JP6213075B2 - Method for evaluating liquid crystal and method for evaluating liquid crystal panel - Google Patents

Description

  The present invention relates to a liquid crystal evaluation method and a liquid crystal panel evaluation method, and specifically relates to a method for analyzing and evaluating three-dimensional movement, diffusion state, alignment state, and the like of liquid crystal molecules by single molecule emission analysis. .

  In recent years, by adding a trace amount of a fluorescent substance to an evaluation sample such as a polymer or a biopolymer, and irradiating excitation light, the fluorescent substance that is excited by the excitation light and emits fluorescence is traced. Observation of a diffusion process or the like is performed (see Non-Patent Document 1). In this method, since the movement, diffusion state, etc. of the substance in the evaluation sample at the molecular level can be analyzed, knowledge that has not been obtained so far can be obtained.

  Incidentally, in recent years, flat panel displays (FPD) such as liquid crystal panels are widely used worldwide. For this reason, the request | requirement of the characteristic improvement with respect to a liquid crystal panel is only increasing.

  In a liquid crystal panel, various evaluation methods are used in order to ensure necessary characteristics and reliability of a liquid crystal layer disposed between substrates. Specifically, an electrical evaluation method for measuring and evaluating ion density, current value, specific resistance value, etc., or an optical evaluation method for measuring and evaluating a liquid crystal panel with a polarizing microscope, a CCD camera, etc. Is known (see Patent Documents 1 to 4).

  However, none of these evaluation methods is a technique for macroscopically evaluating the characteristics of a liquid crystal panel and measuring and evaluating the movement, diffusion state, alignment state, etc. of liquid crystal molecules at the molecular level. .

Japanese Patent No. 3224027 Japanese Patent No. 3899874 Japanese Patent No. 4427372 Japanese Patent No. 4515535

ACS MacroLett. 1 (2012) 784-788.

  The present invention has been proposed in view of such conventional circumstances, and has not been obtained so far by analyzing the movement, diffusion state, orientation state, and the like of liquid crystal molecules in a liquid crystal sample at the molecular level. An object of the present invention is to provide a liquid crystal evaluation method and a liquid crystal panel evaluation method capable of evaluating characteristics of liquid crystals and liquid crystal panels.

In order to achieve the above object, the present invention provides the following means.
[1] preparing a liquid crystal sample containing a luminescent substance;
Measuring three-dimensional spatial coordinates (x, y, z) of a luminescent substance that emits light when excited in the liquid crystal sample while irradiating the liquid crystal sample with excitation light;
Evaluating the movement of the liquid crystal molecules contained in the liquid crystal sample in the x-, y-, and z-axis directions based on the measurement result of the luminescent substance.

[2] The method for evaluating a liquid crystal according to [1], wherein the luminescent substance is diffused in the liquid crystal sample.

[3] The method for evaluating a liquid crystal according to the above [2], wherein the content of the luminescent substance contained in the liquid crystal sample is 10 ⁻⁸ mol / L or less.

[4] A three-dimensional space of the luminescent material is obtained by acquiring an image of a luminescent material that emits light having a wavelength different from that of the excitation light in the liquid crystal sample while irradiating the liquid crystal sample with excitation light. Coordinates (x, y, z) are measured, The evaluation method of the liquid crystal as described in any one of said [1]-[3] characterized by the above-mentioned.

[5] The method for evaluating a liquid crystal according to any one of [1] to [4], wherein three-dimensional spatial coordinates (x, y, z) of the luminescent substance are simultaneously measured. .

[6] The method for evaluating a liquid crystal according to any one of [1] to [5], wherein the luminescent substance is measured in a time-sharing manner.

[7] The method for evaluating a liquid crystal according to [6], wherein a diffusion coefficient of the liquid crystal molecules is obtained from a moving distance per unit time of the luminescent substance.

[8] The method for evaluating a liquid crystal according to [7], wherein a diffusion coefficient of the liquid crystal molecules in at least two axial directions in the liquid crystal sample is obtained.

[9] the diffusion coefficient in the x-axis direction of liquid crystal molecules included in the liquid crystal sample and D _x, the diffusion coefficient in the y-axis direction and D _y, the diffusion coefficient in the z-axis direction is taken as D _z, respectively The liquid crystal evaluation method according to [7] or [8], wherein the diffusion coefficients D _x , D _y , and D _z are calculated by any one of the following formulas (1) to (3).
2D _x Δt = <{x (t + Δt) −x (t)} ² > (1)
2D _y Δt = <{y (t + Δt) −y (t)} ² > (2)
2D _z Δt = <{z (t + Δt) −z (t)} ² > (3)
(In the above formulas (1) to (3), x (t), y (t), and z (t) are the x-coordinate and y-coordinate of the center position of the luminescent point of the luminescent material at t seconds Z (t + Δt), y (t + Δt), and z (t + Δt) represent the x, y, and z coordinates of the center position of the luminescent point of the luminescent material at t + Δt seconds, respectively.

[10] The method for evaluating a liquid crystal according to any one of [1] to [9], wherein the movement or alignment state of the liquid crystal molecules is analyzed based on a measurement result of the luminescent substance. .

[11] The liquid crystal evaluation method according to any one of [1] to [10], wherein the measurement is performed in a state where the liquid crystal sample is sandwiched between substrates.

[12] A method for evaluating a liquid crystal panel in which a liquid crystal layer is disposed between substrates,
Preparing a liquid crystal panel to which a luminescent material is added in the liquid crystal layer;
Measuring the three-dimensional spatial coordinates (x, y, z) of a luminescent substance that emits light when excited in the liquid crystal layer while irradiating the liquid crystal panel with excitation light;
Evaluating the liquid crystal panel based on the measurement result of the luminescent substance, and a liquid crystal panel evaluation method.

[13] The liquid crystal panel according to [12], wherein measurement is performed with an electric field applied to the liquid crystal layer and measurement is performed without applying an electric field to the liquid crystal layer. Evaluation method.

  As described above, according to the present invention, the movement, diffusion state, alignment state, and the like of liquid crystal molecules in a liquid crystal sample are analyzed at the molecular level, and characteristics of liquid crystals and liquid crystal panels that have not been obtained so far are evaluated. It is possible to provide a liquid crystal evaluation method and a liquid crystal panel evaluation method that enable this.

It is a flowchart which shows the procedure of the evaluation method of the liquid crystal which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the measuring device used by this embodiment. It is a flowchart which shows the procedure of the evaluation method of the liquid crystal panel which concerns on embodiment of this invention. (A) is a schematic diagram which shows an example of a liquid crystal panel, (b) is a schematic diagram which shows the other example of a liquid crystal panel. (A) is an actual image of the fluorescent fine particles obtained when the fluorescent fine particles are fixed using the measuring device of the reference material and the sample stage is scanned in the z-axis direction, and (b) is (a) Is an analysis image of fluorescent fine particles obtained by fitting the image shown in (2) with a two-dimensional Gaussian function. 6 is a graph showing the relationship between W _x (Z) / W _y (Z) calculated from the image shown in FIG. 5 and Z. (A) is a luminescence image of the luminescent substance in the xy plane obtained at t seconds of the liquid crystal sample 1, and (b) is a luminescent substance in the xy plane obtained at t + Δt seconds of the liquid crystal sample 1. It is a light emission image of. (A) is for explaining that W _x (Z (t)) / W _y (Z (t)) at t seconds is determined by two-dimensional Gaussian fitting from the image shown in FIG. 7 (a). FIG. 7B shows that W _x (Z (t + Δt)) / W _y (Z (t + Δt)) at t + Δt seconds is determined by two-dimensional Gaussian fitting from the image shown in FIG. 7B. It is a figure for demonstrating. (A) is a histogram showing the diffusion coefficient D _x in the x-axis direction of the liquid crystal sample 1, (b) is a histogram showing the diffusion coefficient D _y in the y-axis direction of the liquid crystal sample 1, and (c) is 4 is a histogram showing a diffusion coefficient D _z in the z-axis direction of the liquid crystal sample 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the following description, in order to make each component easy to see, the scale of the dimension may be changed depending on the component in the drawings.

