JP2014134559A - Liquid crystal dimming element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal dimming element having a high dichroic ratio in a short wavelength region at 490 nm or less.SOLUTION: A liquid crystal dimming element 10 includes a backlight 30, a liquid crystal layer 23 which controls a polarizing state of light from the backlight 30, and a pair of polarizing plates interposing the liquid crystal layer 23. The backlight 30 has at least one maximum in a wavelength range from 400 to 490 nm within an emission spectrum. The pair of polarizing plates comprises a first polarizing plate 21 and a second polarizing plate 25. The backlight 30, the first polarizing plate 21, the liquid crystal layer 23, and the second polarizing plate 25 are disposed successively in this order. The polarizing plate is composed of a uniaxial optical anisotropic film, and at least one of the polarizing plates has a wavelength region exhibiting 100 or more extinction ratio within ±25 nm range off the maximum of the backlight 30. When the maximum extinction ratio in the wavelength range from 400 to 490 nm and the maximum extinction ratio in the wavelength range from 380 to 780 nm are denoted by A and B, respectively, A and B satisfy A≥0.95B.

Description

 The present invention relates to a liquid crystal light control device.

 As one form of the liquid crystal light control device, a blue light emitting diode (LED) or a near ultraviolet light emitting diode (LED) is used as a backlight, and a phosphor is disposed in a portion corresponding to a color filter. . This phosphor-excited color conversion type liquid crystal light control device converts the wavelength of light emitted from a backlight with a phosphor and displays a desired color (RGB or the like). This liquid crystal light control device has the advantage of high light utilization efficiency because there is no loss due to light absorption and wavelength conversion is performed by a phosphor as compared with a color filter type.

 In the phosphor excitation color conversion type liquid crystal light control device, a polarizing plate is provided between the liquid crystal layer and the phosphor in order to selectively excite a desired phosphor (see, for example, Patent Document 1).

JP 2009-134275 A

However, when a blue or near-ultraviolet light source is used as the light source of the liquid crystal light control device, it is necessary to optimize the retardation value of the liquid crystal layer so that the transmittance is maximized in the corresponding wavelength region.
On the other hand, a polarizing plate using iodine, which is known as a general polarizing plate material, has a low dichroic ratio (contrast) because parallel transmittance decreases and orthogonal transmittance increases in a short wavelength region of 490 nm or less. There was a problem that it dropped.

 The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal light adjusting device having a high transmittance and dichroic ratio in a short wavelength region of 490 nm or less.

 The liquid crystal light control device of the present invention includes a light source, a liquid crystal device that controls a polarization state of light from the light source, and a pair of polarizing plates that sandwich the liquid crystal device, and the light source is within an emission spectrum. Having at least one maximum value in a wavelength range of 400 to 490 nm, and the pair of polarizing plates includes a first polarizing plate and a second polarizing plate, the light source, the first polarizing plate, the liquid crystal element, and the first polarizing plate. Two polarizing plates are provided in this order, and the polarizing plate is formed of a uniaxial optically anisotropic film, and at least one of the polarizing plates has an extinction ratio value of 100 or more in the range of the light source maximum value ± 25 nm. There is a wavelength region, and A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. .

 The liquid crystal light control device of the present invention includes a light source, a liquid crystal device that controls a polarization state of light from the light source, and a pair of polarizing plates provided on the liquid crystal device, and the light source is within an emission spectrum. The first polarizing plate is provided between the light source and the liquid crystal element, and the second polarizing plate is the liquid crystal in the wavelength range of 400 to 490 nm. Provided on the liquid crystal layer side of the substrate constituting the element, the polarizing plate is made of a uniaxial optical anisotropic film, and at least one of the polarizing plates has an extinction ratio value in the range of the maximum value ± 25 nm of the light source. There is a wavelength region indicating 100 or more, and A ≧ 0.95B where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. Features .

 The liquid crystal light control device of the present invention is a light source, a liquid crystal device that controls the polarization state of light from the light source, absorbs light transmitted through the liquid crystal device, and emits light in a wavelength region different from the wavelength region of the light source. And a pair of polarizing plates sandwiching the liquid crystal element, wherein the light source has at least one maximum value in a wavelength range of 400 to 490 nm in the emission spectrum, and the pair of polarizing plates , Comprising a first polarizing plate and a second polarizing plate, wherein the light source, the first polarizing plate, the liquid crystal element, the second polarizing plate and a phosphor are provided in this order, and the polarizing plate has uniaxial optical anisotropy It is made of a film, and at least one of the polarizing plates has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value of the light source ± 25 nm, and the maximum extinction ratio in the wavelength range of 400 to 490 nm is A , Wavelength 380-7 When the maximum value of the extinction ratio in the range of 0nm was B, and characterized in that the A ≧ 0.95B.

 The liquid crystal light control device of the present invention is a light source, a liquid crystal device that controls the polarization state of light from the light source, absorbs light transmitted through the liquid crystal device, and emits light in a wavelength region different from the wavelength region of the light source. And a pair of polarizing plates provided in the liquid crystal element, wherein the light source has at least one maximum value in a wavelength range of 400 to 490 nm in the emission spectrum, and the pair of polarized light Among the plates, the first polarizing plate is provided between the light source and the liquid crystal element, the second polarizing plate is provided on the liquid crystal layer side of the substrate constituting the liquid crystal element, and the polarizing plate is uniaxial optically anisotropic. And at least one of the polarizing plates has a wavelength region in which the extinction ratio value is 100 or more in the range of the light source maximum value ± 25 nm, and the maximum extinction ratio in the wavelength range of 400 to 490 nm. A, wavelength 380- When the maximum value of the extinction ratio in the range of 80nm is B, characterized in that the A ≧ 0.95B.

