JP2001183665A - Liquid crystal display - Google Patents

Abstract

(57) [Object] To provide a liquid crystal display device with low power consumption and good white balance. A liquid crystal panel includes a pair of substrates, a plurality of electrodes formed on at least one of the pair of substrates, and a liquid crystal layer sandwiched between the pair of substrates, and a back surface of the liquid crystal panel for an observer. The light source has a light emission characteristic of warm color chromaticity, and the liquid crystal panel has a spectral transmittance characteristic of cool color chromaticity. And a liquid crystal display device that compensates for the color of the light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an active matrix type liquid crystal display device.

[0002]

2. Description of the Related Art A method using a pair of comb electrodes is used to make the direction of an electric field applied to a liquid crystal substantially parallel to the substrate surface.
For example, Japanese Patent Publication No. 63-21907, US Pat. No. 4,345,249, WO 91/109
No. 36, JP-A-6-222397 and the like. However, in a display system in which the direction of the electric field applied to the liquid crystal by using the active element is made substantially parallel to the substrate surface (hereinafter referred to as a horizontal electric field system), it is necessary to reduce the power consumption of the entire liquid crystal display device. Are not mentioned.

[0003]

In the horizontal electric field method, an opaque electrode is provided in the display pixel portion in order to apply an electric field substantially parallel to the substrate surface. Therefore, as compared with the conventional method of applying an electric field using a transparent electrode in a direction substantially perpendicular to the substrate surface (hereinafter referred to as a vertical electric field method), the aperture ratio is reduced, and the brightness in a bright state is reduced. Because
A high-intensity light source is required.

On the other hand, since the effective display mode in a horizontal electric field type liquid crystal display device is a birefringence mode, the transmittance T is generally

[0005]

(Equation 1)

[0006] Here, T ₀ is mainly determined by the transmittance of the polarizing plate, θ is the angle between the effective optical axis of the liquid crystal layer and the polarization transmission axis, d is the thickness of the liquid crystal layer, Δn is the refractive index anisotropy of the liquid crystal, λ represents the wavelength of light. Therefore, since the transmittance of the liquid crystal display element always takes the maximum value at a certain wavelength, the liquid crystal display element is colored. One solution is that the zero-order retardation sets the peak wavelength to 555 nm, which is the maximum wavelength of luminosity, that is, the condition that (πd · Δn / 555) = π / 2 is satisfied. However, at this time,
As shown in FIG. 2, the transmittance sharply drops on the short wavelength side of the peak wavelength and gradually decreases on the long wavelength side, so that the liquid crystal display element is colored yellow. As described above, the light source is required to have a cool color system that is a complementary color of yellow, that is, a characteristic having a high color temperature.

[0007] Generally, a fluorescent tube is used as a light source for a liquid crystal display device. As a characteristic of the phosphor, the luminous efficiency in the short wavelength region is inferior to that in the long wavelength region. Therefore, a fluorescent tube having a high color temperature has reduced luminance. There is a problem that it increases. Particularly in a notebook personal computer and a portable information device, an increase in power consumption must be avoided in order to enable long-term use with a battery.

An object of the present invention is to provide a liquid crystal display device which has both low power consumption and good display characteristics.

[0009]

A liquid crystal display device according to the present invention has a pair of substrates, a plurality of electrodes formed on at least one of the pair of substrates, and a liquid crystal layer sandwiched between the pair of substrates. The liquid crystal panel is composed of a liquid crystal panel and a light source provided on the back of the liquid crystal panel with respect to an observer. The light source has a light emission characteristic of a warm color chromaticity, and the liquid crystal panel has a cool color chromaticity. And compensates for the color of the light source.

Here, the warm color system refers to a hue that gives a reddish hue such as yellow or orange to the standard C light source “white”, and the cool color system refers to a standard C light source. It refers to a hue that gives bluish hue to "white". The light source of the warm color system has low transmittance on the short wavelength side, and the liquid crystal panel of the cool color system has low transmittance on the long wavelength side.By combining them, the light in the visible light region is transmitted almost uniformly, The display of the entire liquid crystal display is standard C
Try to get closer to the “white” of the light source.