[Method for evaluating liquid crystal composition]
First, a liquid crystal evaluation method according to an embodiment of the present invention will be described.
FIG. 1 is a flowchart showing a procedure of a liquid crystal evaluation method in the present embodiment.

  As shown in FIG. 1, the liquid crystal evaluation method according to the present embodiment includes step S101 of preparing a liquid crystal sample containing a luminescent substance, and light emission that is excited in the liquid crystal sample while irradiating the liquid crystal sample with excitation light. Step S102 for measuring the three-dimensional spatial coordinates (x, y, z) of the luminescent substance to be performed, and the x, y, z axes of the liquid crystal molecules contained in the liquid crystal sample based on the measurement result of the luminescent substance Step S103 for evaluating movement in the direction.

  First, in step S101 shown in FIG. 1, the liquid crystal sample to be evaluated is not particularly limited, and examples include those containing (liquid crystal) described later.

  As the luminescent substance added to the liquid crystal sample, for example, a perylene diimide compound (PDI) shown below can be used.

In the above formula, R ¹ and R ² preferably represent an alkyl group having 1 to 14 carbon atoms, and more preferably represent an alkyl group having 5 to 10 carbon atoms.

  As for the molecular weight of the luminescent substance, it is preferable to use the same molecular weight as that of the liquid crystal molecules contained in the liquid crystal sample to be evaluated. Thereby, from the movement of the luminescent substance in the liquid crystal sample measured in step S102 described later, the movement and alignment state of the liquid crystal molecules in the liquid crystal sample can be analyzed at the molecular level.

  Note that the movement of the luminescent substance or liquid crystal molecules in the liquid crystal sample represents the overall movement of the luminescent substance or liquid crystal molecules in the liquid crystal sample (medium). Specifically, it represents a general movement including a movement behavior and displacement of a luminescent substance or liquid crystal molecules in a liquid crystal sample, and a direction and speed of displacement.

  The luminescent substance is not limited to the above PDI, and a luminescent compound that is excited by excitation light and emits light (fluorescence or phosphorescence) having a wavelength different from that of the excitation light can be used. Specifically, examples of the luminescent substance include Rhodamine dyes (also referred to as Atto and Alexa) and cyanine dyes (also referred to as Cy), in addition to the PDI. Moreover, a semiconductor quantum dot (CdSe system), a gold nano quantum, etc. can be mentioned.

The luminescent substance is preferably diffused in the liquid crystal sample. In order to diffuse the luminescent substance into the liquid crystal sample, the content (addition amount) of the luminescent substance contained in the liquid crystal sample is preferably 10 ⁻⁸ mol / L or less. When the content of the luminescent substance is too large, the luminescent substance aggregates, and it becomes difficult to appropriately analyze the movement and alignment state of liquid crystal molecules in the liquid crystal sample. In addition, a background signal other than the background object becomes strong, and it becomes difficult to obtain sufficient contrast for determining the movement and displacement of the object.

On the other hand, if the content of the luminescent substance is too small, it becomes difficult to measure the movement of the luminescent substance in the liquid crystal sample in step S102 described later. Therefore, the upper limit of the content of the luminescent substance is set to such a level (concentration) that the luminescent substance does not aggregate in the liquid crystal sample or the contrast of the target product is not lowered, and the lower limit of the content of the luminescent substance is excited. It is preferable that the light-emitting substance that emits light when excited by light is detected. The content of the luminescent substance that satisfies such conditions is particularly preferably in the range of 10 ⁻¹⁰ to 10 ⁻¹¹ mol / L. In addition, although it does not prescribe ^| regulate especially about the lower limit of content of a luminescent substance, it should ^{just be} at least 10 ^<-19 > mol / L or more.

  The liquid crystal sample may contain various additives ordinarily added as a liquid crystal material in addition to the liquid crystal and the light-emitting substance described above. That is, the liquid crystal sample is formed by adding a predetermined amount of a luminescent substance to the liquid crystal material in order to analyze the movement and alignment state of the liquid crystal molecules contained in the liquid crystal material.

  Next, in step S102 shown in FIG. 1, it is preferable to select light that does not cause absorption or emission of light that would hinder measurement, as the excitation light, and a sufficiently low background to this excitation light. It is preferable to use light whose wavelength and output are adjusted (optimized) so as to achieve a noise level.

  Specifically, a laser light source or a light emitting diode (LED) that emits light of a single wavelength (monochromatic) can be used as the light source that emits excitation light. As the excitation light, it is preferable to use monochromatic light capable of causing the luminescent substance to emit light in the visible light range. In general, when a luminescent substance is excited by excitation light, it emits monochromatic light having a wavelength longer than the wavelength of the excitation light. Therefore, even in the visible light region, monochromatic light (for example, blue light or blue green) It is preferable to use light, green light, etc.).

  Generally, when the luminescent substance is continuously irradiated with excitation light, the luminescent substance is eventually decomposed and the luminescent substance does not emit light. Therefore, in order to ensure sufficient time for measuring the luminescent substance, it is necessary to adjust the balance between the lifetime of the luminescent substance and the wavelength and output of the excitation light.

  On the other hand, if the output of the excitation light is reduced excessively in order to prevent decomposition of the luminescent substance, the detection sensitivity of the luminescent substance is lowered. That is, in order to be able to detect a luminescent substance that emits light when excited by excitation light, it is necessary to select a light source in consideration of the relationship with the detection sensitivity of the light.

  For measurement of the luminescent substance, for example, an image sensor such as a CCD or a CMOS can be used. When these image sensors are used, a high resolution of 10 nanometers or less can be obtained by image analysis, so that the movement of the luminescent substance in the liquid crystal sample can be measured at the molecular level.

  Moreover, it is preferable to measure a luminescent substance by time division. Thereby, it is possible to measure the movement including the movement behavior and displacement of the luminescent substance in the liquid crystal sample, and the direction and speed of the displacement. In addition, about the measurement of a luminescent substance, it is not necessarily limited to the measurement by such a time division. In addition, for example, the measurement may be performed continuously within a certain time, or the measurement may be performed at a certain point in time.

Here, an example of a measuring apparatus used in the present embodiment is shown in FIG.
FIG. 2 is a schematic diagram showing the configuration of the measuring device used in this embodiment.

  The measuring apparatus shown in FIG. 2 is a so-called inverted microscope, which is a laser light source 1, a condenser lens 2, a dichroic mirror 3, an objective lens 4, a sample stage 5, an excitation light cut filter 6, and a relay lens 7a. 7b, a polarizer 8, a cylindrical lens 9, an imaging lens 10, and an image sensor 11.

  Among these, the laser light source 1, the condenser lens 2, and the dichroic mirror 3 are arranged in this order on the same axis ax1. On the other hand, the sample stage 5, the objective lens 4, the dichroic mirror 3, the excitation light cut filter 6, the relay lenses 7 a and 7 b, the polarizer 8, the cylindrical lens 9, the imaging lens 10, and the image sensor 11. Are arranged in this order on the same axis ax2. The axis line ax1 and the axis line ax2 are orthogonal to each other in the same plane. A dichroic mirror 3 is disposed at the intersection of the axis line ax1 and the axis line ax2.

