WO2013088594A1 - Backlight apparatus and liquid crystal display apparatus - Google Patents

Backlight apparatus and liquid crystal display apparatus Download PDF

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Publication number
WO2013088594A1
WO2013088594A1 PCT/JP2012/004534 JP2012004534W WO2013088594A1 WO 2013088594 A1 WO2013088594 A1 WO 2013088594A1 JP 2012004534 W JP2012004534 W JP 2012004534W WO 2013088594 A1 WO2013088594 A1 WO 2013088594A1
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WO
WIPO (PCT)
Prior art keywords
liquid crystal
light
led
crystal panel
light source
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Application number
PCT/JP2012/004534
Other languages
French (fr)
Japanese (ja)
Inventor
義一 山野
久昇 佐々木
高原 一郎
友徳 水谷
Original Assignee
パナソニック株式会社
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Priority to JP2011274164A priority Critical patent/JP2015038812A/en
Priority to JP2011-274164 priority
Application filed by パナソニック株式会社 filed Critical パナソニック株式会社
Publication of WO2013088594A1 publication Critical patent/WO2013088594A1/en

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    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices 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
    • G02F1/01Devices 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 
    • G02F1/13Devices 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
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133611Direct backlight including means for improving the brightness uniformity
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices 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
    • G02F1/01Devices 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 
    • G02F1/13Devices 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
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133606Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices 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
    • G02F1/01Devices 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 
    • G02F1/13Devices 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
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133603Direct backlight with LEDs
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices 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
    • G02F1/01Devices 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 
    • G02F1/13Devices 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
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133606Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • G02F2001/133607Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

A backlight apparatus (12) has: a light source section (10), which has a plurality of LEDs (7) that emit light to the liquid crystal panel (2) side, and a lens section (5) that expands the light emitted from the LEDs (7); and a diffusion plate (4), which is disposed between a liquid crystal panel (2) and the light source section (10), and diffuses the light emitted from the LEDs (7). In the light source section (10), a plurality of LEDs (7) are arranged such that a plurality of rows of the LEDs (7) are formed. Among the LED rows, there are two LED rows (21, 22) respectively having main light emitting directions different from each other.

Description

Backlight device and liquid crystal display device

The present disclosure relates to a backlight device and a liquid crystal display device using an LED (Light Emitting Diode) as a light source.

In the backlight device of a conventional large liquid crystal display device, a large number of cold cathode tubes are arranged directly under the liquid crystal panel, and these cold cathode tubes are used together with members such as a diffusion plate and a reflector. In recent years, LEDs have been used as light sources for backlight devices. In recent years, the efficiency of LEDs has been improved and is expected to be a light source with low power consumption, which is replaced with a fluorescent lamp. When the LED is used as the light source of the liquid crystal display device, the power consumption of the liquid crystal display device can be reduced by controlling the brightness of the LED according to the image.

Also, by using a large number of LEDs in the liquid crystal display device, uniform brightness can be obtained on the screen of the liquid crystal display device. However, when many LEDs are used, there is a problem that the liquid crystal display device cannot be made inexpensive. Furthermore, efforts are being made to increase the output of one LED and reduce the number of LEDs used. For example, Patent Document 1 proposes a light source having a plurality of point light sources arranged in a one-dimensional manner and an elongated cylindrical lens provided on the plurality of point light sources.

JP 2006-286608 A

The present disclosure provides a backlight device and a liquid crystal display device capable of ensuring appropriate brightness while suppressing the number of LEDs used.

A backlight device according to the present disclosure is a backlight device that emits light from the back of a liquid crystal panel, and a plurality of LEDs that emit light toward the liquid crystal panel, and a lens unit that expands the light emitted from the plurality of LEDs And a light diffusing plate that is disposed between the liquid crystal panel and the light source unit and diffuses light emitted from the plurality of LEDs. In the light source unit, a plurality of LED rows are formed. A plurality of LEDs are arranged, and in the plurality of LED rows, there are two LED rows having different main emission directions of light.