 The liquid crystal element preferably has an effective retardation value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the light source.

 The first polarizing plate and the second polarizing plate have an extinction ratio value of 100 or more in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the light source, and the wavelength range of 400 to 490 nm. When A is the maximum extinction ratio and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm, A ≧ 0.95B is exhibited, and at least one of the polarizing plates has a maximum wavelength of ± 25 nm of the light source. It is preferable to have the extinction ratio peak region in the range.

 The first polarizing plate and the second polarizing plate have an extinction ratio value of 100 or more in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the light source, and the wavelength range of 400 to 490 nm. Where A is the maximum value of the extinction ratio and B is the maximum value of the extinction ratio in the wavelength range of 380 to 780 nm, A ≧ 0.95B is shown, and the first polarizing plate and the second polarizing plate are the light source It is preferable to have a peak region of the extinction ratio in the range of the maximum wavelength of ± 25 nm.

It is preferable that the rate of change of the CR _z value obtained from the following formulas (1) to (3) with respect to the CR _y value obtained from the following formulas (4) to (6) is 5% or less.

(However, in formulas (1) to (6), T _p (λ) represents parallel transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a parallel Nicol arrangement). _c (λ) represents orthogonal transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a crossed Nicol arrangement), and Y (λ) represents a Y component of tristimulus values. (Λ) represents the Z component of tristimulus values.)

The liquid crystal light control device of the present invention is a light source, a liquid crystal device that controls the polarization state of light from the light source, and light that passes through the liquid crystal device is absorbed as excitation light and has a wavelength range different from the wavelength range of the light source. And a pair of polarizing plates sandwiching the liquid crystal element, and the light source has at least one maximum value in a wavelength range of 400 to 490 nm in an emission spectrum, and the polarizing plate Is characterized in that the parallel transmittance is 30% or more and the value of CR _z obtained from the following formulas (1) to (3) is 100 or more.

(However, in the formulas (1) to (3), T _p (λ) represents parallel transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a parallel Nicol arrangement). _c (λ) represents orthogonal transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a crossed Nicols arrangement). Z (λ) represents a Z component of tristimulus values.)

 According to the present invention, a liquid crystal light control device having a high transmittance and dichroic ratio in a short wavelength region of 490 nm or less can be obtained.

It is a schematic sectional drawing which shows the liquid crystal light control element of 1st Embodiment. Polarized light transmittance in the polarizing plate transmission axis direction and polarizing transmittance in the polarizing plate absorption axis direction of the polarizing film made of benzopurpurin which is one of the dichroic dyes provided on one surface of the iodine polarizing plate and the polyethylene terephthalate film It is a graph which shows. It is a schematic sectional drawing which shows the liquid-crystal light control element of 2nd Embodiment. It is a schematic sectional drawing which shows the liquid-crystal light control element of 3rd Embodiment. It is a schematic sectional drawing which shows the liquid crystal light control element of 4th Embodiment. It is a schematic sectional drawing which shows the liquid crystal light control element of 5th Embodiment. It is a schematic sectional drawing which shows the liquid crystal light control element of 6th Embodiment.

(1) 1st Embodiment FIG. 1: is a schematic sectional drawing which shows the liquid-crystal light control element of 1st Embodiment.
The liquid crystal light control device 10 of the present embodiment is schematically configured by a liquid crystal panel 20 and a backlight 30 disposed on the surface 20b side opposite to the display screen 20a.

The liquid crystal panel 20 includes a first polarizing plate 21, a first substrate 22, a liquid crystal layer 23 sandwiched between a pair of transparent electrodes (not shown), a second substrate 24, and a second polarizing plate 25. These have a structure in which they are stacked in order from the backlight 30 side.
The liquid crystal layer 23 is sandwiched between the first polarizing plate 21 and the second polarizing plate 25.
The first polarizing plate 21 is provided between the backlight 30 and the liquid crystal layer 23.
The second polarizing plate 25 is provided on the surface opposite to the surface in contact with the liquid crystal layer 23 of the second substrate 24.
The liquid crystal layer 23 includes a pixel electrode, a drive electrode, a thin film transistor (TFT), an alignment film, and the like, but illustration thereof is omitted here.

As the backlight 30, one having at least one maximum value in the wavelength range of 400 to 490 nm in the emission spectrum, that is, one having the maximum intensity in the wavelength range of 400 to 490 nm is used. What shows the maximum intensity | strength in the range of 470 nm is used.
As the backlight 30, for example, a blue light emitting diode (blue LED) having a maximum value near a wavelength of 455 nm, a blue fluorescent tube having maximum values at wavelengths of 430 nm and 490 nm, or the like is used.

At least one of the first polarizing plate 21 and the second polarizing plate 25 has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value ± 25 nm of the backlight 30, and in the wavelength range of 400 to 490 nm. When the maximum value of the extinction ratio is A and the maximum value of the extinction ratio in the wavelength range of 380 to 780 nm is B, the polarizing plate is a dichroic dye that satisfies the following formula (α).
A ≧ 0.95B (α)
Note that it is preferable that there is a wavelength region in which the extinction ratio value is 1000 or more in the range of the maximum value ± 25 nm of the backlight 30, and it is more preferable that there is a wavelength region in which the extinction ratio value is 10,000 or more.
In the above formula (α), the coefficient of B is 0.95, but preferably 0.97. If the coefficient of B is less than 0.95, the use efficiency of blue light is low, and display with low brightness and contrast is not preferable.