  The laser light source 1 is an argon laser, and emits, for example, blue-green laser light having a wavelength of 488 nm as the excitation light BL.

  The condenser lens 2 is for irradiating the excitation light BL emitted from the laser light source 1 as parallel light to the liquid crystal sample S on the sample stage 5.

  The dichroic mirror 3 reflects the excitation light BL toward the sample stage 5 and transmits fluorescent light YL, which will be described later, toward the image sensor 11.

  The objective lens 4 is arranged to irradiate the liquid crystal sample S on the sample stage 5 with the excitation light BL as parallel light. Further, the luminescent substance in the liquid crystal sample S can be focused by moving the objective lens 4 in the axial direction.

  The sample stage 5 is a moving stage on which the liquid crystal sample S is placed. In the sample stage 5, the position of the liquid crystal sample S can be moved in the x-axis, y-axis, and z-axis directions using a driving element such as a piezo element.

  The liquid crystal sample S is placed on the sample table 5 in a state of being sandwiched between transparent substrates, for example. When the liquid crystal sample S is irradiated with the excitation light BL, the luminescent substance in the liquid crystal sample S is excited. Thereby, the luminescent substance emits light (fluorescence light) YL having a wavelength different from that of the excitation light BL. The fluorescent light YL emitted from the luminescent substance passes through the objective lens 4 and then passes through the dichroic mirror 3.

  The excitation light cut filter 6 blocks the excitation light BL reflected by the objective lens 4 and transmitted through the dichroic mirror 3, the excitation light BL reflected by the liquid crystal sample S and transmitted through the dichroic mirror 3, and the like.

  The relay lenses 7a and 7b adjust the size of the fluorescent light YL in accordance with the size of the imaging surface of the imaging device 11.

  The polarizer 8 passes only the light of the polarization component in a specific direction out of the fluorescent light YL. The polarizer 8 can be removed from the optical path of the fluorescent light YL.

  The cylindrical lens 9 condenses the fluorescent light YL in one direction.

  The imaging lens 10 images the fluorescent light YL on the imaging surface of the imaging element 11.

  The image pickup device 11 is a CCD camera, and receives an image of a luminescent substance that emits the fluorescent light YL by receiving the fluorescent light YL formed on the imaging surface.

  The measuring apparatus shown in FIG. 2 includes a white light source 12, a projection lens 13, and a polarizer 14. The polarizer 14, the projection lens 13, and the white light source 12 are arranged in order from the sample stage 5 side on the axis ax2.

  The white light source 12 irradiates white light WL toward the sample S on the sample stage 5.

  The projection lens 13 enlarges and projects the white light WL emitted from the white light source 12 toward the liquid crystal sample S on the sample stage 5.

  The polarizer 14 passes only the light of the polarization component in a specific direction in the white light WL. The polarizer 14 can be removed from the optical path of the white light WL.

  In the present embodiment, the luminescent substance that emits the fluorescent light YL in the liquid crystal sample S is measured in a time-sharing manner while irradiating the liquid crystal sample S with the excitation light BL using the measurement device shown in FIG. Thereby, the image of the luminescent substance for every measurement time is acquired.

  Note that the polarizers 8 and 14 are irradiated with white light WL without irradiating the excitation light WL, and the alignment of the liquid crystal molecules in the liquid crystal sample S mainly by the polarization microscope along the axis ax2 in FIG. Used when analyzing the state. On the other hand, when measuring the movement of the luminescent substance in the liquid crystal sample S, the measurement is performed by irradiating the excitation light BL without irradiating the white light WL with the polarizers 8 and 14 removed. Can do.

Next, in step S103 shown in FIG. 1, after obtaining the moving distance per unit time of the luminescent substance from the acquired image of the luminescent substance, the diffusion coefficient of the liquid crystal molecules contained in the liquid crystal sample S is calculated. . Specifically, in the present embodiment, in order to analyze the three-dimensional movement, diffusion state, orientation state, and the like of the liquid crystal molecules contained in the liquid crystal sample S, the liquid crystal molecules contained in the liquid crystal sample S in the x-axis direction are analyzed. When the diffusion coefficient is D _x , the diffusion coefficient in the y-axis direction is D _y, and the diffusion coefficient in the z-axis direction is D _z , the respective diffusion coefficients D _x , D _y , D _z are expressed by the following formula (1) It can be calculated and calculated by any one of (3).

2D _x Δt = <{x (t + Δt) −x (t)} ² > (1)
2D _y Δt = <{y (t + Δt) −y (t)} ² > (2)
2D _z Δt = <{z (t + Δt) −z (t)} ² > (3)

  In the above formulas (1) to (3), x (t), y (t), and z (t) are the x coordinate of the center position of the light emitting point of the luminescent substance at t seconds, y X (t + Δt), y (t + Δt), and z (t + Δt) represent the x-coordinate, y-coordinate, and z-coordinate of the center position of the luminescent point of the luminescent material at t + Δt seconds, respectively.

In the above formulas (1) to (3), <> represents an average, for example, <{x (t + Δt) −x (t)} ² > represents a luminescent substance between t seconds and t + Δt seconds. Represents the root mean square of the distance moved in the x-axis direction.

  Here, the diffusion coefficient of the liquid crystal molecules is actually the diffusion coefficient of the luminescent substance obtained from the moving distance per unit time of the luminescent substance. In the present embodiment, it is considered that the liquid crystal molecules in the liquid crystal sample S exhibit the same movement reflecting the movement of the luminescent substance in the liquid crystal sample S. Therefore, the movement of the luminescent substance in the liquid crystal sample S. Is regarded as the movement of liquid crystal molecules in the liquid crystal sample S.

  Further, for example, when a substance other than liquid crystal molecules such as impurities is contained in the liquid crystal sample S, the impurities in the liquid crystal sample S move in the same manner reflecting the movement of the luminescent substance in the liquid crystal sample S. It is thought to show. Therefore, the movement of the luminescent substance in the liquid crystal sample S can be regarded as the movement of the impurity or the like in the liquid crystal sample S, and the movement of the impurity or the like in the liquid crystal sample S can be analyzed.

As described above, in the present embodiment, the movement and orientation state of the liquid crystal molecules in the liquid crystal sample S can be analyzed at the molecular level from the calculated diffusion coefficients D _x , D _y , D _z of the liquid crystal molecules. . As a result, it is possible to evaluate liquid crystal characteristics that have not been obtained so far.

  That is, in this embodiment, it is possible to analyze the three-dimensional movement, diffusion state, alignment state, and the like of liquid crystal molecules. Specifically, by analyzing the three-dimensional movement of the liquid crystal molecules with an accuracy of 10 nm or less, it is possible to analyze the alignment state of the liquid crystal molecules at the molecular level.

[LCD panel evaluation method]
Next, a liquid crystal panel evaluation method according to an embodiment of the present invention will be described.
FIG. 3 is a flowchart showing the procedure of the liquid crystal panel evaluation method in the present embodiment.

  As shown in FIG. 3, the evaluation method of the liquid crystal panel in the present embodiment is a liquid crystal panel in which a liquid crystal layer is disposed between substrates, and a liquid crystal in which a luminescent substance is added to the liquid crystal layer. Step S201 for preparing the panel, Step S202 for measuring the luminescent substance that emits light by being excited in the liquid crystal layer while irradiating the liquid crystal panel with excitation light, and the measurement result of the luminescent substance based on the measurement result of the luminescent substance. Step S203 for performing the evaluation.

  In other words, this liquid crystal panel evaluation method is basically the same method (measurement device) except that the liquid crystal sample S is an evaluation object in the above-described liquid crystal evaluation method, but the evaluation object is a liquid crystal panel. Can be used.

