JP2008058496A - Liquid crystal display element and projection liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display element capable of reducing a quantity of ionic impurities in a liquid crystal cell, suppressing the occurrence of a burning phenomenon and obtaining higher image quality, and to provide a projection liquid crystal display device. <P>SOLUTION: The liquid crystal display element 10 has a liquid crystal layer 16 held between a pair of substrates 11 and 12 which are stuck with a sealing material 15 so that alignment layers are opposed to each other at prescribed intervals, wherein the content of a photo-radical polymerization initiator is less than 0.05 wt.% based on 100 pts.wt. sealant mother material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display element in which a liquid crystal layer is sandwiched between a pair of substrates bonded with a sealing material so that alignment films face each other with a predetermined gap, and a projection type liquid crystal display device using the liquid crystal display element. is there.

  In a projection type liquid crystal display device such as a liquid crystal projector, light emitted from a light source is separated into red, green and blue, and each color light is modulated by three light valves composed of liquid crystal display elements (hereinafter referred to as LCD). Then, the modulated color light fluxes are synthesized again and enlarged and projected onto the projection surface.

As a light valve mounted on a liquid crystal projector or the like, an active matrix driving type LCD driven by a thin film transistor (hereinafter referred to as TFT) is generally used.
As a display method of the active matrix driving method, there is a twisted nematic (TN type) liquid crystal having a molecular arrangement twisted by 90 degrees.

By the way, in recent years, a vertical alignment type liquid crystal element has begun to be studied in order to increase the brightness, the contrast, the definition, and the life of the liquid crystal projector.
Here, the vertically aligned liquid crystal material is a liquid crystal material having a negative dielectric anisotropy (the difference between the dielectric constant ε = parallel to the liquid crystal molecule major axis and the vertical dielectric constant ε⊥ is negative). Since the liquid crystal molecules are aligned substantially perpendicular to the substrate surface when the voltage applied to the liquid crystal is zero, this vertical alignment type liquid crystal display element can obtain a very high contrast ratio.
This vertical alignment type liquid crystal display element is used for both transmission type and reflection type, and is expected to become the mainstream of liquid crystal projectors in the future along with the inorganicization of the alignment film for the purpose of extending the lifetime.

In order to perform display on an active matrix LCD uniformly, it is necessary to align liquid crystal molecules uniformly over the entire surface of the substrate.
The two substrates on which the alignment film is formed and the electrodes are formed are arranged so that the alignment films of each substrate are opposed to each other, and in the seal region located around the pixel display region where an image is actually displayed, Affixed with a sealing material.
In recent years, columnar spacers made of resist are used to control the substrate gap.
An empty cell is manufactured through these steps. Thereafter, liquid crystal is sealed in the empty cell to manufacture a liquid crystal cell.
Note that the above-described liquid crystal is composed of several types of single liquid crystal materials and is also called a liquid crystal composition. A polarizing plate is attached to the manufactured liquid crystal cell to manufacture a liquid crystal display element.
Various liquid crystal display elements including materials have been proposed (see Patent Documents 1 to 4).
JP 2005-306949 A JP 2003-119248 A JP 2003-119249 A JP 2006-22228 A JP 2001-255562 A

  However, in these liquid crystal display elements, when the same screen is displayed for a long time, a problem of so-called burn-in that the display remains when the display is switched may occur.

1A to 1D are diagrams illustrating an example of an assumed model for occurrence of burn-in.
In FIG. 1, 1 is a TFT array substrate, 2 is a counter substrate, 3 and 4 are alignment film layers, and 5 is a liquid crystal layer.

  In the liquid crystal cell, ionic impurities contained in peripheral materials such as the alignment film layers 3 and 4 and the seal in the liquid crystal material of the liquid crystal layer 5 and various ionic impurities adhering in the process are mixed. (Fig. 1 (A)).

As shown in FIG. 1B, when an ionic impurity is adsorbed on the alignment film 3 of the substrate 1, an electric double layer composed of the alignment film layer 3 and the impurity layer is formed.
In manufacturing two substrates, for example, the TFT substrate 1 and the counter substrate 2, it is difficult to perform exactly the same processing, and the adsorption power of each impurity is not the same. As described above, since the amount of adsorption differs for each substrate, the voltage applied to the counter electrode (hereinafter referred to as Vcom voltage) shifts. When the signal voltage is reversed between positive and negative, the strength of the electric field (effective voltage) actually applied to the liquid crystal molecules varies depending on the inversion period.
As a result, the liquid crystal molecules fluctuate and a flickering phenomenon such as flicker occurs.

