the first to fifth installation regions so that the light amounts to be emitted are within a predetermined range.
- a red light emitting diode 4r having a light emitting surface with a different size is used. That is, in this light emitting diode 4r, the number of red light emitting elements (red chips) is different.
- one package includes a plurality of red chips, such as a so-called three-in-one (3inl) or four-in-one (4inl).
- Different LED chip sizes are used. As shown in FIG. 8, when the liquid crystal display device 1 is used, the upper region where the temperature is higher than the lower region where the temperature is lower is installed with a larger light emitting surface. The amount of red light at is set within a predetermined range in the first to fifth installation areas.
- the relative light amount difference in the first to fifth installation regions having different temperature distributions is determined in advance. Therefore, the same effect as the above embodiment can be obtained.
- the backlight device of the present invention is not limited to this, and uses light from a light source.
- the present invention can be applied to various display devices including a non-light emitting display unit that displays information such as images and characters.
- the backlight device of the present invention can be suitably used for a transflective or reflective liquid crystal display device or a projection display device such as a rear projection.
- the present invention also provides a light box for irradiating light to X-ray photographs or photographic negatives for irradiating light to facilitate visual recognition, signboards, and walls in station buildings. It can be suitably used as a backlight device for a light-emitting device that illuminates advertisements and the like that are installed.
- the present invention is applied to a liquid crystal display device installed so that the display surface is parallel to the vertical direction.
- the present invention can also be applied to a liquid crystal display device having a display surface tilted at a constant angle.
- the present invention provides a plurality of installation areas at different locations. There is no limitation as long as a plurality of light emitting diodes are installed in a distributed manner so that the areas are set and the light amounts in these installation areas are within a predetermined range.
- a plurality of installation regions are provided at different locations using a temperature distribution including a temperature rise due to heat generated in the drive control circuit (external device) of the liquid crystal panel.
- the setting is more preferable.
- the amount of light in each installation area can be more easily set within the predetermined range with the negative influence of ambient temperature fluctuations caused by heat generated from the external device being reliably eliminated. This is because the occurrence of uneven brightness of the illumination light can be prevented more reliably.
- the plurality of installation areas include not only a heat source (internal factor) such as a light emitting diode inherent in the backlight device itself, but also a heat source (disturbance) on the liquid crystal panel side where the backlight device is incorporated.
- the temperature distribution including the temperature rise caused by the temperature distribution is set at different locations, which is preferable in that the adverse effects of disturbance can be more reliably eliminated when adjusting the light intensity in each installation area. .
- the external device of the present invention is not limited to this and is an external device. Includes various electric parts, electric circuits, etc. that are attached to a backlight device as appropriate and generate heat when used to constitute a heat source. Specifically, the temperature rise due to the heat generated by the driver IC mounted on one pair of substrates included in the liquid crystal panel. A plurality of installation areas can be set in consideration of ascending.
- the relative light quantity difference is set within a predetermined range by changing the number of installed light emitting diodes or the size of the light emitting surface.
- the present invention is not limited to this, and in a plurality of installation regions, the light quantity within a predetermined range can be obtained by changing the supply current values to the installed light emitting diodes. But you can. Further, a configuration in which at least one of the number in each of the plurality of installation regions, the size of the light emitting surface, and the size of the supply current value may be changed.
- each light quantity can be easily adjusted in the installation area, and the occurrence of the luminance unevenness can be surely and easily performed.
- the light emitting surfaces of the light emitting diodes are changed in size, the light amounts in the plurality of installation areas are within a predetermined range, It is preferable in that the amount of light can be easily adjusted while simplifying the work of assembling the light emitting diodes in each of the plurality of installation areas, and the occurrence of the luminance unevenness can be surely and easily performed. .
- the present invention is not limited to this.
- a backlight device that contains only white light emitting diodes as light sources, a plurality of white light emitting diodes are dispersedly installed in a plurality of installation areas, and the amount of light from these installation areas falls within a predetermined range. You may arrange.
- the present invention can also be applied to a backlight device using light emitting diodes having different emission colors and capable of mixing with white light and having at least two colors such as yellow and blue light emitting diodes.
- red, green, and blue light emitting diodes are used as in the above embodiment, Therefore, it is possible to improve the color purity of each of the red, green, and blue emission colors included in the illumination light, so that the emission quality of the non-crite device can be easily improved and the display quality (display This is preferable in that a display device with improved performance can be easily configured.