The backlight device of the present disclosure is useful for ensuring appropriate brightness while suppressing the number of LEDs used.

FIG. 1 is an exploded perspective view showing a schematic configuration of the entire liquid crystal display device using the backlight device according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is a diagram illustrating a transmission state of light emitted from the LED according to the first embodiment. FIG. 4 is a diagram illustrating an example of the directivity characteristic of the emitted light of the LED. FIG. 5 is a diagram showing the intensity distribution of incident light on the entrance surface of the diffuser plate. FIG. 6 is a diagram showing a luminance distribution on the exit surface of the diffusion plate. FIG. 7 is a diagram illustrating an example of a pattern formed on the diffusion plate. FIG. 8 is a schematic configuration diagram of the liquid crystal panel of the liquid crystal display device according to Embodiment 2 as seen through from the front. FIG. 9 is a longitudinal sectional view of the liquid crystal display device according to the second embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

The inventor provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is intended to limit the subject matter described in the claims. is not.

(Embodiment 1)
The first embodiment will be described below with reference to FIGS.

[1-1. Configuration of liquid crystal display device]
FIG. 1 is an exploded perspective view showing an overall schematic configuration of a liquid crystal display device 11 using a backlight device 12 according to the present embodiment.

As shown in FIG. 1, the liquid crystal display device 11 includes a front frame 1, a rectangular flat plate-shaped transmissive liquid crystal panel 2, and a backlight device 12 disposed on the back side of the liquid crystal panel 2. . The backlight device 12 is formed in a rectangular parallelepiped shape having a size corresponding to the liquid crystal panel 2. The liquid crystal display device 11 includes a drive device that drives the liquid crystal panel 2 based on the video signal, but the description thereof is omitted in the present embodiment.

The liquid crystal panel 2 is disposed in front of the backlight device 12 and transmits light emitted from the backlight device 12. The front frame 1 is formed in a rectangular frame shape. Inside the front frame 1, a liquid crystal panel 2 and the like are provided.

[1-2. Configuration of backlight device]
The backlight device 12 includes a light source unit 10 that is linearly disposed at a substantially central portion in the short side direction of the liquid crystal panel 2, a rear frame 9 that accommodates the light source unit 10, and the liquid crystal panel 2 and the light source unit 10. Reflection that reflects the light radiated from the diffusion plate 4 disposed between, the diffusion sheet 3 disposed between the diffusion plate 4 and the liquid crystal panel 2, and the light source unit 10 toward the liquid crystal panel 2 side, that is, the diffusion plate 4 side. And a sheet 8. The light emission surface of the diffusion sheet 3 (the surface on the liquid crystal panel 2 side) is the light emission surface of the backlight device 12.

The diffusion plate 4 performs diffusion for reducing uneven brightness of light emitted from the light source unit 10. The diffusion plate 4 is made of a plate-like body such as an acrylic resin. The diffusing plate 4 has dispersed minute particles in order to diffuse the light incident from one surface (incident surface on the light source unit 10 side) and emit the light from the other surface (emitted surface on the liquid crystal panel 2 side). It is composed of a translucent resin plate.

The diffusion sheet 3 is a rectangular sheet. The diffusion sheet 3 has a size corresponding to the liquid crystal panel 2 and is disposed between the liquid crystal panel 2 and the diffusion plate 4. The diffusion sheet 3 includes an optical sheet laminate. This optical sheet laminate includes, for example, a prism sheet that condenses light incident from the diffusion plate 4 side toward the front liquid crystal panel 2 side, a diffusion sheet that further diffuses light incident from the diffusion plate 4 side, and a diffusion sheet 3 is constituted by a polarizing sheet or the like that transmits light having a specific polarization plane so that the polarization plane of the light emitted from 3 corresponds to the polarization plane of the liquid crystal panel 2.