  When the display is continued at a Vcom voltage that causes flicker, the signal balance is lost in the positive and negative signals as shown in FIG. 1C, so that a DC component is applied to the liquid crystal molecules. Since a direct current component is always applied to one substrate, ionic impurities in the liquid crystal cell are accumulated on the one substrate 1 side of the liquid crystal layer 5.

  As shown in FIG. 1D, even when the voltages of all the electrodes are turned off, the ionic impurities remain accumulated in the vicinity of the alignment film layer 3, and the liquid crystal molecules have a slight amount. A burn-in phenomenon is observed in order to maintain a state where an electric field is applied.

  In order to solve the problem that this burn-in phenomenon appears, it is effective to reduce the amount of ionic impurities in the liquid crystal cell.

Here, the ionic impurity penetration route from the material into the liquid crystal cell will be described.
For example, as a peripheral material, a sealing agent can be used. In recent years, a photocurable sealing agent or a photocurable thermosetting combined type sealing agent is used as a sealing material.
In general, an acrylic resin or an epoxy resin is used. In order to polymerize these resins, a radical photopolymerization initiator or a cationic photopolymerization initiator is used. If the reaction of these polymerizing agents is insufficient, they are converted into ionic impurities. Since the liquid crystal material and the sealing material are in contact with each other, the ionic impurities in the liquid crystal cell increase dramatically.

Further, in the liquid crystal material, impurities remaining at the time of synthesis are increased. In general, as the dielectric anisotropy Δε of the liquid crystal material increases, the polarity of the liquid crystal increases and ionic impurities are easily dissolved in the liquid crystal, and the image quality and reliability are becoming strict.
There are various routes for intruding ionic impurities from the outside. For example, when the alignment film is formed by a technique such as spin coating or vapor deposition, the film is formed up to the edge of the substrate. Moisture and ionic impurities enter the liquid crystal through the interface, and the occurrence of problems becomes significant.
Further, there may be a case where surrounding ionic impurities are dissolved during storage of the liquid crystal material or in the injection process.

In the projection type LCD used for the projector, the seriousness of these problems is more remarkable. Since the projection is magnified, image quality abnormality is conspicuous, and the amount of light incident on the panel is much larger than that of the direct-view type, so that the panel becomes high temperature and deterioration due to mixing of a small amount of ionic impurities tends to be visible.
In addition to water and temperature, resistance to light is required, and minute contamination can be a major issue. In particular, various problems caused by ionic impurities as well as deterioration of burn-in by light irradiation are in a severer direction, particularly in a projection type LCD.

  The present invention can reduce the amount of ionic impurities in a liquid crystal cell, suppress the occurrence of image sticking phenomenon, etc., and thus obtain a higher quality image and projection type liquid crystal display. To provide an apparatus.

  A first aspect of the present invention is a liquid crystal display element in which a liquid crystal layer is sandwiched between a pair of substrates bonded with a sealing material so that the alignment films face each other with a predetermined gap, and 100 parts by weight of the base material of the sealing agent On the other hand, the content of the radical photopolymerization initiator is less than 0.05% by weight.

  Preferably, the liquid crystal display element is an active matrix liquid crystal display element that performs frame inversion driving in which a voltage applied to each pixel electrode is inverted with the same polarity for each frame.

  A projection-type liquid crystal display device according to a second aspect of the present invention includes a light source, at least one liquid crystal display element, a condensing optical system for guiding light emitted from the light source to the liquid crystal display element, and the liquid crystal display element. A projection optical system that magnifies and projects the light modulated by the liquid crystal display element, and the liquid crystal display element has a liquid crystal layer between a pair of substrates bonded with a sealing material so that the alignment films face each other with a predetermined gap. The content of the radical photopolymerization initiator is less than 0.05% by weight with respect to 100 parts by weight of the base material of the sealing agent.

  According to the present invention, the amount of ionic impurities in the liquid crystal cell can be reduced, the occurrence of image sticking and the like can be suppressed, and as a result, a higher quality image can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In this embodiment, after explaining the characteristic configuration and function of the active matrix liquid crystal display element, the schematic configuration and function of the projection type liquid crystal display device, which is a suitable electronic apparatus to which the liquid crystal display element is applied, will be described. To do.