The present invention makes it possible to reduce the power consumption. The reason will be described below. A warm-color fluorescent lamp requires less power consumption to obtain the same brightness as a cool-color fluorescent lamp. Generally, assuming that the power consumption of a fluorescent lamp with a color temperature of 6000K is 1, the power consumption required to obtain the same luminance is 5%, 10,000 for a fluorescent lamp of 8000K.
At K, it increases by 10%, and at 4000K, it decreases by 5%. For example, a liquid crystal display element colored yellow has a color temperature higher than at least the color temperature of the standard light source C light source (white color) of 6770 K, and in order to compensate for color, it is preferable to use a light source of 10,000 K or more. There is a need. For example,
In a vertical electric field type liquid crystal display device, when a power consumption of 2 W is required as a light source using an 8700K fluorescent lamp, in a configuration of a horizontal electric field type liquid crystal display device using a color temperature of 10000K, a light source is required. The power consumption is 2.06 W, which is lower than the color temperature of the C light source (white).
For a 000K fluorescent lamp, 1.87W is sufficient,
At 0K, power consumption of 1.79W is sufficient.

A warm color light source can be obtained by changing the type of phosphor and the mixing ratio. In the case of a narrow-band light-emitting fluorescent lamp, the fluorescent lamp has an emission peak at 450 to 490 nm, 3Ca ₃ (PO ₄ ) ₂ .Ca (F, Cl) ₂ : Sb ³⁺ ,
Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO ₄ )
₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO ₄ ) ₆ Cl ₂ .nB
₂ O ₃ : Eu ²⁺ , (Ba, Ca, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ :
Eu ²⁺ , Sr ₂ P ₂ O ₇ : Sn ²⁺ , Ba ₂ P ₂ O ₇ : Ti
^{_{4+, 2SrO · 0.84P 2 O 5}} · 0.16B 2 O 3: Eu
²⁺ , MgWO ₄ , BaAl ₈ O ₁₃ : Eu ²⁺ , BaMg ₂ A
l ₁₆ O ₂₇ : Eu ²⁺ , BaMg ₂ Al ₁₆ O ₂₇ : Eu ² + Mn
A phosphor such as ²⁺ , SrMgAl ₁₀ O ₁₇ : Eu ²⁺
LaPO ₄ : Ce having an emission peak at ５550 nm
_{^{3+, Tb 3+, LaO 3 ·}} 0.2SiO 2 · 0.9P 2 O 5:
Ce ³⁺ , Tb ³⁺ , Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ , CeM
gAl ₁₁ O ₁₉ : Tb ³⁺ , GdMgB ₅ O ₁₀ : Ce ³⁺ , T
a phosphor such as b ³⁺ , and (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn ²⁺ , CaSiO ₃ having an emission peak near 610 nm:
Pb ²⁺ , Mn ²⁺ , Y ₂ O ₃ : Eu ³⁺ , Y (P, V) O ₄ :
It is made by mixing phosphors such as Eu ³⁺ . By changing these mixing ratios, the relative intensity in each light emitting region is controlled, and a fluorescent lamp having various color temperatures can be realized. In order to obtain a warm color fluorescent lamp having a low color temperature, 610n
What is necessary is just to increase the mixing ratio of the phosphor which has a light emission peak near m.

To realize a cool liquid crystal display panel,
There are the following three methods. (1) In order to obtain the characteristic of a cool color system, the transmittance should be maximum in a short wavelength region. Since the emission wavelength of the phosphor corresponding to green is 540 to 550 nm and the emission wavelength corresponding to blue is 450 to 490 nm, if the wavelength at which the transmittance becomes the maximum is 520 nm or less, the color tone of blue is increased. As a result, a cool-color liquid crystal display device can be obtained. For this purpose, d · Δn may be set to 0.26 or less according to the equation (1). In this case, d indicates the thickness (d _eff ) of the liquid crystal layer that changes the alignment direction when a voltage is applied. Liquid crystal molecules in the vicinity of the interface of the liquid crystal layer do not change the orientation direction even when a voltage is applied due to the influence of anchoring at the interface. Assuming that the liquid crystal layer sandwiched by the substrates is d _LC and the liquid crystal layer that changes the alignment direction when a voltage is applied is d _eff , d _eff <d _LC , and the difference is considered to be approximately 300 to 400 nm. (2) The liquid crystal display panel is provided with a birefringent film. In the birefringent film, the peak wavelength of the light transmission spectrum of the liquid crystal display panel is 400 to 520 in the short wavelength region of visible light.
nm, preferably in the range of 440 to 490 nm. (3) of the site to the display of the red color filter the thickness of the liquid crystal layer blue, thinner than d _LC of the green site.