Here, the extinction ratio is expressed as performance inherent to each of the first polarizing plate 21 and the second polarizing plate 25 and is defined as follows.
Extinction ratio = (polarized light transmittance in the polarizing plate transmission axis direction) / (polarized light transmittance in the polarizing plate absorption axis direction)
Here, the polarization transmittance refers to the transmittance when ideal polarized light is incident using a Glan-Thompson prism.

 Examples of dichroic dyes include Acid red 266, Benzopurpurin, C.I. I. Examples include Direct Blue 67, Violet 20, Cyanine dye, Methyl Orange, Perylenebiscarboximides, RU 31.156, Sirius Supra Brown RLL, AH 6556, and the like.

FIG. 2 shows the polarizing transmittance in the polarizing plate transmission axis direction and polarizing plate absorption axis direction of a polarizing film made of benzopurpurin which is one of the dichroic dyes provided on one surface of the iodine polarizing plate and the polyethylene terephthalate film. It is a graph which shows the polarized light transmittance of this.
In FIG. 2, symbol a is the polarization transmittance in the polarizing plate transmission axis direction, symbol b is the polarization transmittance in the polarizing plate absorption axis direction, symbol c is the extinction ratio of the polarizing film, and symbol d is a blue light emitting diode (blue LED). The intensity of the light emitted from.

 As shown in FIG. 2, the polarizing film made of Benzopurpurin has a maximum extinction ratio near the wavelength of 430 to 470 nm, and this maximum extinction ratio is substantially equal to the maximum emission value of the blue LED indicated by the symbol d. Match. That is, the above formula (α) (A ≧ 0.95B) is satisfied.

As the 1st polarizing plate 21 and the 2nd polarizing plate 25, it is a uniaxial optical anisotropic film which consists of a coating-type polarizing film, a wire grid polarizing plate, etc., and the thing which does not require a support substrate is used.
As the uniaxial optical anisotropic film, a film having no restriction on the transmittance is used in the wavelength region other than the blue region. The uniaxial optically anisotropic film may be composed of a dichroic dye having almost no dichroic ratio (extinction ratio) in the light of the green to red region.

The uniaxial optically anisotropic film constituting the first polarizing plate 21 is prepared by dissolving a dichroic dye in various organic solvents to prepare a solution, and using a coating device such as a die coater, slit coater, bar coater, etc. It is formed by applying the solution on the surface opposite to the surface in contact with the liquid crystal layer 23 and drying it.
Similarly, the uniaxial optical anisotropic film forming the second polarizing plate 25 is prepared by dissolving a dichroic dye in various organic solvents to prepare a solution, and using a coating device such as a die coater, a slit coater, or a bar coater. The second substrate 24 is formed by applying the solution to the surface opposite to the surface in contact with the liquid crystal layer 23 and drying.
Examples of the method for orienting the dichroic dye include a method in which a solution in which the dichroic dye is dissolved is applied while applying a shearing force. According to this method, the direction in which the shearing force is applied, that is, the application direction of the solution becomes the transmission axis of the second polarizing plate 25, and the direction orthogonal to the direction in which the shearing force is applied is the absorption axis of the second polarizing plate 25. Become.

Further, as a method for aligning the dichroic dye, the surface of the second substrate 24 opposite to the surface in contact with the liquid crystal layer 23 is subjected to an alignment process such as rubbing, and the surface subjected to the alignment process is subjected to the alignment process. A method of orienting the dichroic dye by applying a solution in which the chromatic dye is dissolved is mentioned.
Furthermore, as a method for aligning the dichroic dye, an alignment film is formed on the surface of the second substrate 24 opposite to the surface in contact with the liquid crystal layer 23, and the alignment film is subjected to an alignment treatment such as rubbing. A method of orienting the dichroic dye by applying a solution in which the dichroic dye is dissolved is mentioned.
As described above, when the surface of the second substrate 24 opposite to the surface in contact with the liquid crystal layer 23 is subjected to the alignment treatment, and the solution in which the dichroic dye is dissolved is applied, the dichroic dye is aligned in the alignment treatment direction. Therefore, the absorption axis of the second polarizing plate 25 coincides with the alignment treatment direction.

 As a method for aligning the dichroic dye, a photo-alignment film is formed on the surface opposite to the surface in contact with the liquid crystal layer 23 of the second substrate 24, and ultraviolet or A method of orienting a dichroic dye by irradiating polarized ultraviolet rays is mentioned.

 Further, it is possible to adopt a structure in which the first polarizing plate 21 is installed on the surface side in contact with the liquid crystal layer 23 of the first substrate 22 by the same method as described above.