The rear frame 9 and the front frame 1 constitute a casing of the liquid crystal display device 11. The rear frame 9 has a substantially rectangular shape when viewed from the front. A mountain-shaped substrate installation surface 9 a for installing two printed circuit boards 6 to be described later is formed along the longitudinal direction of the rear frame 9 at the central portion in the short direction of the rear frame 9. The reflection sheet 8 is provided in front of the rear frame 9 over almost the entire area except for the installation area of the plurality of LEDs 7. The reflection surface of the reflection sheet 8 has a concave curved surface so that the light emitted from the light source unit 10 can be efficiently and uniformly reflected to the diffusion plate 4 side.

[1-3. Configuration of light source section]
FIG. 2 is a cross-sectional view taken along the line AA in FIG.

The light source unit 10 includes a plurality of LEDs 7 that emit light toward the liquid crystal panel 2, an LED installation unit 6 that has an LED installation surface 6 a, and a lens unit 5 that expands the light emitted from the plurality of LEDs 7. . The light source unit 10 according to the present embodiment includes two printed circuit boards 6 each corresponding to the LED installation unit 6, a plurality of LEDs 7 mounted in a row on each printed circuit board 6, and a Fresnel corresponding to the lens unit 5. And a lens 5. In the light source unit 10, a plurality of LEDs 7 are arranged so that a plurality of LED rows 21 and 22 are formed. Each printed circuit board 6 is formed in a strip shape, that is, an elongated rectangular shape.

In the present embodiment, the number of LED rows 21 and 22 in the light source unit 10 is two. The number of LED rows is not limited to two. The two LED rows 21 and 22 are the first LED row 21 mounted on the first printed circuit board 6 (the left printed circuit board 6 in FIG. 2) and the second printed circuit board 6 (the right printed circuit board in FIG. 2). And the second LED row 22 mounted on the printed circuit board 6). Each LED row 21, 22 is mounted on the LED installation surface 6 a on the liquid crystal panel 2 side of the corresponding printed circuit board 6. The LED rows 21 and 22 are mounted such that the main radiation direction of light of each LED 7 (the direction with the largest relative illuminance) is substantially perpendicular to the LED installation surface 6a. The main radiation direction of the light of the LED 7 may be inclined to some extent with respect to the vertical without being substantially perpendicular to the LED installation surface 6a.

The Fresnel lens 5 is disposed between the liquid crystal panel 2 and the LED 7. The Fresnel lens 5 is installed on the rear frame 9 so as to cover the two LED rows 21 and 22. The Fresnel lens 5 extends in the longitudinal direction of the liquid crystal panel 2. In the present embodiment, one Fresnel lens 5 is disposed in front of the plurality of LEDs 7 so as to cover all the LEDs 7. The Fresnel lens 5 expands and emits the light emitted from the LED 7. Specifically, the Fresnel lens 5 extends the liquid crystal panel 2 in the short direction with respect to the light emitted from the two LED rows 21 and 22. The Fresnel lens 5 is made of a transparent material having a refractive index of about 1.4 to 2.0, for example. As the transparent material constituting the Fresnel lens 5, epoxy resin, silicon resin, acrylic resin, polycarbonate resin or the like, glass, or rubber such as silicon rubber can be used.

The two printed circuit boards 6 are disposed at substantially central portions in the short side direction of the liquid crystal panel 2 in a state of being inclined in different directions with respect to the main surface (front surface and back surface) of the liquid crystal panel 2. The two printed circuit boards 6 are arranged along the longitudinal direction of the liquid crystal panel 2. In each LED row 21, 22, a plurality of LEDs 7 are arranged in the longitudinal direction of the liquid crystal panel 2. The two printed circuit boards 6 have two LED rows 21 and 22 (LED groups) in which LEDs 7 are arranged in a row at substantially the center in the short side direction of the liquid crystal panel 2. The two printed circuit boards 6 are arranged on the main surface of the liquid crystal panel 2 so that the main emission direction of the light in the first LED row 21 and the main emission direction of the light in the second LED row 22 are different from each other. On the other hand, they are arranged in an inclined state in different directions. The 1st printed circuit board 6 and the 2nd printed circuit board 6 are arrange | positioned in parallel on the different slope of the mountain-shaped board | substrate installation surface 9a. The first printed circuit board 6 and the second printed circuit board 6 are inclined in the opposite direction by the same angle with respect to the main surface of the liquid crystal panel 2. The first printed circuit board 6 and the second printed circuit board 6 are adjacent to each other. The first LED row 21 is arranged closer to the first side 2 a than the second LED row 22. In the light source unit 10, the main radiation directions of the light in the two LED rows 21 and 22 are made different from each other by making the directions of the LED installation surfaces 6 a of the two printed circuit boards 6 different from each other. In the two LED rows 21 and 22, the main radiation direction of the light in the first LED row 21 is closer to the first long side 2 a (first side) of the liquid crystal panel 2 than the thickness direction of the liquid crystal panel 2. The main radiation direction of the light in the second LED row 22 is inclined to the second long side 2b (second side) side of the liquid crystal panel 2 with respect to the thickness direction of the liquid crystal panel 2.