- the case where the number of light emitting diodes of red, green, and blue is changed in the plurality of installation regions or the size of the light emitting surface has been described.
- the light-emitting diodes of any one of red, green, and blue that are not limited change at least one of the number of each installation area, the size of the light-emitting surface, and the size of the supply current value.
- the structure to do may be sufficient.
- the red light amount of the red light emitting diodes whose light emission efficiency and light amount are most likely to change according to the change in ambient temperature are set within a predetermined range. Therefore, it is possible to reliably and easily prevent the occurrence of the luminance unevenness. Furthermore, the light emission quality (chromaticity distribution) of the backlight device can be improved more easily.
- the red light emitting diode it is possible to change at least one of the number of the plurality of installation regions, the size of the light emitting surface, and the magnitude of the supply current value for the green light emitting diode. preferable. That is, in this case, in a plurality of installation areas, the green light amount of the green light-emitting diodes whose light emission efficiency and light amount are relatively easily changed according to changes in ambient temperature are within a predetermined range. Therefore, the occurrence of the luminance unevenness can be prevented more reliably, and the light emission quality (chromaticity distribution) of the backlight device can be improved more easily.
- each of the plurality of light emitting diodes is lit in advance under the same measurement conditions, thereby measuring the light amount (light flux amount and luminous intensity) of the corresponding light emitting diode, and measuring the measurement. It is also possible to use light emitting diodes that are assigned to any one of several ranks based on the results. As described above, by using the light emitting diodes that are ranked in advance with respect to the individual light amounts of the light emitting diodes, it is possible to simplify the adjustment work of aligning the light amounts in a plurality of installation areas.
- a plurality of light emitting diodes may be installed in a distributed manner so that chromaticities are within a predetermined range in a plurality of installation regions.
- the light emission quality (chromaticity distribution) of the backlight device can be improved more reliably.
- the emission spectrum of the light-emitting diodes may be measured in advance, and the color purity of the light-emitting diodes may be allocated in advance to any one of a plurality of ranks based on the measurement results and arranged in different installation areas. . In this way, when the emission spectrum is ranked in addition to the light intensity rank and placed in different installation areas, a backlight device with excellent light emission quality and a display device with excellent display quality can be more easily obtained. It is preferable in that it can be configured.
- a temperature sensor is provided in each installation area, and the supply current value to the light emitting diode in the corresponding installation area is finely adjusted based on the temperature detection result.
- the backlight device and the display device using the same according to the present invention can prevent the occurrence of uneven brightness even when the number of light emitting diodes is increased, and thus the display unit having a large screen
- the present invention is effective for a backlight device capable of emitting high-luminance light and a display device including the display unit.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2006800537250A CN101400940B (zh) | 2006-05-30 | 2006-11-27 | 背光源装置和使用该背光源装置的显示装置 |
US12/294,274 US20090251922A1 (en) | 2006-05-30 | 2006-11-27 | Backlight device and display device using the same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2006-150250 | 2006-05-30 | ||
JP2006150250 | 2006-05-30 |
Publications (1)
Publication Number | Publication Date |
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WO2007138724A1 true WO2007138724A1 (ja) | 2007-12-06 |
Family
ID=38778252