As the liquid crystal layer 23, it is preferable to use a liquid crystal layer having an effective retardation value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the backlight 30. In other words, the wavelength (WLC) at which the transmittance of the liquid crystal layer 23 is maximized and the wavelength (WBL) at which the backlight 30 exhibits the maximum intensity preferably satisfy the following relational expression (β). It is more preferable to satisfy the formula (γ).
WBL-25nm ≦ WLC ≦ WBL + 25nm (β)
WBL-25nm ≦ WLC ≦ WBL + 10nm (γ)

Here, the phase difference value at which the liquid crystal layer 23 exhibits the maximum transmittance will be described.
The retardation value at which the liquid crystal layer 23 exhibits the maximum transmittance means that the birefringence (Δn) and the cell thickness (d) of the liquid crystal layer 23 need to be appropriately designed according to each display mode. This is not the Δnd obtained by the product of the birefringence index (Δn) of 23 and the cell thickness (d), but the effective value of Δnd obtained when the liquid crystal layer 23 is driven.
For example, the following design is required for the phase difference value (Δnd).
As a liquid crystal material used for the VA mode, for example, when a material showing Δn = 0.1 at a wavelength (λ) of 550 nm is used, the phase difference for obtaining the maximum transmittance of the liquid crystal layer 23 is 270 nm. However, since the liquid crystal molecules in the vicinity of the alignment film interface do not respond to an electric field, if the cell thickness (d) is simply set to 2.7 μm, the Δnd value is insufficient, so the cell thickness (d) is set to about 3.2 μm. It is common.

 In the VA liquid crystal layer, the voltage-transmittance curve (VT curve) or gradation-luminance characteristic (gamma curve) of each pixel of RGB is different for each color. This is because the refractive index of the liquid crystal molecules has wavelength dispersion. In order to match the RGB gamma characteristics, there is a case where no voltage is applied until the liquid crystal molecules are completely tilted. That is, the liquid crystal layer does not use the retardation value indicating the maximum transmittance, sets the maximum transmittance for each color in consideration of the RGB balance, and sets the effective Δnd value.

An example in which the liquid crystal material used in the VA mode in this embodiment is used is shown below.
In the liquid crystal layer 23, Δn increases at a wavelength (λ) of 455 nm and becomes approximately Δn = 0.11. Therefore, the cell thickness that satisfies the condition that the effective phase difference satisfies λ / 2 is VA mode liquid crystal. It is about 10% thinner than the layer.
Therefore, the cell thickness of 2.9 μm, which is about 10% thinner than the cell thickness of 3.2 μm designed for the wavelength of 550 nm, can be designed as the optimum value.
In this embodiment, Δnd needs to be taken into consideration only for the blue region. Therefore, it is possible to obtain the maximum transmittance by applying a voltage until the response of the liquid crystal molecules is saturated, thereby improving the light utilization efficiency. be able to.
On the other hand, setting the maximum transmittance at a voltage at which the response of the liquid crystal molecules does not saturate has the effect of increasing the response speed, and thus such a design is possible.

Also in the IPS mode, it is possible to appropriately design the effective Δnd in consideration of the fact that the liquid crystal molecules in the vicinity of the alignment film cannot be driven by an electric field and that the refractive index of the liquid crystal layer has wavelength dispersion. .
Similarly, a design that prioritizes transmittance or a design that prioritizes response speed is possible.

 Further, similarly in the TN mode, the effective phase difference (Δn) and the optimum value of the cell thickness of the liquid crystal layer at the backlight main wavelength can be obtained, and the effective Δnd can be appropriately designed.

In the liquid crystal light control device 10, the value of a contrast obtained from the following formula in the value of a contrast obtained from equation (1) to the following _{(3) (CR z) (} 4) ~ (6) (CR y) It is preferable that the change rate with respect to is 5% or less.

However, in the formulas (1) to (6), T _p (λ) represents parallel transmittance (spectral transmittance measured by installing the first polarizing plate 21 and the second polarizing plate 25 in parallel Nicol arrangement). T _c (λ) represents the orthogonal transmittance (spectral transmittance measured by placing the first polarizing plate 21 and the second polarizing plate 25 in a crossed Nicol arrangement). Y (λ) represents the Y component of the tristimulus value. Z (λ) represents a Z component of tristimulus values.

 Thus, in the present embodiment, the contrast is defined as a value measured in the combination of the first polarizing plate 21 and the second polarizing plate 25.

Conventionally, the iodine polarizing plate that has been used has a characteristic that the transmittance is significantly reduced in a blue region, particularly in a region of a wavelength of 490 nm or less. Further, it is known that the light leakage when the first polarizing plate 21 and the second polarizing plate 25 are installed in a crossed Nicol arrangement becomes large in a wavelength region of 490 nm or less and the contrast is lowered. The maximum extinction ratio (or contrast) of the iodine polarizing plate appears in the vicinity of 600 to 650 nm.
In designing a liquid crystal light control device, the contrast and transmittance are generally optimally designed mainly in the region of 550 nm. Therefore, the contrast (CR _y ) obtained from the above equations (4) to (6). The value of was the most important.

Actually, when the contrast (CR _z ) value of the iodine polarizing plate is compared with the contrast (CR _y ) value, the contrast (CR _z ) value decreases by 10% or more compared to the contrast (CR _y ) value. I found out.
On the other hand, the first polarizing plate 21 and the second polarizing plate 25 in the present embodiment have increased transmittance in the blue region, and the extinction ratio (contrast) value has the maximum value in the blue region. The change rate of the contrast (CR _z ) value with respect to the _y ) value is as small as 1% or less, and the liquid crystal light control device 10 exhibits high contrast even in the blue region.

 According to the liquid crystal light control device 10, the first polarizing plate 21 provided between the backlight 30 and the liquid crystal layer 23 and the surface of the second substrate 24 opposite to the surface in contact with the liquid crystal layer 23 are provided. And a second polarizing plate 25, and at least one of the first polarizing plate 21 and the second polarizing plate 25 has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value ± 25 nm of the backlight 30. From the uniaxial optical anisotropic film in which A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. Therefore, in a short wavelength region of a wavelength of 490 nm or less, the transmittance can be increased and a high contrast can be achieved. Further, since the liquid crystal layer 23 has an effective phase difference value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the backlight 30, the light in the liquid crystal light control device 10. In addition, the process margin can be increased, such as a reduction in transmittance due to a change in cell thickness.