(LCD panel)
Here, a specific configuration of the liquid crystal panel will be described by taking the liquid crystal panel 20 illustrated in FIG. 4A and the liquid crystal panel 30 illustrated in FIG. 4B as examples.

  The liquid crystal panel 20 shown in FIG. 4A has a first substrate 21, a second substrate 22, and a liquid crystal layer 23 disposed between the first substrate 21 and the second substrate 22. .

  Alignment layers 24a and 24b for controlling the alignment state of the liquid crystal layer 23 and the alignment state of the liquid crystal layer 23 are generated by applying a driving voltage on the surfaces of the first substrate 21 and the second substrate 22 facing each other. Transparent electrodes 25a and 25b that are changed by an electric field are provided.

  For example, in the case of a horizontal alignment type such as a TN mode or an STN mode, the alignment layers 24a and 24b cause the liquid crystal molecules 23a of the liquid crystal layer 23 to move in a direction substantially horizontal to the substrate surface when no drive voltage is applied. Is oriented (horizontal orientation). Here, the substantially horizontal direction includes a horizontal direction and a substantially horizontal direction.

  On the other hand, in the case of the vertical alignment type such as the VA mode, the alignment layers 24a and 24b align the liquid crystal molecules 23a of the liquid crystal layer 23 in a direction substantially perpendicular to the substrate surface when no drive voltage is applied ( Vertical alignment). Here, the substantially vertical direction includes a vertical direction and a substantially vertical direction.

  The liquid crystal panel 20 may be in a passive matrix display format or an active matrix display format. In the case of the passive matrix display format, for example, the STN mode can be cited. In the STN mode, the transparent electrode 25a on the first substrate 21 and the transparent electrode 25b on the second substrate 22 are patterned in stripes so as to be orthogonal to each other.

  In the case of the active matrix display method, for example, a TN mode, a VA mode, and the like can be given. In the active matrix display system, a plurality of pixel electrodes are arranged in a matrix, and driving is controlled independently by a non-linear active element (not shown) electrically connected to each pixel electrode. The Therefore, in the active matrix display system, one of the transparent electrodes 25a and 25b is a pixel electrode, and the other is a common electrode.

  The liquid crystal panel 30 shown in FIG. 4B has a first substrate 31, a second substrate 32, and a liquid crystal layer 33 disposed between the first substrate 31 and the second substrate 32. .

  Alignment layers 34 a and 34 b for controlling the alignment state of the liquid crystal layer 23 are provided on the surfaces of the first substrate 21 and the second substrate 22 facing each other. A transparent electrode 35 that changes the alignment state of the liquid crystal layer 23 by an electric field generated by applying a driving voltage is provided on the surface of the first substrate 21 facing the second substrate 22.

  That is, the liquid crystal panel 30 has a configuration in which electrodes are provided only on one of the first substrate 21 and the second substrate 22. This configuration is applied to a horizontal alignment type such as an IPS mode. In the IPS mode, the alignment layers 34a and 34b align the liquid crystal molecules 33a of the liquid crystal layer 33 in a direction substantially horizontal to the substrate surface (horizontal alignment) when no drive voltage is applied. In the IPS mode, the transparent electrode 35 constitutes a comb electrode composed of a common electrode and a pixel electrode.

  In the present embodiment, measurement in a state where an electric field is applied to the liquid crystal layer 23 (when a drive voltage is applied) and measurement in a state where no electric field is applied to the liquid crystal layer 23 (when no drive voltage is applied). And do. Thereby, the movement and alignment state of the liquid crystal molecules 23a and 33a in the liquid crystal layers 23 and 33 accompanying the driving of the liquid crystal panels 20 and 30 can be analyzed at the molecular level. As a result, it is possible to evaluate the characteristics of the liquid crystal panels 20 and 30 that have not been obtained so far.

(liquid crystal)
Next, a specific example of the liquid crystal (liquid crystal layers 23 and 33) will be described.
Examples of the liquid crystal include a rod-like liquid crystal (nematic liquid crystal and smectic liquid crystal), a disk-like (discotic) liquid crystal, a bent liquid crystal (banana liquid crystal), and a liquid crystal obtained by adding chirality thereto. In addition, examples of the liquid crystal to which chirality is added include those in which a part or all of the liquid crystal is chiral, and liquid crystal mixed with chiral non-liquid crystal.

  The liquid crystal includes any one of a monomer, a dimer, a multimer (oligomer) higher than a trimer, and a polymer (polymer) as long as it can measure the diffusion of the luminescent compound. Also good.

<General formula (LC)>
Examples of the rod-like liquid crystal include compounds represented by the following general formula (LC).

In the general formula (LC), R ^LC represents an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group may be —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C, so that the oxygen atoms are not directly adjacent. It may be substituted with ≡C-. One or two or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom.

A ^LC1 and A ^LC2 each independently represent a group selected from the group consisting of the following (a) to (c).
(A) trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ groups not adjacent to each other may be substituted with an oxygen atom or a sulfur atom) .)
(B) 1,4-phenylene group (one CH group present in this group or two or more non-adjacent CH groups may be substituted with a nitrogen atom)
(C) 1,4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2 , 6-diyl group or a group selected from the group consisting of chroman-2,6-diyl group
One or two or more hydrogen atoms contained in the groups (a) to (c) may be substituted with F, Cl, CF ₃ or OCF ₃ , respectively.

Z ^LC is a single bond, —CH═CH—, —CF═CF—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—. _{, -OCF 2 -, - CF 2} O -, - COO- or an -OCO-.

Y ^LC represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, and an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group may be —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C, so that the oxygen atom is not directly adjacent. ≡C—, —CF ₂ O—, and —OCF ₂ — may be substituted. One or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom.

a is an integer of 1 to 4, a is 2, 3 or ^{4, if A LC1} there are multiple, ^{A LC1} presence of a plurality may be different even in the ^{same, Z LC} When there are a plurality of Z ^LCs , the plurality of Z ^LCs may be the same or different.

<General formula (LC1) and (LC2)>
Examples of the compound represented by the general formula (LC) include compounds represented by the following general formulas (LC1) and (LC2).

In the general formulas (LC1) and (LC2), R ^LC11 and R ^LC21 each independently represent an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group may be —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C, so that the oxygen atoms are not directly adjacent. It may be substituted with ≡C-. One or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom.

A ^LC11 and A ^LC21 each independently represent any of the following structures.

In the above structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with an oxygen atom. One or two or more CH groups in the 1,4-phenylene group may be substituted with a nitrogen atom. One or more hydrogen atoms in the structure may be substituted with F, Cl, CF ₃ or OCF ₃ .

^{X LC11, X LC12, X LC21} ~X LC23 represent each independently a hydrogen atom, Cl, F, and CF _3, or OCF _3.
Y ^LC11 and Y ^LC21 each independently represent a hydrogen atom, Cl, F, CN, CF ₃ , OCH ₂ F, OCHF ₂ or OCF ₃ .
Z ^LC11 and Z ^LC21 are each independently a single bond, —CH═CH—, ^{—CF═CF—} , ^—C≡C— , —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH _{2. -, - CH 2 O -,} - OCF 2 -, - CF 2 O -, - COO- or an -OCO-.
m ^LC11 and m ^LC21 each independently represent an integer of 1 to 4. When there are a plurality of A ^LC11 , A ^LC21 , Z ^LC11 and Z ^LC21 , they may be the same or different.

R ^LC11 and R ^LC21 each independently preferably represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms. It is more preferable to represent an alkyl group having 5 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms, and more preferably linear.

  Most preferably, the alkenyl group represents the following structure. In the following structure, the ring structure is bound at the right end.

A ^LC11 and A ^LC21 preferably each independently represent the following structure.