  FIG. 2 is a cross-sectional view showing a schematic configuration of the active matrix liquid crystal display element according to the present embodiment.

As shown in FIG. 2, the liquid crystal display element 10 according to the present embodiment includes a TFT array substrate 11 and a transparent counter substrate 12 disposed to face the TFT array substrate 11.
For example, the TFT array substrate 11 is formed of a quartz substrate in the case of a transmission type, and a substrate of silicon material in the case of a reflection type. The counter substrate 12 is formed of, for example, a glass substrate or a quartz substrate. In the case of a transmission type, the TFT array substrate 11 is provided with a pixel electrode 13.
The pixel electrode 13 is formed of a transparent conductive thin film such as an ITO film (indium tin oxide film). In the case of the reflection type, for example, a reflection electrode made of a metal material is used as the pixel electrode 13. As the metal material, aluminum having a high reflectance in the visible range is generally used. More specifically, an aluminum metal film added with several wt% of copper or silicon is generally used. In addition, for example, platinum, silver, gold, tungsten, titanium, or the like can be used. The counter substrate 12 is provided with the above-described entire ITO film 14 on the front surface.
An alignment film (not shown) for aligning the liquid crystal in a predetermined direction is formed on the TFT array substrate 11 and the counter substrate 12, and a pair of layers bonded together with a sealing material 15 so that the alignment films face each other with a predetermined gap. A vertically aligned liquid crystal layer 16 is sandwiched (encapsulated) between the substrates.

  FIG. 3 is a diagram showing an arrangement example of the active matrix type liquid crystal display element according to the present embodiment on the array substrate (liquid crystal panel unit).

As shown in FIG. 3, the liquid crystal display element 10A includes a pixel display area 21 in which pixels are arranged in an array, a horizontal transfer circuit 22, vertical transfer circuits 23-1 and 23-2, a precharge circuit 24, and a level converter. The circuit 25 is formed.
In the pixel display area 21, a plurality of data lines 26 and a plurality of scanning lines (gate wirings) 27 are wired in a grid pattern. One end of each data line 26 is connected to the horizontal transfer circuit 22, and the other end is precharged. Connected to the circuit 24, the end of each scanning line 27 is connected to the vertical transfer circuits 23-1, 23-2.

A plurality of pixels PX that are formed in a matrix that forms the pixel display region 21 of the liquid crystal display element 10A are provided with a pixel switching transistor 28 that controls switching, a liquid crystal 29, and an auxiliary capacitor (storage capacitor) 30.
A data line 26 to which a pixel signal is supplied is electrically connected to the source of the transistor 28 and supplies a pixel signal to be written. In addition, the scanning line 27 is electrically connected to the gate of the transistor 28, and the scanning signal is applied to the scanning line 27 in a pulse manner at a predetermined timing.
The pixel electrode 13 is electrically connected to the drain of the transistor 28. By turning on the transistor 28, which is a switching element, for a certain period, the pixel signal supplied from the data line 26 is transmitted at a predetermined timing. Write pixel signal.

A pixel signal of a predetermined level written to the liquid crystal 29 via the pixel electrode 13 is held for a certain period with the counter electrode formed on the counter substrate 12. The liquid crystal 29 modulates light and enables gradation display by changing the orientation and order of the molecular assembly according to the applied voltage level.
In the case of normally white display, incident light can pass through the liquid crystal portion according to the applied voltage, and light having a contrast corresponding to the pixel signal is emitted from the liquid crystal display element as a whole.
Here, in order to prevent the held pixel signal from leaking, an auxiliary capacitor (storage capacitor) 30 is added in parallel with the liquid crystal capacitor formed between the pixel electrode and the counter electrode. Thereby, the retention characteristics are further improved, and a liquid crystal display element with a high contrast ratio can be realized.
In addition, in order to form such a storage capacitor (storage capacitor) 30, a resistance common wiring 31 is provided.

  The liquid crystal display element 10 of the present embodiment is configured as, for example, an active matrix liquid crystal display element that performs frame inversion driving that inverts the voltage applied to each pixel electrode with the same polarity for each frame.

  FIG. 4 is a cross-sectional view showing a specific configuration example on the TFT array substrate side of the active matrix type liquid crystal display element according to the present embodiment.