(2) Second Embodiment FIG. 3 is a schematic cross-sectional view showing a liquid crystal light control device of a second embodiment.
The liquid crystal dimming element 40 of this embodiment is schematically configured by a liquid crystal panel 50 and a backlight 60 disposed on the surface 50b side opposite to the display screen 50a.

The liquid crystal panel 50 includes a first polarizing plate 51, a first substrate 52, a liquid crystal layer 53 sandwiched between a pair of transparent electrodes (not shown), a protective film 54, a second polarizing plate 55, and a second substrate. 56, and these are laminated in order from the backlight 60 side.
The liquid crystal layer 53 is sandwiched between the first polarizing plate 51 and the second polarizing plate 55.
The first polarizing plate 51 is provided between the backlight 60 and the liquid crystal layer 53.
The second polarizing plate 55 is provided on the side of the second substrate 56 facing the liquid crystal layer 53.
A protective film 54 is provided between the liquid crystal layer 53 and the second polarizing plate 55.
Note that the liquid crystal layer 53 includes a pixel electrode, a drive electrode, a thin film transistor (TFT), an alignment film, and the like, but illustration thereof is omitted here.

As the 1st polarizing plate 51, the thing similar to the above-mentioned 1st Embodiment is used.
As the 2nd polarizing plate 55, the thing similar to the above-mentioned 1st Embodiment is used.
As the liquid crystal layer 53, the same liquid crystal layer as that in the first embodiment is used.
As the backlight 60, the thing similar to the above-mentioned 1st Embodiment is used.

 According to the liquid crystal light adjusting device 40, the first polarizing plate 51 provided between the backlight 60 and the liquid crystal layer 53, and the second polarizing plate provided on the side of the second substrate 56 facing the liquid crystal layer 53. 55, and at least one of the first polarizing plate 51 and the second polarizing plate 55 has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value ± 25 nm of the backlight 60, and the wavelength Since the maximum value of the extinction ratio in the range of 400 to 490 nm is A and the maximum value of the extinction ratio in the range of wavelengths 380 to 780 nm is B, it is composed of a uniaxial optical anisotropic film with A ≧ 0.95B. In a short wavelength region of 490 nm or less, the transmittance can be increased and a high contrast can be achieved. Further, since the liquid crystal layer 53 has an effective phase difference value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the backlight 60, the light in the liquid crystal light control device 40. In addition, the process margin can be increased, such as a reduction in transmittance due to a change in cell thickness.

(3) Third Embodiment FIG. 4 is a schematic cross-sectional view showing a liquid crystal light control device of a third embodiment.
The liquid crystal light adjusting device 70 of the present embodiment is schematically configured from a liquid crystal panel 80 and a backlight 90 disposed on the surface 80b side opposite to the display screen 80a.

The liquid crystal panel 80 includes a first substrate 81, a first polarizing plate 82, a first protective film 83, a liquid crystal layer 84 sandwiched between a pair of transparent electrodes (not shown), a second protective film 85, 2 polarizing plate 86 and the 2nd board | substrate 87 are comprised, and these have comprised the structure laminated | stacked in order from the backlight 90 side.
The liquid crystal layer 84 is sandwiched between the first polarizing plate 82 and the second polarizing plate 86.
The first polarizing plate 82 is provided on the side of the first substrate 81 that faces the liquid crystal layer 84.
The second polarizing plate 86 is provided on the side of the second substrate 87 facing the liquid crystal layer 84.
A first protective film 83 is provided between the liquid crystal layer 84 and the first polarizing plate 82.
A second protective film 85 is provided between the liquid crystal layer 84 and the second polarizing plate 86.
Note that the liquid crystal layer 84 includes a pixel electrode, a drive electrode, a thin film transistor (TFT), an alignment film, and the like, but illustration thereof is omitted here.

As the 1st polarizing plate 82, the thing similar to the above-mentioned 1st Embodiment is used.
As the 2nd polarizing plate 86, the thing similar to the above-mentioned 1st Embodiment is used.
As the liquid crystal layer 84, the same liquid crystal layer as that in the first embodiment is used.
As the backlight 90, the thing similar to the above-mentioned 1st Embodiment is used.

 According to the liquid crystal light adjusting device 70, the first polarizing plate 82 provided on the surface side facing the liquid crystal layer 84 of the first substrate 81 and the surface side facing the liquid crystal layer 84 of the second substrate 87 are provided. A second polarizing plate 86, and at least one of the first polarizing plate 82 and the second polarizing plate 86 has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value ± 25 nm of the backlight 90. From the uniaxial optical anisotropic film in which A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. Therefore, in a short wavelength region of a wavelength of 490 nm or less, the transmittance can be increased and a high contrast can be achieved. Further, since the liquid crystal layer 84 has an effective retardation value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the backlight 90, the light in the liquid crystal light control device 70 is obtained. In addition, the process margin can be increased, such as a reduction in transmittance due to a change in cell thickness.

(4) Fourth Embodiment FIG. 5 is a schematic cross-sectional view showing a liquid crystal light control device of a fourth embodiment.
The liquid crystal light control device 100 of the present embodiment is schematically configured by a liquid crystal panel 110 and a backlight 120 disposed on the surface 110b side opposite to the display screen 110a.