Y ^LC11 and Y ^LC21 each independently preferably represent F, CN, CF ₃ or OCF ₃ , more preferably represent F or OCF _3, and particularly preferably represent F.
Z ^LC11 and Z ^LC21 represent a single bond, —CH ₂ CH ₂ —, ^—COO— , ^—OCO— , —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—. Preferably, it represents a single bond, —CH ₂ CH ₂ —, —OCH ₂ —, —OCF ₂ — or —CF ₂ O—, and more preferably represents a single bond, —OCH ₂ — or —CF ₂ O—. Is more preferable.
m ^LC11 and m ^LC21 preferably represent an integer of 1, 2 or 3, preferably 1 or 2 when importance is attached to storage stability at low temperature and response speed, and the upper limit of the nematic phase upper limit temperature. To improve the value, it is preferable to represent 2 or 3.

<General Formulas (LC1-a) to (LC1-c)>
Examples of the compound represented by the general formula (LC1) include compounds represented by the following general formulas (LC1-a) to (LC1-c).

In formula (LC1-a) ~ (LC1 -c), R LC11, Y LC11, X LC11 and ^{X LC12} is, ^R LC11 in the general formula each independently ^{(LC1), Y LC11, X} LC11 and X ^The meaning is the same as ^LC12 .

A ^LC1a1 , A ^LC1a2 and A ^LC1b1 represent a trans-1,4-cyclohexylene group, a tetrahydropyran-2,5-diyl group, and a 1,3-dioxane-2,5-diyl group.
^{X LC1b1, X LC1b2, X LC1c1} ~X LC1c4 represent each independently a hydrogen atom, Cl, F, and CF _3, or OCF _3.

R ^LC11 preferably independently represents an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms, and has 1 to 5 carbon atoms. More preferably, it represents an alkyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms.
X ^{LC11 to} X ^LC1c4 preferably each independently represent a hydrogen atom or F.
Y ^LC11 preferably independently represents F, CF ₃ or OCF ₃ .

<General Formulas (LC1-d) to (LC1-m)>
Examples of the compound represented by the general formula (LC1) include compounds represented by the following general formulas (LC1-d) to (LC1-m).

In formula (LC1-d) ~ (LC1 -m), R LC11, Y LC11, X LC11 and ^{X LC12} is, ^R LC11 in the general formula each independently ^{(LC1), Y LC11, X} LC11 and X ^The meaning is the same as ^LC12 .

^ALC1d1 , ^ALC1f1 , ^ALC1g1 , ^ALC1j1 , ^ALC1k1 , ^ALC1k2 , ^{ALC1m1 to ALC1m3} are 1,4-phenylene group, trans-1,4-cyclohexylene group, tetrahydropyran-2,5-diyl Group represents a 1,3-dioxane-2,5-diyl group.
^{X LC1d1, X LC1d2, X LC1f1} , X LC1f2, X LC1g1, X LC1g2, X LC1h1, X LC1h2, X LC1i1, X LC1i2, X LC1j1 ~X LC1j4, X LC1k1, X LC1k2, X LC1m1 and ^{X LC1m2} each Independently represents a hydrogen atom, Cl, F, CF ₃ or OCF ₃ .
Z ^LC1d1 , Z ^LC1e1 , Z ^LC1j1 , Z ^LC1k1 and Z ^LC1m1 are each independently a single bond, —CH═CH—, ^{—CF═CF—} , ^—C≡C— , —CH ₂ CH ₂ —, — ( CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ —, —CF ₂ O—, —COO— or —OCO— are represented.

R ^LC11 preferably independently represents an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms, and has 1 to 5 carbon atoms. More preferably, it represents an alkyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms.
X ^{LC11 to} X ^LC1m2 each preferably independently represents a hydrogen atom or F.
Y ^LC11 preferably independently represents F, CF ₃ or OCF ₃ .
Z ^{LC1d1 to} Z ^LC1m1 preferably each independently represent —CF ₂ O— or —OCH ₂ —.

<General Formulas (LC2-a) to (LC2-g)>
Examples of the compound represented by the general formula (LC2) include compounds represented by the following general formulas (LC2-a) to (LC2-g).

In the general formulas (LC2-a) to (LC2-g), R ^LC21 , Y ^LC21 , X ^{LC21 to} X ^LC23 are each independently R ^LC21 , Y ^LC21 , X ^{LC21 to} X LC in the general formula (LC2). ^The meaning is the same as ^LC23 .
^{X LC2d1 ~X LC2d4, X LC2e1 ~X} LC2e4, X LC2f1 ~X LC2f4 and ^X LC2g1 ^{~X LC2g4} represent each independently a hydrogen atom, Cl, F, and CF _3, or OCF _3.
Z ^LC2a1 , Z ^LC2b1 , Z ^LC2c1 , Z ^LC2d1 , Z ^LC2e1 , Z ^LC2f1 and Z ^LC2g1 are each independently a single bond, —CH═CH—, ^{—CF═CF—} , ^{—CF═CF—} , ^—C≡C— , —CH _2. It represents CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ —, —CF ₂ O—, —COO— or —OCO—.

R ^LC21 preferably independently represents an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms, and has 1 to 5 carbon atoms. More preferably, it represents an alkyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms.
X ^{LC21 to} X ^LC2g4 are each independently preferably a hydrogen atom or F.
Y ^LC21 preferably independently represents F, CF ₃ or OCF ₃ .
Z ^{LC2a1 to} Z ^LC2g4 preferably each independently represent —CF ₂ O— or —OCH ₂ —.

<General Formulas (LC3) to (LC5)>
Examples of the compound represented by the general formula (LC) include compounds represented by the following general formulas (LC3) to (LC5).

In the general formula ^{(LC3) ~ (LC5),} R LC31, R LC32, R LC41, R LC42, R LC51 and ^{R LC52} represents an alkyl group having 1-15 carbon atoms independently. One or more CH ₂ groups in the alkyl group may be —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C, so that the oxygen atoms are not directly adjacent. ≡C— may be substituted. One or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom.

^{A LC31, A LC32, A LC41} , A LC42, A LC51 and ^{A LC52} each independently represent any structure below.

In the above structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with an oxygen atom. One or two or more CH groups in the 1,4-phenylene group may be substituted with a nitrogen atom. One or more hydrogen atoms in the structure may be substituted with Cl, CF ₃ or OCF ₃ .

^{Z LC31, Z LC32, Z LC41} , Z LC42, Z LC51 and ^{Z LC51} are each independently a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) _{4 -, - COO -, -} OCH 2 -, - CH 2 O -, - OCF 2 - or an _-CF 2 O-.
Z ⁵ represents a CH ₂ group or an oxygen atom.
X ^LC41 represents a hydrogen atom or a fluorine atom.
^{m LC31, m LC32, m LC41} , m LC42, m LC51 and ^{m LC52} are each independently an integer of ^{0~3, m LC31 + m LC32,} m LC41 + m LC42 and ^m LC51 ^{+ m LC52} is 1,2 Or 3. When a plurality of A ^{LC31 to} A ^LC52 and Z ^{LC31 to} Z ^LC52 are present, they may be the same or different.

R ^{LC31 to} R ^LC52 each independently preferably represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms.

  Most preferably, the alkenyl group represents the following structure. In the following structure, the ring structure is bound at the right end.

A ^{LC31 to} A ^LC52 preferably each independently represent the following structure.

Z ^{LC31 to} Z ^LC51 are each independently a single bond, —CH ₂ O—, —COO—, ^—OCO— , —CH ₂ CH ₂ —, —CF ₂ O—, —OCF ₂ — or —OCH ₂ —. Is preferably represented.