The threshold voltage Ec of the horizontal electric field type liquid crystal display device
Is

[0015]

(Equation 2)

## EQU1 ## Here, d _LC is the thickness of the liquid crystal layer, K ₂ is the twist elastic constant of the liquid crystal, Δε is the dielectric anisotropy of the liquid crystal, and ε ₀ is the dielectric constant of a vacuum. Therefore, d _LC
Becomes thinner, the threshold voltage shifts to the higher voltage side.
Therefore, the voltage-transmittance characteristic in red, that is, in a long wavelength region can be shifted to a higher voltage side by setting the thickness of the liquid crystal layer to be thin in only the pixel portion for displaying red. For this reason, the transmittance at each voltage is such that the transmittance in the long wavelength region is suppressed and the liquid crystal display element has a large transmittance in the short wavelength region. In order to sufficiently suppress the transmittance in the long-wavelength region and not to disturb the color balance too much, the change in the thickness of the liquid crystal layer is preferably in the range of 0.1 to 1 μm. For example, by making the film thickness of the red portion of the color filter, it is possible to reduce the d _LC. Further, the thickness of the liquid crystal layer of the portion to the display of the blue color filter red, may be thicker than d _LC of the green parts. Also in this case, the change in the thickness of the liquid crystal layer is preferably in the range of 0.1 to 1 μm.

In the case of a conventional TN (twisted nematic) type liquid crystal display device in which an electric field is applied to a substrate in a vertical direction (vertical electric field type), the degree of coloring is low and the liquid crystal panel is positively colored. Can not do.

[0018]

For DETAILED DESCRIPTION OF THE INVENTION The field direction, showing the angle Φp polarization transmission axis of the polarizer, the liquid crystal molecular long axis near the interface definition of the angle [Phi _LC (optical axis) direction in FIG. 3. Since there are a pair of upper and lower interfaces between the polarizing plate and the liquid crystal, they are represented as Φp ₁ , Φp ₂ , Φ _LC1 , and Φ _LC2 as necessary.

FIGS. 4A and 4B are side sectional views showing the operation of the liquid crystal within one pixel of the in-plane switching mode liquid crystal display device.
(C) and (d) show the front view. FIG. 4A is a sectional side view of the device when no voltage is applied, and FIG. 4C is a front view at that time.
Shown in Linear electrodes 1, 3, inside a pair of transparent substrates
4 is formed thereon, and an orientation control film 5 is applied and oriented thereon. A liquid crystal composition is sandwiched between the two. The liquid crystal molecules 6 have 45 degrees <| Φ _LC | ≦ 90 when no electrolysis is applied.
Oriented to have degrees. Here, the liquid crystal molecule alignment on the upper and lower interfaces is parallel, that is, Φ _LC1 = Φ _LC2 . Further, the dielectric anisotropy of the liquid crystal composition is assumed to be positive. When the electric field 9 is applied, the liquid crystal molecules change their directions in the direction of the electric field as shown in FIGS. 4B and 4D. By disposing the polarizing plate 8 on the polarizing plate transmission axis 11, it becomes possible to change the light transmittance by applying an electric field. In addition,
There is no problem even if the dielectric anisotropy of the liquid crystal composition is negative. In that case the initial alignment state 0 ° <| orienting such that ≦ 45 ° | [Phi _LC.

Two glass substrates having a thickness of 1.1 mm are used as the substrates. A thin film transistor is formed over one of these substrates, and an insulating film and an alignment film are further formed over the surface of the thin film transistor. In this embodiment, rubbing treatment for aligning liquid crystal is performed using polyimide as an alignment film. An alignment film is similarly formed on the other substrate, and rubbing is performed. The rubbing directions on the upper and lower interfaces are almost parallel to each other, and the angle between the rubbing direction and the applied electric field direction is 75 degrees (Φ _LC1
= Φ _LC2 = 75 degrees). The dielectric anisotropy between these substrates is positive and its value is 12.0, and the refractive index anisotropy is 0.1.
A nematic liquid crystal composition of 079 (589 nm, 20 ° C.) is sealed. The cell gap d is obtained by dispersing and sandwiching spherical polymer beads between the substrates and enclosing the liquid crystal.
54 μm. Therefore, d _LC · Δn is 0.28 μm and d _eff · Δn is 0.24 μm. A pair of substrates is sandwiched between two polarizing plates, and the polarization axis of one of the polarizing plates is Φp ₁
= 75 degrees, and the other is Φp ₂ = -15 degrees.

FIG. 1 schematically shows a liquid crystal display device of the present invention. In the liquid crystal display panel, a light source 3 having a color temperature of 5885K having a light emission characteristic shown in FIG.
A liquid crystal display device is manufactured using an edge light type backlight unit composed of a light guide 32, a light guide 32, a diffusion plate 33, and a prism sheet 34.