The liquid crystal panel 110 includes a first polarizing plate 111, a first substrate 112, a liquid crystal layer 113 sandwiched between a pair of transparent electrodes (not shown), a second substrate 114, a second polarizing plate 115, a band pass. The filter 116, the phosphor layer 117, the third substrate 118, and the external light filter 119 are provided, and have a structure in which these are sequentially stacked from the backlight 120 side.
The liquid crystal layer 113 is sandwiched between the first polarizing plate 111 and the second polarizing plate 115.
The first polarizing plate 111 is provided between the backlight 120 and the liquid crystal layer 113.
The second polarizing plate 115 is provided on the surface opposite to the surface facing the liquid crystal layer 113 of the second substrate 114.
Note that the liquid crystal layer 113 includes a pixel electrode, a drive electrode, a thin film transistor (TFT), an alignment film, and the like, but illustration thereof is omitted here.

As the 1st polarizing plate 111, the thing similar to the above-mentioned 1st Embodiment is used.
As the 2nd polarizing plate 115, the thing similar to the above-mentioned 1st Embodiment is used.
As the liquid crystal layer 113, the same liquid crystal layer as that in the first embodiment is used.

As the backlight 120, the thing similar to the above-mentioned 1st Embodiment is used.
A linear film called a louver arranged in a blind shape may be arranged between the liquid crystal panel 110 and the backlight 120. The linear film collimates the light emitted from the backlight 120 and irradiates the liquid crystal panel 110 with the collimated light (parallel light). Alternatively, the light emitted from the backlight 120 is substantially collimated by the linear film, and the liquid crystal panel 110 is irradiated with the substantially collimated light (substantially parallel light).
As described above, a linear film arranged in a blind shape called a louver may be arranged between the liquid crystal panel 110 and the backlight 120 for the purpose of enhancing directivity. It is not limited to this.

 The band-pass filter 116 has a structure such as a dielectric multilayer film, and the thickness of the band-pass filter 116 is set until the light transmitted through the second polarizing plate 115 enters the phosphor layer 117. It is preferable to set the degree of optical crosstalk that excites the phosphor placed in the adjacent pixel region. Specifically, the thickness of the band pass filter 116 is preferably smaller than the pixel interval.

 The phosphor layer 117 includes a scatterer layer 117B, a red phosphor layer 117R, and a green phosphor layer 117G.

 As the external light filter 119, a band-pass filter that transmits light in the visible light region and absorbs or reflects light in the blue to near ultraviolet region is used.

 According to the liquid crystal light control device 100, the first polarizing plate 111 provided between the backlight 120 and the liquid crystal layer 113 and the surface opposite to the surface facing the liquid crystal layer 113 of the second substrate 114 are provided. The second polarizing plate 115, and at least one of the first polarizing plate 111 and the second polarizing plate 115 has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value ± 25 nm of the backlight 120. A uniaxial optical anisotropic film in which A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm Therefore, the transmittance can be increased and a high contrast can be achieved in a short wavelength region of a wavelength of 490 nm or less. Further, since the liquid crystal layer 113 has an effective phase difference value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the backlight 120, the light in the liquid crystal light control device 100. In addition, the process margin can be increased, such as a reduction in transmittance due to a change in cell thickness.

 In this embodiment, the phosphor layer 117 is exemplified by the three primary colors composed of the scatterer layer 117B, the red phosphor layer 117R, and the green phosphor layer 117G. However, the present invention is not limited thereto. It is not limited. In the present invention, the phosphor layer may be of four primary colors or five primary colors, and a phosphor layer having a desired emission spectrum can be used.

(5) Fifth Embodiment FIG. 6 is a schematic cross-sectional view showing a liquid crystal light control device of a fifth embodiment.
The liquid crystal dimming element 130 of this embodiment is schematically configured by a liquid crystal panel 140 and a backlight 150 disposed on the surface 140b side opposite to the display screen 140a.

The liquid crystal panel 140 includes a first polarizing plate 141, a first substrate 142, a liquid crystal layer 143 sandwiched between a pair of transparent electrodes (not shown), a protective film 144, a second polarizing plate 145, and a bandpass filter. 146, the phosphor layer 147, the second substrate 148, and the external light filter 149, which are stacked in order from the backlight 150 side.
The liquid crystal layer 143 is sandwiched between the first polarizing plate 141 and the second polarizing plate 145.
The first polarizing plate 141 is provided between the backlight 150 and the liquid crystal layer 143.
The second polarizing plate 145 is provided on the side of the second substrate 148 facing the liquid crystal layer 143.
A protective film 144 is provided between the liquid crystal layer 143 and the second polarizing plate 145.
Note that the liquid crystal layer 143 includes a pixel electrode, a drive electrode, a thin film transistor (TFT), an alignment film, and the like, but illustration thereof is omitted here.

As the 1st polarizing plate 141, the thing similar to the above-mentioned 1st Embodiment is used.
As the 2nd polarizing plate 145, the thing similar to the above-mentioned 1st Embodiment is used.
As the liquid crystal layer 143, the same liquid crystal layer as that in the first embodiment is used.

As the backlight 150, the thing similar to the above-mentioned 1st Embodiment is used.
Further, a linear film arranged in a blind shape called a louver may be disposed between the liquid crystal panel 140 and the backlight 150 as in the above-described fourth embodiment.
In addition, a linear film called a louver arranged in a blind shape may be arranged between the liquid crystal panel 140 and the backlight 150 for the purpose of improving directivity. It is not limited.