FIG. 3 is a diagram showing a transmission state (light trajectory) of light emitted by the LED 7 according to the present embodiment. FIG. 3 is a cross-sectional view taken along line AA of FIG. In FIG. 3, the light of the LED 7 is indicated by an arrow. FIG. 4 is a diagram illustrating an example of the directivity characteristic of the emitted light of the LED 7.

The light having the directivity shown in FIG. 4 is emitted from the LED 7 shown in FIG. In FIG. 4, the direction with the maximum relative illuminance and the radiation angle of 0 ° is the main radiation direction of the emitted light of the LED 7. In FIG. 3, the left LED 7 is an LED in the first LED row 21, and the right LED 7 is an LED in the second LED row 22. As shown in FIG. 3, the LEDs 7 in the LED rows 21 and 22 are arranged to emit light in different directions.

Most of the light emitted from the LED 7 is directly incident on the Fresnel lens 5. On the other hand, a part of the light emitted from the LED 7 is reflected by the incident surface of the Fresnel lens 5, but is reflected again by the reflection sheet 8 and enters the Fresnel lens 5. The light incident on the Fresnel lens 5 is expanded according to the optical shape and the refractive index. Most of the light emitted from the Fresnel lens 5 is directly incident on the diffusion plate 4. On the other hand, a part of the light emitted from the Fresnel lens 5 is reflected by the incident surface of the diffusion plate 4, but is reflected by the reflection sheet 8 again and enters the diffusion plate 4. In the diffusing plate 4, diffusion for reducing luminance unevenness is performed. Light emitted from the diffusion plate 4 enters the diffusion sheet 3. In the diffusion sheet 3, light condensing toward the liquid crystal panel 2 side, diffusion, correspondence to the polarization plane, and the like are performed. The light emitted from the diffusion sheet 3 enters the liquid crystal panel 2 and is modulated by a video signal or the like to form an image.

[1-4. Diffusion plate]
Next, the pattern formed on the diffusion plate 4 will be described.

FIG. 5 is a diagram showing the intensity distribution of incident light on the incident surface of the diffuser plate 4. FIG. 6 is a diagram showing a luminance distribution of outgoing light on the outgoing surface of the diffusion plate 4. 5 and 6, the lighter the position, the stronger the light intensity or the higher the luminance. FIG. 7 is a diagram illustrating an example of a pattern formed on the diffusion plate 4. The intensity distribution of incident light on the incident surface of the diffusion plate 4 corresponds to the luminance distribution of light immediately before entering the diffusion plate 4. The luminance distribution of the emitted light on the exit surface of the diffusion plate 4 corresponds to the luminance distribution of the light immediately after being emitted from the diffusion plate 4.