<General Formulas (LC3-a) and (LC3-b)>
Examples of the compound represented by the general formula (LC3) include compounds represented by the following general formulas (LC3-a) and (LC3-b).

In the general formulas (LC3-a) and (LC3-b), R ^LC31 , R ^LC32 , A ^LC31 and Z ^LC31 are each independently R ^LC31 , R ^LC32 , A ^LC31 and Z in the general formula (LC3). ^The meaning is the same as ^LC31 .

X ^{LC3b1 to} X ^LC3b6 represent a hydrogen atom or a fluorine atom, but at least one combination of X ^LC3b1 and X ^LC3b2 or X ^LC3b3 and X ^LC3b4 represents a fluorine atom.
m ^LC3a1 represents an integer of 1, 2 or 3, and m _LC3b1 represents an integer of 0 or 1. When a plurality of A ^LC31 and Z ^LC31 are present, they may be the same or different.

R ^LC31 and R ^LC32 are each independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, or an alkenyloxy having 2 to 7 carbon atoms. It is preferable to represent a group.
A ^LC31 preferably represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a tetrahydropyran-2,5-diyl group, or a 1,3-dioxane-2,5-diyl group. , 4-phenylene group and trans-1,4-cyclohexylene group are more preferable.
Z ^LC31 is a single _{bond, -CH 2 O -, - COO} -, - OCO -, - CH 2 CH 2 - is preferred to represent, and more preferably a single bond.

<General Formulas (LC3-a1) to (LC3-a4)>
Examples of the compound represented by the general formula (LC3-a) include compounds represented by the following general formulas (LC3-a1) to (LC3-a4).

In the general formulas (LC3-a1) to (LC3-a4), R ^LC31 and R ^LC32 each independently represent the same meaning as R ^LC31 and R ^LC32 in the general formula (LC3).

R ^LC31 and R ^LC32 each independently preferably represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms, and R ^LC31 is a carbon atom. More preferably, it represents an alkyl group having 1 to 7 atoms, and R ^LC32 represents an alkoxy group having 1 to 7 carbon atoms.

<General Formulas (LC3-b1) to (LC3-b12)>
Examples of the compound represented by the general formula (LC3-b) include compounds represented by the following general formulas (LC3-b1) to (LC3-b12). Among these, compounds represented by general formulas (LC3-b1), (LC3-b6), (LC3-b8), and (LC3-b11) are more preferable, and general formulas (LC3-b1) and (LC3 -B6) is more preferable, and a compound represented by the general formula (LC3-b1) is most preferable.

In the general formulas (LC3-b1) to (LC3-b12), R ^LC31 and R ^LC32 each independently represent the same meaning as R ^LC31 and R ^LC32 in the general formula (LC3).

R ^LC31 and R ^LC32 each independently preferably represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms, and R ^LC31 is a carbon atom. More preferably, it represents an alkyl group having 2 or 3 atoms, and R ^LC32 represents an alkyl group having 2 carbon atoms.

<General Formulas (LC4-a) to (LC4-c)>
<General Formulas (LC5-a) to (LC5-c)>
Examples of the compound represented by the general formula (LC4) include compounds represented by the following general formulas (LC4-a) to (LC4-c). Examples of the compound represented by the general formula (LC5) include compounds represented by the following general formulas (LC5-a) to (LC5-c).

In the general formulas (LC4-a) to (LC4-c), R ^LC41 , R ^LC42 and X ^LC41 each independently represent the same meaning as R ^LC41 , R ^LC42 and X ^LC41 in the general formula (LC4). . In formula (LC5-a) ~ (LC5 -c), R LC51 and ^{R LC52} each independently represents the same meaning as ^{R LC51} and ^{R LC52} in formula (LC5).

^{Z LC4a1,} Z LC4b1, Z ^LC4c1 and ^{Z LC5a1, Z LC5b1, Z LC5c1} are each independently a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) _{4 -, - COO -, -} OCH 2 -, - CH 2 O -, - OCF 2 - or an _-CF 2 O-.

^{R LC41,} R ^LC42 and ^{R LC51, R LC52} is independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkenyl group, or number of carbon atoms of 2 to 7 carbon atoms It preferably represents 2 to 7 alkenyloxy groups.
Z ^LC4a1 , Z ^LC4b1 , Z ^LC4c1 and Z ^LC5a1 , Z ^LC5b1 , Z ^LC5c1 may each independently represent a single bond, —CH ₂ O—, ^—COO— , ^—OCO— , —CH ₂ CH ₂ —. Preferably, it represents a single bond.

<General formula (LC6)>
Examples of the compound represented by the general formula (LC) include a compound represented by the following general formula (LC6).

In the general formula (LC6), R ^LC61 and R ^LC62 each independently represent an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group may be —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C, so that the oxygen atoms are not directly adjacent. ≡C— may be substituted. One or more hydrogen atoms in the alkyl group may be optionally halogen-substituted.

A ^{LC61 to} A ^LC63 preferably each independently represent the following structure.

In the above structure, one or more CH ₂ CH ₂ groups in the cyclohexylene group may be substituted with —CH═CH—, —CF ₂ O—, —OCF ₂ —. One or two or more CH groups in the 1,4-phenylene group may be substituted with a nitrogen atom.

Z ^LC61 and Z ^LC62 each independently represent a single bond, —CH═CH—, ^—C≡C— , —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O— is represented.
^miii1 represents an integer of 0 to 3.

R ^LC61 and R ^LC62 each independently preferably represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms.

  Most preferably, the alkenyl group represents the following structure. In the following structure, the ring structure is bound at the right end.

A ^{LC61 to} A ^LC63 preferably each independently represent the following structure.

Z ^LC61 and Z ^LC62 each independently represent a single bond, —CH ₂ CH ₂ —, ^—COO— , —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—. preferable.

<General Formulas (LC6-a) to (LC6-m)>
Examples of the compound represented by the general formula (LC6) include compounds represented by the following general formulas (LC6-a) to (LC6-m).

In the general formulas (LC6-a) to (LC6-m), R ^LC61 and R ^LC62 each independently represent an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or the number of carbon atoms. An alkenyl group having 2 to 7 carbon atoms or an alkenyloxy group having 2 to 7 carbon atoms is represented.

(Other)
In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

For example, in the above embodiment, in order to analyze the three-dimensional movement, diffusion state, alignment state, and the like of the liquid crystal molecules in the liquid crystal sample S, the x axis, y axis, and z axis of the liquid crystal molecules contained in the liquid crystal sample S are analyzed. Although the case where the diffusion coefficients D _x , D _y , and D _z in the direction are calculated has been described, the diffusion coefficient of the liquid crystal molecules is diffusion in any one of the x-axis, y-axis, and z-axis directions (one-axis direction). Even when the coefficients D _x , D _y , and D _z are obtained, any two (biaxial direction) diffusion coefficients D _x , D _y , and D _z may be obtained.

In the present embodiment, the liquid crystal and the liquid crystal panels 20 and 30 can be evaluated in a multifaceted manner based on the measurement results, not limited to the case where the diffusion coefficients D _x , D _y , and D _z described above are calculated. It is. For example, based on the measurement result, the viscosity of the liquid crystal is evaluated, or the state of the surface (pixel electrode, alignment layer, etc.) on the side where the liquid crystal layers 23, 33 of the liquid crystal panels 20, 30 are arranged is evaluated. It is possible. Moreover, it is also possible to apply the evaluation method of this embodiment to the inspection process when manufacturing the liquid crystal panels 20 and 30.

  In addition, the measurement apparatus used in the present embodiment is not limited to the one shown in FIG. 2, and an optimum measurement apparatus can be appropriately selected and used in accordance with the measurement method of the present embodiment. Is possible.