 As the band-pass filter 146, the same filter as in the above-described fourth embodiment is used.

 The phosphor layer 147 includes a scatterer layer 147B, a red phosphor layer 147R, and a green phosphor layer 147G.

 As the external light filter 149, the same filter as in the above-described fourth embodiment is used.

 According to the liquid crystal light adjusting device 130, the first polarizing plate 141 provided between the backlight 150 and the liquid crystal layer 143 and the second polarizing plate provided on the surface facing the liquid crystal layer 143 of the second substrate 148. 145, and at least one of the first polarizing plate 141 and the second polarizing plate 145 has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value ± 25 nm of the backlight 150, and the wavelength Since the maximum value of the extinction ratio in the range of 400 to 490 nm is A and the maximum value of the extinction ratio in the range of wavelengths 380 to 780 nm is B, it is composed of a uniaxial optical anisotropic film with A ≧ 0.95B. In a short wavelength region of 490 nm or less, the transmittance can be increased and a high contrast can be achieved. Further, since the liquid crystal layer 143 has an effective retardation value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the backlight 150, the light in the liquid crystal light control device 100 In addition, the process margin can be increased, such as a reduction in transmittance due to a change in cell thickness.

(6) Sixth Embodiment FIG. 7 is a schematic cross-sectional view showing a liquid crystal light control device of a sixth embodiment.
The liquid crystal dimming element 160 of this embodiment is schematically configured by a liquid crystal panel 170 and a backlight 190 disposed on the surface 170b side opposite to the display screen 170a.

The liquid crystal panel 170 includes a first substrate 171, a first polarizing plate 172, a first protective film 173, a liquid crystal layer 174 sandwiched between a pair of transparent electrodes (not shown), a second protective film 175, 2 polarizing plate 176, band pass filter 177, phosphor layer 178, second substrate 179, and external light filter 180, which are stacked in order from the backlight 190 side. Yes.
The liquid crystal layer 174 is sandwiched between the first polarizing plate 172 and the second polarizing plate 176.
The first polarizing plate 172 is provided on the side of the first substrate 171 facing the liquid crystal layer 174.
The second polarizing plate 176 is provided on the surface of the second substrate 179 that faces the liquid crystal layer 174.
A first protective film 173 is provided between the liquid crystal layer 174 and the first polarizing plate 172.
A second protective film 175 is provided between the liquid crystal layer 174 and the second polarizing plate 176.
Note that the liquid crystal layer 174 includes a pixel electrode, a drive electrode, a thin film transistor (TFT), an alignment film, and the like, but illustration thereof is omitted here.

As the 1st polarizing plate 172, the thing similar to the above-mentioned 1st Embodiment is used.
As the 2nd polarizing plate 176, the thing similar to the above-mentioned 1st Embodiment is used.
As the liquid crystal layer 174, the same liquid crystal layer as that in the first embodiment is used.

As the backlight 190, the thing similar to the above-mentioned 1st Embodiment is used.
Further, a linear film arranged in a blind shape called a louver may be disposed between the liquid crystal panel 170 and the backlight 190 as in the fourth embodiment described above.
A linear film called a louver may be arranged between the liquid crystal panel 170 and the backlight 190 for the purpose of improving directivity. It is not limited.

 As the band pass filter 177, the same one as in the fourth embodiment described above is used.

 The phosphor layer 178 includes a scatterer layer 178B, a red phosphor layer 178R, and a green phosphor layer 178G.

 As the external light filter 180, the thing similar to the above-mentioned 4th Embodiment is used.

 According to the liquid crystal light control device 160, the first polarizing plate 172 provided on the surface facing the liquid crystal layer 174 of the first substrate 171 and the surface facing the liquid crystal layer 174 of the second substrate 179 are provided. A second polarizing plate 176, and at least one of the first polarizing plate 172 and the second polarizing plate 176 has a wavelength region in which the extinction ratio value is 100 or more in the range of the maximum value ± 25 nm of the backlight 190. From the uniaxial optical anisotropic film in which A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. Therefore, in a short wavelength region of a wavelength of 490 nm or less, the transmittance can be increased and a high contrast can be achieved. Further, since the liquid crystal layer 174 has an effective retardation value that maximizes the transmittance in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the backlight 190, the light in the liquid crystal light control device 160 In addition, the process margin can be increased, such as a reduction in transmittance due to a change in cell thickness.

 The present invention can be used in the field of liquid crystal light control devices.

10, 40, 70, 100, 130, 160... Liquid crystal light control elements 20, 50, 80, 110, 140, 170... Liquid crystal panels 21, 51, 82, 111, 141, 172. Polarizing plates 22, 52, 81, 112, 142, 171 ... first substrates 23, 53, 84, 113, 143, 174 ... liquid crystal layers 24, 56, 87, 114, 148, 179 ... first Two substrates 25, 55, 86, 115, 145, 176 ... second polarizing plates 30, 60, 90, 120, 150, 190 ... backlights 54, 144, ... protective films 83, 173, ... First protective film 85, 175, second protective film 116, 146, 177, band pass filter 117, 147, 178, phosphor layer 118, third substrate 119, 149, 180 ..External light fill

Claims (9)