The diffuser plate 4 of the present embodiment is configured such that the light transmittance in the thickness direction of the diffuser plate 4 becomes relatively smaller as the incident light intensity on the incident surface on the light source unit 10 side is higher. . That is, in the diffuser plate 4, the position where the intensity of incident light on the incident surface is high has a small light transmittance in the thickness direction of the diffuser plate 4, and the position where the intensity of incident light on the incident surface is weak is the diffuser plate 4. The light transmittance in the thickness direction is large. In the diffusing plate 4, as shown in FIG. 7, the luminance distribution of the exit surface of the diffusing plate 4 is inverted with respect to the intensity distribution of incident light on the incident surface so that the luminance distribution has almost no unevenness as shown in FIG. Pattern (that is, a pattern having a darker color in a lighter region in FIG. 5) is formed. This pattern is formed on the entrance surface or the exit surface of the diffusion plate 4 by, for example, screen printing. As a result, luminance unevenness on the exit surface of the diffusion plate 4 is reduced. Therefore, it is possible to realize a backlight device 12 of a surface light source that reduces luminance unevenness on the screen of the liquid crystal panel 2 using light emitted from the LED 7. For pattern printing, ink in which fine powder made of a transparent material having a high refractive index such as titanium oxide is dispersed in a transparent binder is used. A pattern with a low transmittance (a pattern that has a large influence on the passing light beam in FIG. 7) is used at a location where the intensity of the incident light is strong, and a pattern with a high transmittance (a passing light beam in FIG. Small pattern).

[1-5. Effects of this embodiment]
As described above, in the present embodiment, in the backlight device 12 using the LED 7, each of the two LED rows 21 and 22 is different from the main surface of the liquid crystal panel 2 so that the main emission directions of light are different from each other. The printed circuit board 6 is inclined. Therefore, it is possible to provide the liquid crystal display device 11 that can ensure appropriate brightness while suppressing the number of LEDs 7 used. Further, since the number of LEDs 7 used can be suppressed, it is possible to provide an inexpensive liquid crystal display device 11 with a simple configuration.

Further, in the present embodiment, a pattern (printing pattern) that can make the intensity distribution of the light reaching the liquid crystal panel 2 uniform with respect to the intensity distribution of the light from the LED 7 reaching the diffusion plate 4 is a diffusion plate. 4 is formed. Therefore, it is possible to further reduce luminance unevenness on the light emission surface of the backlight device 12.

(Embodiment 2)
The second embodiment will be described below with reference to FIGS.

FIG. 8 is a schematic configuration diagram of the liquid crystal panel 2 of the liquid crystal display device 11 according to Embodiment 2 as seen through from the front. FIG. 9 is a longitudinal sectional view of the liquid crystal display device 11.

In the present embodiment, as shown in FIG. 8, the liquid crystal panel 2 is divided into two rectangular areas 31 and 32. In the first rectangular area 31 on the left side, a first light source unit 10a is provided. In the second rectangular area 32 on the right side, the second light source unit 10b is provided. Each of the light source units 10 a and 10 b includes a first LED row 21, a second LED row 22, a printed circuit board 6 provided in each LED row 21, 22, and a Fresnel lens 5. . The first LED row 21 is provided along the longitudinal direction of the first rectangular region 31 in the center of the first rectangular region 31 in the short direction. The second LED row 22 is provided along the longitudinal direction of the second rectangular region 32 in the center of the second rectangular region 32 in the short direction. The Fresnel lens 5 is disposed so as to cover all the LEDs 7 of the light source units 10a and 10b to which the Fresnel lens 5 belongs. The Fresnel lens 5 extends the rectangular regions 31 and 32 in the short direction with respect to the light emitted from the two LED rows 21 and 22.

Each LED row 21, 22 is mounted on the LED installation surface 6 a on the liquid crystal panel 2 side of each printed circuit board 6. The first printed circuit board 6 on which the first LED array 21 is mounted is different from the second printed circuit board 6 on which the second LED array 22 is mounted on the mountain-shaped substrate mounting surface 9 a of the rear frame 9. It is arranged parallel to the slope.

In each of the rectangular regions 31 and 32, the main radiation direction of the light in the first LED row 21 is inclined toward the first short side 2 c (first side) of the liquid crystal panel 2 with respect to the thickness direction of the liquid crystal panel 2. The main radiation direction of the light in the second LED row 22 is tilted toward the second short side 2d (second side) of the liquid crystal panel 2 with respect to the thickness direction of the liquid crystal panel 2. The main radiation direction of the light in the first LED row 21 in the first rectangular area 31 is the same as the main radiation direction of the light in the first LED row 21 in the second rectangular area 32. The main radiation direction of the light in the second LED row 22 in the first rectangular region 31 is the same as the main radiation direction of the light in the second LED row 22 in the second rectangular region 32.