When the liquid crystal display device is driven, the power consumption required for the light source unit is 1.8 W. FIG. 9A shows the spectral transmittance of the liquid crystal display panel when a driving voltage is applied. The spectrum when used is shown in FIG. These chromaticity coordinates are shown in FIG. The liquid crystal display panel is of a cold color type, and a good white balance can be obtained by combining this with a light source having a low color temperature.

The dielectric anisotropy between the substrates is positive and the value is 9.
0 and a refractive index anisotropy of 0.082 (589 nm, 2
(0 ° C.). The cell gap d is 3.8 μm. Therefore, d _LC · Δn is 0.3
1 μm and d _eff · Δn is 0.28 μm. A liquid crystal display device is manufactured using an edge-light type backlight unit using a cold-cathode tube fluorescent lamp having a color temperature of 11000 K and having a light emission characteristic shown in FIG. 8B as a light source.
FIG. 11A shows the spectral transmittance of the liquid crystal display panel when a driving voltage is applied, and FIG. 11B shows the spectrum when the light source is used. FIG. 12 shows these chromaticity coordinates. When a combination of a yellowish liquid crystal display panel and a cool color light source is used, the power consumption required for the light source unit is 2 W
It is.

The light source is replaced with an edge light type backlight unit having a color temperature of 5885K. At this time, the power consumption required for the light source unit is 1.8 W. FIG. 13A shows a spectrum when this light source is used, and FIG. 13B shows chromaticity coordinates. The liquid crystal display device can be visually recognized as having a yellow color.

As shown in FIG. 6, a color filter 24 is provided on a substrate opposed to a substrate having transistor elements. Between the substrates, the dielectric anisotropy is positive and the value is 7.3.
And a refractive index anisotropy of 0.074 (589 nm, 20
C) is enclosed. The cell gap d is set to 3.2 μm in a state where spherical polymer beads are dispersed and sandwiched between substrates and liquid crystal is sealed. Therefore,
d · Δn is 0.24 μm. FIG. 14A shows the spectral transmittance characteristics of the liquid crystal display element when a voltage is applied, and FIG. 14B shows the chromaticity coordinates of the liquid crystal display device including the light source. The chromaticity coordinates of the application of the driving voltage are almost located at the standard light source C. The power consumption required for the light source section is 1.8 W, and a horizontal electric field type liquid crystal display device with good color display can be obtained.

Between the substrates, the dielectric anisotropy is positive and the value is 9.0, and the refractive index anisotropy is 0.082 (589 nm, 20 nm).
C) is enclosed. The cell gap d is set to 3.7 μm in a state where spherical polymer beads are dispersed and sandwiched between substrates and liquid crystal is sealed. Therefore, d _LC · Δn is 0.30 μm, and d _eff · Δn is approximately 0.27 μm. It is made of polycarbonate and has a retardation of 595 n between the upper substrate and the polarizing plate.
m (550 nm), the slow axis angle Φ _F1 of the retardation film is parallel to the upper polarizer, that is, Φ _F1 = Φp ₁
= 75 degrees. This liquid crystal display panel has a color temperature 4348 having the light emission characteristics shown in FIG.
An edge light type backlight unit using a cold cathode fluorescent lamp of K is used as a light source. FIG. 15 shows a locus on the chromaticity coordinates when the voltage of the liquid crystal display device is turned on from off. The locus of the chromaticity coordinates approaches the C light source,
The power consumption required for the light source unit is 1.7W.

As shown in FIG. 6, on a substrate 7 opposed to a substrate having transistor elements, stripe-shaped R,
G, B, and three color filters 24 are provided. A protective film 25 for flattening the surface is laminated on the color filters, and the alignment film 5 is formed thereon. Made of polycarbonate between the substrate and the polarizing plate, with a retardation of 349n
m (550 nm), the slow axis angle Φ _F1 of the retardation film is orthogonal to the upper polarizer, that is, Φ _F1 = Φp ₂
= -15 degrees. This liquid crystal display panel has a color temperature of 470 having the light emission characteristics shown in FIG.
An edge light type backlight unit using a 3K cold cathode fluorescent lamp is used as a light source. The chromaticity coordinates of the liquid crystal display device when a driving voltage is applied are close to those of the C light source, and the power consumption required for the light source unit is 1.75 W.