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

(Reference sample)
In this example, a reference sample was prepared and the reference sample was measured before evaluating the liquid crystal. Specifically, first, a microscope cover glass having a thickness of 0.15 mm was ultrasonically washed with ethanol and 1M aqueous potassium hydroxide solution alternately for 20 minutes, and finally ultrasonically washed with ultrapure water for 10 minutes. did. Thereafter, the substrate was sufficiently dried with nitrogen gas.

  Next, an aqueous solution containing spherical fluorescent fine particles (trade name: FS02F, manufactured by Bangs Laboratories) was diluted 2000 times with pure water, and 100 μL of this solution was dropped onto the cover glass, and a spin coater (product) Name: K-359 S-1, manufactured by Kyowa Riken Co., Ltd.) and spin-coated for 30 seconds at 3000 rpm. Thereafter, the substrate was vacuum-dried for 3 hours to prepare a reference sample in which fluorescent fine particles were scattered on a cover glass.

  Next, the state of the fluorescent fine particles on the cover glass in the reference sample was measured with an atomic force microscope (trade name: MPF-3D, manufactured by Asylum Research). As a result, it was confirmed that the fluorescent fine particles were single-diffused on the substrate without being aggregated in a thickness of 7.0 nm.

  Next, an inverted microscope (trade name: IX71, manufactured by Olympus Corporation) similar to the measurement apparatus shown in FIG. 2 was prepared. Then, after placing the reference sample on the sample stage, excitation light is introduced from an Ar-Kr ion laser (trade name: Innova, Coherent) as an excitation light source, and a dichroic mirror (trade name: FF495-Di2-25 × 36, manufactured by Semrock Co., Ltd.), and the reference sample was irradiated with declining excitation light through an objective lens (× 100 product name: UPLSAPO NA 1.3 Oil-immersion, manufactured by Olympus).

  Next, a two-dimensional fluorescence image emitted from the fluorescent fine particles of the reference sample is converted into an excitation light cut filter (trade name: FF02-525 / 40-25 Band-pass filter 498-554 nm, manufactured by Semirock), a cylindrical lens (good cylindrical surface ratio). After passing in the order of convex lens f = 200-700 mm, manufactured by Sigma Kogyo Co., Ltd., the position of the lens in the optical path was adjusted so as to form an image on EM-CCD (iXon, manufactured by Andor Technology). Furthermore, the position where the emission image of the fluorescent fine particles of the reference sample is circular was set to Z = 0 nm. At this position, the focus is on the fluorescent fine particles.

  Next, it was measured how the emission image changes when the focus of the fluorescent fine particles is shifted up and down by the following method. As for the sample stage, a piezo stage (trade name: NS4312-C, manufactured by Nano Control) is used as a speed of 25 nm / second from Z = −500 nm to Z = + 500 nm using a 3-axis controller (trade name: NC3301-CNano Control). As a result of moving the reference sample in the vertical (z-axis) direction, 500 emission images from the fluorescent fine particles of the reference sample were taken every 0.1 second.

  Here, an image was obtained in which the vertical and horizontal ratios of the light emitting points were determined to be one for an arbitrary z coordinate. The acquired image is shown in FIG. The z-coordinate of the luminescent image observed at this time t [second] can be expressed as Z = 25t−500 [nm]. Further, an analysis image obtained by fitting a light emitting point in the range of Z = ± 500 [nm] with the following two-dimensional Gaussian function was obtained. The acquired image is shown in FIG.

In the above formula, h represents an emission peak value. x ₀ and y ₀ represent the X coordinate and y coordinate of the center of the light emitting point, respectively. W _x (Z) and W _y (Z) represent the widths of the light emitting points in the x-axis and y-axis directions, respectively, in Z. b corresponds to the background.

Next, after obtaining the values of W _x (Z) and W _y (Z) for each Z, the variance W _x (Z) in the x-axis direction of the light emitting point on the xy plane is obtained on the xy plane. A value W _x (Z) / W _y (Z) obtained by dividing by the dispersion W _y (Z) in the x-axis direction of the light emitting point was determined. And the curve which shows the relationship between this _Wx (Z) / _Wy (Z) and Z was obtained. This curve is shown in FIG. This curve was used as a calibration curve for determining the z coordinate of the liquid crystal sample 1 described later.

(Liquid crystal sample 1)
Next, a liquid crystal sample 1 to be evaluated was prepared. Specifically, a microscope cover glass having a thickness of 0.15 mm and a slide glass having a thickness of 0.7 mm were ultrasonically washed with ethanol and a 1M potassium hydroxide aqueous solution alternately for 20 minutes. Finally, ultrasonic cleaning was performed with ultrapure water for 10 minutes. After sufficiently drying these two substrates with nitrogen gas, each substrate is fixed with a UV-effective epoxy resin (trade name: Norland Optical Adhesive 61, manufactured by Norland) so as to form a gap of 8.6 μm in thickness. did.

  Next, N, N′-dioctyl-3,4,9,10-perylenediimide (PDI) is used as a luminescent substance in a liquid crystal showing a nematic phase at room temperature (trade name: RD-001, manufactured by DIC). A mixture (fluid) was prepared by mixing (made by Ardrich) so as to have a concentration of 10-10 M, and this mixture was injected between the two glass substrates by capillary action. Thereby, the liquid crystal sample 1 sandwiched between substrates having a gap of 8.6 μm in thickness was produced.

  Next, the liquid crystal sample 1 is placed on the sample stage of the measuring apparatus with the microscope cover glass facing downward, and a polarizer is placed between the liquid crystal sample 1 and the white light source and between the liquid crystal sample 1 and the EM-CCD, respectively. It set so that it might become a relation of orthogonal cross Nicole. At this time, the excitation light was cut by a shutter so as not to enter the liquid crystal sample 1.

  Next, when a white light source was turned on and an image when the liquid crystal sample 1 was rotated in the xy plane was observed with an EM-CCD, images of polydomains of various colors were obtained. Therefore, it was confirmed that the liquid crystal composition contained in the liquid crystal sample 1 was not oriented in the monodomain because no clear extinction position was observed.

  Next, the two light polarizers were removed, the white light source was turned off, the excitation light shutter was opened, and the liquid crystal sample 1 was irradiated with falling-down excitation light.

  Next, a luminescence image of the luminescent substance was acquired in a time division manner during the time t [second]. Specifically, without moving the sample stage, 500 images of the luminescent material were taken every 0.030 seconds for 15 seconds. FIGS. 7A and 7B show emission images of the obtained luminescent substance. FIG. 7A is a luminescence image of the luminescent substance in the xy plane obtained at t seconds of the liquid crystal sample 1. FIG. 7B is a luminescence image of the luminescent substance in the xy plane obtained at t + Δt seconds of the liquid crystal sample 1.

  As shown in FIGS. 7 (a) and 7 (b), the luminescent substance is xy from the position at t seconds shown in FIG. 7 (a) to the position at t + Δt seconds shown in FIG. 7 (a) after Δt seconds. It can be seen that they are moving by diffusion in the plane. In addition, in the luminescent image of the luminescent substance shown in FIGS. 7A and 7B, the ratio of the width in the x-axis direction to the width in the y-direction of the luminescent point is changed, so that from t seconds to t + Δt seconds. In the meantime, it can be seen that the luminescent material is also diffused and moved in the z-axis direction.

  Next, from the luminescent image of the luminescent substance shown in FIGS. 7A and 7B, the x-coordinate x (t) and y-coordinate y (t) of the center position of the luminescent point at t seconds, and at t + Δt time. The x-coordinate x (t + Δt) and the y-coordinate y (t + Δt) of the center position of the light emitting point were determined by two-dimensional Gaussian fitting, respectively.