[Effects of this embodiment, etc.]
As described above, in the present embodiment, it is possible to provide the liquid crystal display device 11 that can ensure appropriate brightness while suppressing the number of LEDs 7 used. Further, since the number of LEDs 7 used can be suppressed, it is possible to provide an inexpensive liquid crystal display device 11 with a simple configuration.

Further, the backlight device 12 divides the liquid crystal panel 2 into two rectangular areas 31 and 32 to emit light. Therefore, the thickness of the liquid crystal display device 11 can be reduced as compared with the case where the backlight device 12 emits light with the liquid crystal panel 2 as one region.

(Reference form of Embodiment 2)
In the reference mode, as in the second embodiment, the backlight device 12 divides the liquid crystal panel 2 into a plurality of rectangular areas 31 and 32 (for example, two rectangular areas) and emits light. The rectangular regions 31 and 32 are provided with light source units 10a and 10b, respectively. Each light source unit is provided along the longitudinal direction of the corresponding rectangular region at the center in the short direction of the corresponding rectangular region. In each light source unit, a plurality of LEDs are arranged so that a plurality of LED rows are formed. In the reference mode, unlike the second embodiment, the main radiation direction of the light of all the LED columns of each light source unit is directed in the thickness direction of the liquid crystal panel 2. Each light source unit expands the rectangular region in the short direction with respect to the light emitted from the plurality of LED columns by the lens unit 5 (for example, Fresnel lens), so that the light source unit faces the rectangular region that the light source unit faces. Light is supplied not only to the central portion but also to both short sides of the rectangular area.

(Other embodiments)
As described above, Embodiments 1 and 2 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. In addition, it is possible to combine the components described in the first and second embodiments to form a new embodiment.
Therefore, other embodiments will be exemplified below.

In the first and second embodiments, arranging a plurality of LEDs 7 in a row indicates that the LEDs 7 need only be arranged in a row. That is, in each LED row 21 and 22, a plurality of LEDs 7 are arranged in a straight line, but in each LED row 21 and 22, a plurality of LEDs 7 are slightly shifted from the straight line in the direction perpendicular to the straight line. May be.

In the first and second embodiments, the number of LED rows of the light source unit 10 is two, but the number of LED rows of the light source unit 10 may be three or more. For example, in the case of three rows, the interval between the two LED rows 21 and 22 described in the first and second embodiments is widened, and the liquid crystal panel 2 is placed between these LED rows 21 and 22. One LED row (third LED row) arranged on the LED installation surface parallel to the main surface is provided. Also in this case, the inclination of each LED installation surface may be adjusted so that the main emission directions of the three LED columns are different from each other.

In the first and second embodiments, two printed circuit boards 6 are installed on the mountain-shaped board installation surface 9a, but two printed circuit boards 6 may be installed on the valley-shaped board installation surface 9a.

In the first and second embodiments, one lens 5 for expanding light is used for the plurality of LED rows 21 and 22. However, you may provide the lens 5 which expands light for every LED7 or every row | line | columns 21 and 22 of LED.

In the first and second embodiments, the diffusion sheet 3 (thin diffusion plate) and the diffusion plate 4 are used for light diffusion. However, only one of them or another diffusion member may be used. May be.

In the first and second embodiments, the Fresnel lens 5 is described as an example of the lens unit 5. However, the lens unit 5 is not limited to this. The lens unit 5 may be another type of lens that expands light.

Further, in the first and second embodiments, the reflection sheet 8 has been described as an example of the reflection unit that reflects the light emitted from the light source unit 10 to the side thereof toward the liquid crystal panel 2 side. However, the reflection part is not limited to this. The reflecting portion may be another reflecting mirror or a reflecting member having a color that easily reflects light such as white.