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2006/323564 WO2007138724A1 (ja) | 2006-05-30 | 2006-11-27 | バックライト装置、及びこれを用いた表示装置 |
Country Status (3)
Country | Link |
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US (1) | US20090251922A1 (ja) |
CN (1) | CN101400940B (ja) |
WO (1) | WO2007138724A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010032731A (ja) * | 2008-07-28 | 2010-02-12 | Panasonic Corp | バックライト装置 |
JP2010032730A (ja) * | 2008-07-28 | 2010-02-12 | Panasonic Corp | バックライト装置 |
CN101806414A (zh) * | 2009-02-17 | 2010-08-18 | Lg伊诺特有限公司 | 光源和具有该光源的显示设备 |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TWI348059B (en) * | 2007-08-01 | 2011-09-01 | Au Optronics Corp | Backlight module |
KR101354318B1 (ko) * | 2008-10-07 | 2014-02-05 | 엘지디스플레이 주식회사 | 백라이트 유닛 및 이를 구비한 액정표시장치 |
US20130038798A1 (en) * | 2009-12-16 | 2013-02-14 | Sharp Kabushiki Kaisha | Display device and television receiver |
US20120307523A1 (en) * | 2010-02-25 | 2012-12-06 | Sharp Kabushiki Kaisha | Light source device and display device |
US20130256705A1 (en) * | 2012-03-30 | 2013-10-03 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Light emitting diode light bar structure |
US20130272027A1 (en) * | 2012-04-11 | 2013-10-17 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Method for Manufacturing LED Light Bar and LED Light Bar and Backlight Module |
JP2019145445A (ja) * | 2018-02-23 | 2019-08-29 | シャープ株式会社 | 照明装置及び表示装置 |
CN112770431A (zh) * | 2019-10-21 | 2021-05-07 | 台湾爱司帝科技股份有限公司 | 发光模块 |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10247411A (ja) * | 1997-03-03 | 1998-09-14 | Omron Corp | 面光源装置 |
JPH11162233A (ja) * | 1997-11-25 | 1999-06-18 | Matsushita Electric Works Ltd | 光源装置 |
JP2003207780A (ja) * | 2002-01-16 | 2003-07-25 | Harison Toshiba Lighting Corp | バックライトユニット |
JP2005196989A (ja) * | 2003-12-26 | 2005-07-21 | Fujitsu Display Technologies Corp | バックライト及び液晶表示装置 |
WO2006006537A1 (ja) * | 2004-07-12 | 2006-01-19 | Sony Corporation | バックライトユニットの駆動装置及びその駆動方法 |
JP2006133721A (ja) * | 2004-10-08 | 2006-05-25 | Sony Corp | バックライト用光源ユニット、液晶表示用バックライト装置及び透過型カラー液晶表示装置 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102005063433B4 (de) * | 2004-10-29 | 2009-11-26 | Lg Display Co., Ltd. | Hintergrundbeleuchtungseinheit und Flüssigkristall-Anzeigevorrichtung |
JP4650085B2 (ja) * | 2005-04-27 | 2011-03-16 | ソニー株式会社 | バックライト装置及び液晶表示装置 |
US7431475B2 (en) * | 2005-07-22 | 2008-10-07 | Sony Corporation | Radiator for light emitting unit, and backlight device |
US7527408B2 (en) * | 2005-10-24 | 2009-05-05 | Lg Electronics Inc. | Backlight unit having heat dissipating layer, display device having heat dissipating layer, and method for manufacturing heat dissipating layer |
-
2006
- 2006-11-27 CN CN2006800537250A patent/CN101400940B/zh not_active Expired - Fee Related
- 2006-11-27 WO PCT/JP2006/323564 patent/WO2007138724A1/ja active Application Filing
- 2006-11-27 US US12/294,274 patent/US20090251922A1/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10247411A (ja) * | 1997-03-03 | 1998-09-14 | Omron Corp | 面光源装置 |
JPH11162233A (ja) * | 1997-11-25 | 1999-06-18 | Matsushita Electric Works Ltd | 光源装置 |
JP2003207780A (ja) * | 2002-01-16 | 2003-07-25 | Harison Toshiba Lighting Corp | バックライトユニット |
JP2005196989A (ja) * | 2003-12-26 | 2005-07-21 | Fujitsu Display Technologies Corp | バックライト及び液晶表示装置 |
WO2006006537A1 (ja) * | 2004-07-12 | 2006-01-19 | Sony Corporation | バックライトユニットの駆動装置及びその駆動方法 |
JP2006133721A (ja) * | 2004-10-08 | 2006-05-25 | Sony Corp | バックライト用光源ユニット、液晶表示用バックライト装置及び透過型カラー液晶表示装置 |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010032731A (ja) * | 2008-07-28 | 2010-02-12 | Panasonic Corp | バックライト装置 |
JP2010032730A (ja) * | 2008-07-28 | 2010-02-12 | Panasonic Corp | バックライト装置 |
US8284348B2 (en) * | 2008-07-28 | 2012-10-09 | Panasonic Corporation | Backlight apparatus and liquid crystal display apparatus |
CN101806414A (zh) * | 2009-02-17 | 2010-08-18 | Lg伊诺特有限公司 | 光源和具有该光源的显示设备 |
EP2218963A3 (en) * | 2009-02-17 | 2010-09-08 | LG Innotek Co., Ltd. | Light source and display device having the same |
US8408778B2 (en) | 2009-02-17 | 2013-04-02 | Lg Innotek Co., Ltd. | Light source and display device having the same |
Also Published As
Publication number | Publication date |
---|---|
CN101400940B (zh) | 2011-02-09 |
US20090251922A1 (en) | 2009-10-08 |
CN101400940A (zh) | 2009-04-01 |
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