The liquid crystal display element 10A includes a TFT array substrate 11, a first light shielding film 32 formed on the TFT array substrate 11, and a first interlayer film 33 formed on the TFT array substrate 11 and the first light shielding film 32. A polycrystalline Si film (p-Si) 34 formed on the first interlayer film 33, a gate insulating film 35 formed on the polycrystalline Si film (p-Si) 34, and a gate insulating film 35 The gate electrode 36 formed thereon, the first interlayer film 33, the gate insulating film 35, the second interlayer film 37 formed on the gate electrode 36, and the first contact formed on the second interlayer film 37 38, the first wiring film 39 formed including the inside of the first contact 38, the third interlayer film 40 formed on the second interlayer film 37 and the first wiring film 40, and the third interlayer film 40 The formed second contact 41 and the third layer including the inside of the second contact 41 Conductive second light-shielding film 42 formed on film 40, fourth interlayer film 43 formed on third interlayer film 40 and second light-shielding film 42, and fourth interlayer film 43. A third contact 44, a transparent electrode 45 selectively formed on the fourth interlayer film 43 including the inside of the third contact 44, and a columnar spacer 46 formed on the transparent electrode 45 and the fourth interlayer film 43, Have
Although not shown in FIG. 4, an alignment film (not shown) for aligning liquid crystals in a predetermined direction is formed on the TFT array substrate 11 and the counter substrate 12 as described with reference to FIG. The vertical alignment liquid crystal layer 16 is sandwiched (encapsulated) between a pair of substrates bonded with a sealant 15 so that the alignment films face each other with a predetermined gap.

  The liquid crystal display element 10 (10A) according to the present embodiment having the above-described configuration can reduce the amount of ionic impurities in the liquid crystal cell, can suppress the occurrence of a burn-in phenomenon, and thus higher quality. In order to obtain a good image quality, it has a characteristic configuration as shown below.

The liquid crystal display element 10 is basically a frame in which electrodes 13 and 14 are formed on opposing surfaces of each substrate to form matrix-like pixels, and the voltage applied to each pixel electrode is inverted with the same polarity for each frame. An active matrix type liquid crystal display element that performs inversion driving, an alignment film for aligning liquid crystals in a predetermined direction is formed on two substrates 11 and 12, and the two substrates 11 and 12 are predetermined. A vertical alignment liquid crystal layer 16 is sandwiched between a pair of substrates 11 and 12 which are bonded to each other with a sealant 15 so as to be opposed to each other with a gap therebetween.
The liquid crystal display element 10 has the following characteristic configuration.

In the liquid crystal display element 10, the liquid crystal material forming the liquid crystal layer 16 has a retardation Δnd range that can be given as the product of the refractive index anisotropy Δn and the cell gap d smaller than 0.55 μm, and a measurement temperature of 70 ° C. The range of the dielectric anisotropy Δε at −4.5 is less than 0.
More preferably, the range of Δnd of the liquid crystal material in the liquid crystal display element 10 is 0.34 μm to 0.55 μm, and the range of the dielectric anisotropy Δε at a measurement temperature of 70 ° C. is −4.5 to −2. It is.
The content of the photo radical polymerization initiator is less than 0.05% by weight with respect to 100 parts by weight of the base material of the sealing agent.
Further, it is possible to adopt a configuration in which any two of the above three characteristic portions are combined or a configuration in which three are combined.
Furthermore, the liquid crystal panel is a transmissive liquid crystal panel, and the pixel pitch is 20 μm or less. In addition, an inorganic alignment film is used as the alignment film.
The above characteristic configuration will be further described in detail.

As countermeasures for suppressing defects such as image sticking due to ionic impurities in the liquid crystal cell, there are countermeasures such as making it difficult to dissolve even if ionic impurities are present, or reducing mixing of ionic impurities.
In the former, it is effective to reduce the dielectric anisotropy Δε of the liquid crystal material and to reduce the polarity of the liquid crystal, and in the latter, it is effective to remove a substance causing the generation of impurities.

First, the dielectric anisotropy Δε of the liquid crystal is controlled to make it difficult to dissolve even in the presence of ionic impurities.
When the dielectric anisotropy Δε is smaller than −4, particularly when it is smaller than −4.5, the polarity becomes high, and various reliability problems including burn-in become remarkable. Details are given in the examples.
On the other hand, when the dielectric anisotropy Δε is 0, the function as a liquid crystal is lost. When the dielectric anisotropy Δε is larger than −2, the threshold voltage Vth is high although it is a good direction for the presented problem. May be out of the practical range.