Next, the diffusion coefficient D _x in the x-axis direction of the liquid crystal sample 1 was calculated from the center position of the light emitting point at x (t) and x (t + Δt) of the x coordinate using the above formula (1). Similarly, the diffusion coefficient D _y in the y-axis direction of the liquid crystal sample 1 was calculated from the center position of the light emitting point at y (t) and y (t + Δt) of the y coordinate using the above formula (2).

Further, a two-dimensional Gaussian fitting image of the luminescent point of the luminescent substance at t seconds was determined from the luminescent image of the luminescent substance at t seconds shown in FIG. 7A as shown in FIG. 8A. In FIG. 8A, the left side shows a luminescence image at t seconds of the luminescent substance shown in FIG. 7A, and the right side shows the two-dimensional Gaussian fitting image. Then, from this two-dimensional Gaussian fitting image, the value of W _x (Z (t)) / W _y (Z (t)) of the light emitting point at time t was determined. Further, by substituting the value of W _x (Z (t)) / W _y (Z (t)) into the calibration curve shown in FIG. 6, the Z position Z (t) of the luminescent substance at t seconds is obtained. Were determined.

Similarly, a two-dimensional Gaussian fitting image of the luminescent point at t + Δt seconds was determined from the luminescent image at t + Δt seconds of the luminescent substance shown in FIG. 7B as shown in FIG. 8B. . In FIG. 8B, the left side shows a luminescence image at t + Δt seconds of the luminescent substance shown in FIG. 7B, and the right side shows the two-dimensional Gaussian fitting image. Then, from this two-dimensional Gaussian fitting image, the _value of W _x (Z (t + Δt)) / W _y (Z (t + Δt)) of the light emitting point at t + Δt seconds was determined. Further, by substituting the value of W _x (Z (t + Δt)) / W _y (Z (t + Δt)) into the calibration curve shown in FIG. 6, the Z position Z (t + Δt) of the luminescent substance at t + Δt seconds is obtained. Were determined.

Then, the diffusion coefficient D _z in the z-axis direction of the liquid crystal sample 1 was calculated from the positions of Z (t) and Z (t + Δt) using the above formula (3).

Next, FIG. 9A shows a histogram of the diffusion coefficient D _x in the x-axis direction of the liquid crystal sample 1 calculated from the above equation (1). Further, FIG. 9B shows a histogram of the diffusion coefficient D _y in the y-axis direction of the liquid crystal sample 1 calculated from the above equation (2). Further, it shows a histogram of the diffusion coefficient D _z in the z-axis direction of the liquid crystal sample 1 calculated from the equation (3) in FIG. 9 (c).

From the results shown in FIGS. 9A to 9C, the average values D _x ave, D _y ave, and D _z ave of the diffusion coefficients D _x , D _y , and D _z of the liquid crystal sample 1 are 0.67, 0.80 and 0.61 [μm ² / s].

In the liquid crystal sample 1, since the liquid crystal is not aligned in the mono domain, it is considered that no clear difference is observed for each of the diffusion coefficients D _x , D _y , and D _z of the liquid crystal sample 1. In addition, it can be seen that the state of diffusion in the z-axis direction can be obtained with an accuracy of 1 μm or less in spite of the thin gap of 8.6 μm.

DESCRIPTION OF SYMBOLS 1 ... Laser light source 2 ... Condenser lens 3 ... Dichroic mirror 4 ... Objective lens 5 ... Sample stand 6 ... Excitation light cut filter 7a, 7b ... Relay lens 8 ... Polarizer 9 ... Cylindrical lens 10 ... Imaging lens 11 ... Imaging element 12 DESCRIPTION OF SYMBOLS ... White light source 13 ... Projection lens 14 ... Polarizer S ... Sample BL ... Excitation light YL ... Fluorescence light 20, 30 ... Liquid crystal panel 21, 31 ... 1st board | substrate 22, 32 ... 2nd board | substrate 23, 33 ... Liquid crystal layer 23a, 33a ... liquid crystal molecules 24a, 24b, 34a, 34b ... alignment layers 25a, 25b, 35 ... transparent electrodes

Claims (13)

Preparing a liquid crystal sample containing a luminescent material;
Measuring three-dimensional spatial coordinates (x, y, z) of a luminescent substance that emits light when excited in the liquid crystal sample while irradiating the liquid crystal sample with excitation light;
Evaluating the movement of the liquid crystal molecules contained in the liquid crystal sample in the x-, y-, and z-axis directions based on the measurement result of the luminescent substance.   The liquid crystal evaluation method according to claim 1, wherein the luminescent substance is diffused in the liquid crystal sample. The method for evaluating a liquid crystal according to claim 2, wherein the content of the luminescent substance contained in the liquid crystal sample is 10 ^-8 mol / L or less.   While irradiating the liquid crystal sample with excitation light, an image of the luminescent material that emits light having a wavelength different from that of the excitation light in the liquid crystal sample is acquired, so that the three-dimensional spatial coordinates (x , Y, z) is measured, The liquid crystal evaluation method according to any one of claims 1 to 3.   The method for evaluating a liquid crystal according to any one of claims 1 to 4, wherein three-dimensional spatial coordinates (x, y, z) of the luminescent substance are simultaneously measured.   6. The liquid crystal evaluation method according to claim 1, wherein the luminescent substance is measured in a time-sharing manner.   The liquid crystal evaluation method according to claim 6, wherein a diffusion coefficient of the liquid crystal molecules is obtained from a moving distance per unit time of the luminescent substance.   The liquid crystal evaluation method according to claim 7, wherein a diffusion coefficient of the liquid crystal molecules in at least two axial directions in the liquid crystal sample is obtained. The diffusion coefficient in the x-axis direction of liquid crystal molecules included in the liquid crystal sample and D _x, the diffusion coefficient in the y-axis direction and D _y, the diffusion coefficient in the z-axis direction is taken as D _z, each of the diffusion coefficient The method for evaluating a liquid crystal according to claim 7 or 8, wherein D _x , D _y , and D _z are calculated and calculated by any one of the following formulas (1) to (3).
2D _x Δt = <{x (t + Δt) −x (t)} ² > (1)
2D _y Δt = <{y (t + Δt) −y (t)} ² > (2)
2D _z Δt = <{z (t + Δt) −z (t)} ² > (3)
(In the above formulas (1) to (3), x (t), y (t), and z (t) are the x-coordinate and y-coordinate of the center position of the luminescent point of the luminescent material at t seconds Z (t + Δt), y (t + Δt), and z (t + Δt) represent the x, y, and z coordinates of the center position of the luminescent point of the luminescent material at t + Δt seconds, respectively.   The liquid crystal evaluation method according to claim 1, wherein the movement or alignment state of the liquid crystal molecules is analyzed based on a measurement result of the luminescent substance.   The liquid crystal evaluation method according to claim 1, wherein measurement is performed in a state where the liquid crystal sample is sandwiched between substrates. A method for evaluating a liquid crystal panel in which a liquid crystal layer is disposed between substrates,
Preparing a liquid crystal panel to which a luminescent material is added in the liquid crystal layer;
Measuring the three-dimensional spatial coordinates (x, y, z) of a luminescent substance that emits light when excited in the liquid crystal layer while irradiating the liquid crystal panel with excitation light;
Evaluating the liquid crystal panel based on the measurement result of the luminescent substance, and a liquid crystal panel evaluation method.   13. The method for evaluating a liquid crystal panel according to claim 12, wherein measurement is performed with an electric field applied to the liquid crystal layer, and measurement is performed with no electric field applied to the liquid crystal layer.