A light source, a liquid crystal element that controls a polarization state of light from the light source, and a pair of polarizing plates that sandwich the liquid crystal element,
The light source has at least one maximum value in a wavelength range of 400 to 490 nm in the emission spectrum;
The pair of polarizing plates includes a first polarizing plate and a second polarizing plate,
The light source, the first polarizing plate, the liquid crystal element and the second polarizing plate are provided in this order,
The polarizing plate is composed of a uniaxial optically anisotropic film,
At least one of the polarizing plates has a wavelength region in which the extinction ratio value is 100 or more in the range of the light source maximum value ± 25 nm,
A liquid crystal light control device, wherein A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. A light source, a liquid crystal element that controls a polarization state of light from the light source, and a pair of polarizing plates provided in the liquid crystal element,
The light source has at least one maximum value in a wavelength range of 400 to 490 nm in the emission spectrum;
Of the pair of polarizing plates, the first polarizing plate is provided between the light source and the liquid crystal element, and the second polarizing plate is provided on the liquid crystal layer side of the substrate constituting the liquid crystal element,
The polarizing plate is composed of a uniaxial optically anisotropic film,
At least one of the polarizing plates has a wavelength region in which the extinction ratio value is 100 or more in the range of the light source maximum value ± 25 nm,
A liquid crystal light control device, wherein A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. A light source, a liquid crystal element that controls a polarization state of light from the light source, a phosphor that absorbs light transmitted through the liquid crystal element and emits light in a wavelength range different from the wavelength range of the light source, and the liquid crystal element A pair of polarizing plates sandwiched between,
The light source has at least one maximum value in a wavelength range of 400 to 490 nm in the emission spectrum;
The pair of polarizing plates includes a first polarizing plate and a second polarizing plate,
The light source, the first polarizing plate, the liquid crystal element, the second polarizing plate and a phosphor are provided in this order,
The polarizing plate is composed of a uniaxial optically anisotropic film,
At least one of the polarizing plates has a wavelength region in which the extinction ratio value is 100 or more in the range of the light source maximum value ± 25 nm,
A liquid crystal light control device, wherein A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm. A light source, a liquid crystal element that controls a polarization state of light from the light source, a phosphor that absorbs light transmitted through the liquid crystal element and emits light in a wavelength range different from the wavelength range of the light source, and the liquid crystal element A pair of polarizing plates provided,
The light source has at least one maximum value in a wavelength range of 400 to 490 nm in the emission spectrum;
Of the pair of polarizing plates, the first polarizing plate is provided between the light source and the liquid crystal element, and the second polarizing plate is provided on the liquid crystal layer side of the substrate constituting the liquid crystal element,
The polarizing plate is composed of a uniaxial optically anisotropic film,
At least one of the polarizing plates has a wavelength region in which the extinction ratio value is 100 or more in the range of the light source maximum value ± 25 nm,
A liquid crystal light control device, wherein A ≧ 0.95B, where A is the maximum extinction ratio in the wavelength range of 400 to 490 nm and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm.  5. The liquid crystal device according to claim 1, wherein the liquid crystal element has an effective retardation value that maximizes transmittance in a range of a maximum wavelength of ± 25 nm existing in a wavelength range of 400 to 490 nm of the light source. 2. A liquid crystal light control device according to item 1. The first polarizing plate and the second polarizing plate have an extinction ratio value of 100 or more in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the light source, and the wavelength range of 400 to 490 nm. When A is the maximum extinction ratio in A and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm, A ≧ 0.95B,
6. The liquid crystal light adjusting device according to claim 1, wherein at least one of the polarizing plates has a peak region of an extinction ratio in a range of a maximum wavelength of ± 25 nm of the light source. The first polarizing plate and the second polarizing plate have an extinction ratio value of 100 or more in the range of the maximum wavelength ± 25 nm existing in the wavelength range of 400 to 490 nm of the light source, and the wavelength range of 400 to 490 nm. When A is the maximum extinction ratio in A and B is the maximum extinction ratio in the wavelength range of 380 to 780 nm, A ≧ 0.95B,
The liquid crystal adjustment according to claim 1, wherein the first polarizing plate and the second polarizing plate have a peak region of an extinction ratio in a range of a maximum wavelength of ± 25 nm of the light source. Optical element. The rate of change of the CR _z value obtained from the following equations (1) to (3) with respect to the CR _y value obtained from the following equations (4) to (6) is 5% or less. Item 8. The liquid crystal light adjusting device according to any one of Items 1 to 7.

(However, in formulas (1) to (6), T _p (λ) represents parallel transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a parallel Nicol arrangement). _c (λ) represents orthogonal transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a crossed Nicol arrangement), and Y (λ) represents a Y component of tristimulus values. (Λ) represents the Z component of tristimulus values.) A light source, a liquid crystal element that controls a polarization state of light from the light source, a phosphor that absorbs light transmitted through the liquid crystal element as excitation light, and generates light in a wavelength range different from the wavelength range of the light source, A pair of polarizing plates sandwiching the liquid crystal element,
The light source has at least one maximum value in a wavelength range of 400 to 490 nm in the emission spectrum;
The polarizing plate, liquid crystal light control device in which the value of CR _z that parallel transmittance is determined from the 30% or more and the following formula (1) to (3), characterized in that 100 or more.

(However, in the formulas (1) to (3), T _p (λ) represents parallel transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a parallel Nicol arrangement). _c (λ) represents orthogonal transmittance (spectral transmittance measured by placing the first polarizing plate and the second polarizing plate in a crossed Nicols arrangement). Z (λ) represents a Z component of tristimulus values.)

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