As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to exemplify the above technique. Elements can also be included. Therefore, just because those non-essential components are described in the accompanying drawings and detailed description, the non-essential components should not be recognized as essential.

In addition, since the above-described embodiment is for illustrating the technique in the present disclosure, various modifications, replacements, additions, omissions, and the like can be performed within the scope of the claims or an equivalent scope thereof.

As described above, the present disclosure is useful in obtaining a backlight device, a liquid crystal display device, and the like that can ensure appropriate brightness while suppressing the number of LEDs used.

1 Front frame 2 Liquid crystal panel 3 Diffusion sheet 4 Diffusion plate 5 Fresnel lens 6 Printed circuit board (LED installation part)
6a LED installation surface 7 LED
DESCRIPTION OF SYMBOLS 8 Reflective sheet 9 Rear frame 10 Light source part 11 Liquid crystal display device 12 Backlight apparatus 21 1st LED row | line | column 22 2nd LED row | line | column

Claims (18)

  1. A backlight device that emits light from the back of a liquid crystal panel,
    A light source unit having a plurality of LEDs that emit light toward the liquid crystal panel, and a lens unit that expands the light emitted from the plurality of LEDs;
    A diffusion plate that is disposed between the liquid crystal panel and the light source unit and diffuses light emitted from the plurality of LEDs;
    In the light source unit, the plurality of LEDs are arranged so that a plurality of LED rows are formed,
    2. The backlight device according to claim 1, wherein in the plurality of LED rows, there are two LED rows having different main emission directions of light.
  2. The light source unit has an LED installation surface for installing the LED for each row of the LEDs,
    2. The backlight device according to claim 1, wherein in the two LED rows, the main radiation directions of light are made different from each other by making directions of the LED installation surfaces different from each other.
  3. 2. The backlight device according to claim 1, wherein in the light source unit, the number of the LED rows is two, and main light emission directions of the two LED rows are different from each other.
  4. In the two LED rows, the main radiation direction of the light of one first LED row is inclined toward the first side of the liquid crystal panel with respect to the thickness direction of the liquid crystal panel, and the other second LED 2. The back according to claim 1, wherein a main radiation direction of light in the first column is inclined toward a second side opposite to the first side in the liquid crystal panel with respect to a thickness direction of the liquid crystal panel. Light equipment.
  5. The backlight device according to claim 4, wherein the first LED row is disposed closer to the first side than the second LED row.
  6. The diffuser plate is configured such that the light transmittance in the thickness direction of the diffuser plate becomes relatively smaller as the intensity of incident light on the surface on the light source unit side is higher. The backlight device according to 1.
  7. The backlight device according to claim 1, wherein the lens unit includes one lens that expands light emitted from the row of the plurality of LEDs.
  8. 2. The backlight device according to claim 1, wherein the plurality of LED rows are provided along a longitudinal direction of the liquid crystal panel at a central portion in a short direction of the liquid crystal panel having a rectangular plate shape. .
  9. The backlight device radiates light by dividing the liquid crystal panel into a plurality of rectangular regions,
    The light source unit is provided for each rectangular area,
    2. The light source unit according to claim 1, wherein the plurality of LED rows are respectively provided in a central portion in a short direction of each rectangular region along a longitudinal direction of each rectangular region. Backlight device.
  10. LCD panel,
    A backlight device disposed on the back side of the liquid crystal panel,
    The backlight device includes:
    A light source unit having a plurality of LEDs that emit light toward the liquid crystal panel, and a lens unit that expands the light emitted from the plurality of LEDs;
    A diffusion plate that is disposed between the liquid crystal panel and the light source unit and diffuses light emitted from the plurality of LEDs;
    In the light source unit, the plurality of LEDs are arranged so that a plurality of LED rows are formed,
    2. The liquid crystal display device according to claim 1, wherein in the plurality of LED rows, there are two LED rows having different main light emission directions.
  11. The light source unit has an LED installation surface for installing the LED for each row of the LEDs,
    11. The liquid crystal display device according to claim 10, wherein in the two LED rows, the main radiation directions of light are made different from each other by making directions of the LED installation surfaces different from each other.
  12. 11. The liquid crystal display device according to claim 10, wherein in the light source unit, the number of the LED rows is two, and main light emission directions of the two LED rows are different from each other.
  13. In the two LED rows, the main radiation direction of the light of one first LED row is inclined toward the first side of the liquid crystal panel with respect to the thickness direction of the liquid crystal panel, and the other second LED 11. The back according to claim 10, wherein a main radiation direction of light in the column is inclined toward a second side opposite to the first side in the liquid crystal panel with respect to a thickness direction of the liquid crystal panel. Light equipment.
  14. 14. The liquid crystal display device according to claim 13, wherein the first LED row is arranged closer to the first side than the second LED row.
  15. The diffuser plate is configured such that the light transmittance in the thickness direction of the diffuser plate becomes relatively smaller as the intensity of incident light on the surface on the light source unit side is higher. 10. A liquid crystal display device according to 10.
  16. The liquid crystal display device according to claim 10, wherein the lens unit includes one lens that expands light emitted from the plurality of LED rows.
  17. 11. The liquid crystal display device according to claim 10, wherein the plurality of LED rows are provided along a longitudinal direction of the liquid crystal panel at a central portion in a short direction of the liquid crystal panel having a rectangular plate shape. .
  18. The backlight device radiates light by dividing the liquid crystal panel into a plurality of rectangular regions,
    The light source unit is provided for each rectangular area,
    The said light source part WHEREIN: The row | line | column of these LED is provided in the center part of the transversal direction of each said rectangular area along the longitudinal direction of each said rectangular area, respectively. Liquid crystal display device.
PCT/JP2012/004534 2011-12-15 2012-07-13 Backlight apparatus and liquid crystal display apparatus WO2013088594A1 (en)