The thickness of the color filter is approximately 2 μm for the B and G pixel portions, and approximately 2.5 μm for the R pixel portion. This difference remains as a step of about 0.3 μm even after the flattening film is applied by spin coating.
The difference is the thickness of the liquid crystal layer. In this liquid crystal display panel, an edge light type backlight unit using a cold cathode fluorescent lamp having a color temperature of 4703K is used as a light source. The wavelength of this liquid crystal display device is 615 nm, 545 nm, 465 nm.
FIG. 16 shows a voltage-transmittance characteristic in nm, that is, a voltage-transmittance characteristic corresponding to each of the R, G, and B pixels. It can be seen that the transmittance characteristics of the R pixel have shifted to the high voltage side. Accordingly, the transmittance of the liquid crystal display panel when a driving voltage is applied has a characteristic in which red is suppressed.
The white balance when driving voltage is applied is good, and the power consumption required for the light source unit is 1.75 W.

The film thickness of the color filter is approximately 2 μm for the G and R pixel portions, and approximately 1.5 μm for the B pixel portion. The thickness of the liquid crystal layer is approximately 3.8 μm for the G and R pixel portions, and approximately 4.1 μm for the B pixel portion. For this liquid crystal display element, an edge light type backlight unit using a cold cathode fluorescent lamp having a color temperature of 4703K is used as a light source. FIG. 17 shows voltage-transmittance characteristics of the liquid crystal display device at wavelengths of 615 nm, 545 nm, and 465 nm, that is, voltage-transmittance characteristics corresponding to R, G, and B pixels. It can be seen that the transmittance characteristics of the B pixel have shifted to the low voltage side. Therefore,
The transmittance of the liquid crystal display element when a driving voltage is applied has a characteristic in which blue is amplified. The white balance when the driving voltage was applied was good, and the power consumption required for the light source was 1.75 W.

The thickness of the color filter is approximately 2 μm for the G pixel portion, approximately 1.5 μm for the B pixel portion, and approximately 2.5 μm for the R pixel portion. The thickness of the liquid crystal layer is approximately 4.2 μm for the G pixel portion, approximately 3.9 μm for the R pixel portion, and approximately 3.9 μm for the B pixel portion. In this liquid crystal display panel, an edge light type backlight unit using a cold cathode fluorescent lamp with a color temperature of 4348K is used as a light source. The voltage of the liquid crystal display device at wavelengths of 615 nm, 545 nm, and 465 nm
FIG. 18 shows transmittance characteristics, that is, voltage-transmittance characteristics corresponding to R, G, and B pixels. It can be seen that the transmittance characteristics of the B pixel shift to the low voltage side, and the transmittance characteristics of the R pixel shift to the high voltage side. The white balance when the driving voltage is applied is good, and the power consumption required for the light source unit is 1.7 W.

The thickness of the color filter is approximately 2 μm for the G and R pixel portions, and approximately 1.5 μm for the B pixel portion. As for the thickness of the liquid crystal layer, the G and R pixel portions are approximately 4.5 μm, and the B pixel portion is approximately 4.2 μm. As the retardation film, a film made of polycarbonate and having a retardation of 997 nm (550 nm) is used between the upper substrate and the polarizing plate, and the angle Φ _F1 of the slow axis thereof is parallel to the upper polarizing plate, that is, Φ _F1 = Φp
Paste so that ₁ = 75 degrees. In this liquid crystal display panel, an edge light type backlight unit using a cold cathode fluorescent lamp with a color temperature of 4348K is used as a light source. FIG. 19 shows the locus on the chromaticity coordinates associated with the voltage application. It can be seen that the voltage approaches the C light source as the voltage is applied. The white balance when driving voltage is applied is good, and the power consumption required for the light source unit is 1.70 W.

[0032]

As described above, it is possible to provide a liquid crystal display device with low power consumption and good white balance.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a liquid crystal display device of the present invention.

FIG. 2 is a diagram showing a spectral transmittance characteristic of a liquid crystal display panel of a horizontal electric field type.

FIG. 3 is a diagram illustrating definitions of a rubbing direction and an axial direction of a polarizing plate.

FIG. 4 is a diagram showing an operation of a liquid crystal display device of an in-plane switching mode.

FIG. 5 is a diagram showing color temperature and chromaticity coordinates in UCS chromaticity coordinates.

FIG. 6 is a diagram illustrating a configuration of a color filter substrate.

FIG. 7 is a diagram showing light emission characteristics of a light source.

FIG. 8 is a diagram illustrating light emission characteristics of a light source.