Priority Applications (2)

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JP2011-274164 2011-12-15

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106125396A (en) * 2015-05-08 2016-11-16 三星电子株式会社 Display device
CN107884992A (en) * 2017-12-26 2018-04-06 惠州市华星光电技术有限公司 The backlight module and display device of low cost
US10802332B2 (en) 2017-12-26 2020-10-13 Huizhou China Star Optoelectronics Technology Co., Ltd. Low cost backlight module and display device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001312916A (en) * 2000-02-24 2001-11-09 Sony Corp Surface light source device
JP2004319458A (en) * 2003-03-31 2004-11-11 Fujitsu Display Technologies Corp Plane lighting device, and liquid crystal display device using the same
JP2007134224A (en) * 2005-11-11 2007-05-31 Showa Denko Kk Plane light source device and display device
JP2007328309A (en) * 2006-06-06 2007-12-20 Mikuni Denshi Kk Surface light source device, prism sheet and liquid crystal display device
WO2010029801A1 (en) * 2008-09-11 2010-03-18 シャープ株式会社 Illuminating device and liquid crystal display device provided with the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001312916A (en) * 2000-02-24 2001-11-09 Sony Corp Surface light source device
JP2004319458A (en) * 2003-03-31 2004-11-11 Fujitsu Display Technologies Corp Plane lighting device, and liquid crystal display device using the same
JP2007134224A (en) * 2005-11-11 2007-05-31 Showa Denko Kk Plane light source device and display device
JP2007328309A (en) * 2006-06-06 2007-12-20 Mikuni Denshi Kk Surface light source device, prism sheet and liquid crystal display device
WO2010029801A1 (en) * 2008-09-11 2010-03-18 シャープ株式会社 Illuminating device and liquid crystal display device provided with the same

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106125396A (en) * 2015-05-08 2016-11-16 三星电子株式会社 Display device
CN107884992A (en) * 2017-12-26 2018-04-06 惠州市华星光电技术有限公司 The backlight module and display device of low cost
WO2019127784A1 (en) * 2017-12-26 2019-07-04 惠州市华星光电技术有限公司 Low-cost backlight module and display apparatus
US10802332B2 (en) 2017-12-26 2020-10-13 Huizhou China Star Optoelectronics Technology Co., Ltd. Low cost backlight module and display device

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