FIG. 9 shows spectral transmittance characteristics of a liquid crystal display panel and spectral characteristics of a liquid crystal display device.

FIG. 10 shows chromaticity coordinates when a C light source, a light source, and a liquid crystal display device of a liquid crystal display panel are used.

FIG. 11 shows a spectral transmittance characteristic of a liquid crystal display panel and a spectral characteristic of a liquid crystal display device.

FIG. 12 illustrates a C light source of a liquid crystal display panel, a light source, and chromaticity coordinates of a liquid crystal display device.

FIG. 13 shows the spectral characteristics of the liquid crystal display panel, the C light source of the liquid crystal display panel, the light source, and the chromaticity coordinates of the liquid crystal display device.

FIG. 14 shows the spectral transmittance characteristics of the liquid crystal display panel, the C light source of the liquid crystal display panel, the light source, and the chromaticity coordinates of the liquid crystal display device.

FIG. 15 is a locus on a chromaticity diagram accompanying voltage application to the liquid crystal display device.

FIG. 16 is a diagram showing voltage-transmittance characteristics at three wavelengths of a liquid crystal display device.

FIG. 17 is a diagram showing voltage-transmittance characteristics at three wavelengths of a liquid crystal display device.

FIG. 18 is a diagram showing voltage-transmittance characteristics at three wavelengths of a liquid crystal display device.

FIG. 19 is a diagram showing a locus on a chromaticity diagram accompanying voltage application to the liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Common electrode, 2 ... Gate insulating film, 3 ... Signal electrode, 4 ...
Pixel electrode, 5 ... alignment film, 6 ... liquid crystal molecule, 7 ... substrate, 8 ...
Polarizing plate, 9 ... Electric field, 10 ... Rubbing direction, 11 ... Transmission axis of polarizing plate, 23 ... Active matrix type liquid crystal display element, 24 ... Color filter, 25 ... Protective film, 27 ... Insulating film, 30 ... Light source, 31 ... Light cover, 32 light guide,
33: diffusion plate, 34: prism sheet.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Ikuo Hiyama 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Osamu Ito 7-1, Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Inside Hitachi, Ltd.Hitachi Research Laboratories (72) Inventor Masato Oe 3300 Hayano, Mobara City, Chiba Prefecture Inside Electronic Device Division, Hitachi, Ltd. Hitachi, Ltd.Electronic Device Division (72) Inventor Keiichiro Ashizawa 3300 Hayano, Mobara City, Chiba Prefecture, Hitachi, Ltd.Electronic Device Division

Claims (7)

[Claims] A liquid crystal panel having a pair of substrates, a plurality of electrodes formed on at least one of the pair of substrates, and a liquid crystal layer sandwiched between the pair of substrates; A light source provided on a surface of the liquid crystal display device, wherein the light source has a light emission characteristic of warm color chromaticity, and the liquid crystal panel has a cool color chromaticity of spectral transmittance. A liquid crystal display device having characteristics and compensating for the color of the light source. 2. The liquid crystal display device according to claim 1, wherein the maximum value of the light transmission spectrum of the liquid crystal panel is 400.
A liquid crystal display device having a wavelength within a range of from 520 nm to 520 nm. 3. The liquid crystal display device according to claim 1, wherein a thickness (d _eff ) of a liquid crystal layer for changing an alignment direction when a voltage is applied to the liquid crystal panel, and a refractive index anisotropy (Δn) of the liquid crystal. _Wherein the product d _eff · Δn is 0.26 μm or less. 4. The liquid crystal display device according to claim 1, wherein a pair of polarizing plates are arranged in the liquid crystal panel so as to sandwich the pair of substrates, and a plurality of polarizing plates are arranged between the polarizing plates and the substrate. A liquid crystal display device comprising a refraction film. 5. The liquid crystal display device according to claim 1, wherein a color filter is provided on at least one of the pair of substrates, and the thickness of the liquid crystal layer at a portion that transmits red light transmits green light. A liquid crystal display device characterized in that the thickness is smaller than the thickness of the liquid crystal layer at the site. 6. The liquid crystal display device according to claim 1, wherein a color filter is provided on at least one of the pair of substrates, and the thickness of the liquid crystal layer at a portion that transmits blue light transmits green light. A liquid crystal display device characterized in that the thickness of the liquid crystal layer is thicker than the thickness of the liquid crystal layer. 7. The liquid crystal display device according to claim 1, wherein an electric field formed in the liquid crystal layer by the plurality of electrodes is:
A liquid crystal display device substantially parallel to the pair of substrates.