  The expression of the threshold voltage Vth of the vertical alignment greatly depends on the refractive index anisotropy Δε as shown below.

5, FIG. 6 and FIG. 7 are diagrams showing voltage versus transmittance characteristic curves when the conditions of dielectric anisotropy Δε and K33 are changed. FIG. 5 shows the case where K33 is 10. FIG. 6 shows a voltage vs. transmittance characteristic curve, FIG. 6 shows a voltage vs. transmittance characteristic curve when K33 is 15, and FIG. 7 shows a voltage vs. transmittance characteristic curve when K33 is 20.
5 to 7, the horizontal axis represents voltage, and the vertical axis represents relative transmittance. 5-7, the curve indicated by A is the characteristic when Δε is −1, the curve indicated by B is the characteristic when Δε is −2, and the curve indicated by C is when Δε is −3. The curves indicated by D indicate the characteristics when Δε is −4.

FIG. 8 is a graph showing the relationship between the dielectric anisotropy Δε and the saturation voltage at which the transmittance becomes 100%. In FIG. 8, the horizontal axis indicates the refractive index anisotropy Δε, and the vertical axis indicates the saturation voltage Vsat. In FIG. 8, the curve indicated by A indicates the characteristics when K33 is 10, the curve indicated by B indicates the characteristics when K33 is 15, and the curve indicated by C indicates the characteristics when K33 is 20. ing.
5 to 8 show characteristics when the cell gap is 3.8 μm and the pretilt angle is 80 °.

In FIG. 5 to FIG. 8, the range of K33 that a general vertical alignment type liquid crystal can take is 10 to 20. Other physical property values and cell parameters were the same as shown in the figure.
Of particular note is the saturation voltage of the device (hereinafter Vsat: the voltage at which the transmittance is 100%), as shown in FIG. FIG. 8 shows the relationship between the refractive index anisotropy Δε and the saturation voltage Vsat in the range of K33 from 10 to 20.
As shown in FIG. 8, when Δε becomes larger than −2, the saturation voltage Vsat becomes 5 V or more, and the drive voltage tends to increase.
Therefore, it is desirable that the upper limit of the refractive index anisotropy Δε suitable for a practical device is −2.

Next, as one of the countermeasures for removing the causative substances of the generation of impurities, attention is paid to the polymerization initiator for the seal, which will be discussed below.
Since the polymerization initiator generates a small amount of residue after curing, it is assumed that the residue dissolves in the liquid crystal during use of the liquid crystal display element, and ionic impurities increase, causing display defects such as image sticking and unevenness. It is to be done.

There are two types of seal polymerization initiators: radical polymerization initiators and cationic polymerization initiators.
As the cationic polymerization initiator, for example, a compound disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2005-306949) is used.
Examples of the radical polymerization initiator include Patent Document 2 (Japanese Patent Laid-Open No. 2003-119248), Patent Document 3 (Japanese Patent Laid-Open No. 2003-119249), Patent Document 4 (Japanese Patent Laid-Open No. 2006-22228), and Patent Document. 1 (Japanese Patent Laid-Open No. 2005-306949) is used.
In particular, in Patent Document 4 (Japanese Patent Laid-Open No. 2006-22228), the amount of radical polymerization initiator added is specified in the range of 0.1-1 wt% or more.
However, as will be described in detail in Examples, analysis of a panel in which display defects such as image sticking occurred was analyzed, and it was revealed that a large part of the contribution to the defects was a radical polymerization initiator. Furthermore, it was also clarified that there is no problem if it is less than 0.05% by weight.
It was also clarified that one cationic polymerization initiator hardly contributes to the failure, and if a certain amount is added, the polymerization of the resin proceeds and there is no problem in the adhesion function as a seal.

Next, the range of retardation Δnd specified in the present embodiment will be described.
In the case of a normally black (NB) mode in which the polarizing plate PL and the analyzer plate DL are arranged orthogonally and display black when not lit, the retardation (Δnd) for obtaining the maximum transmittance is defined by the following theoretical formula: Yes.

[Equation 2]
T = sin ² (2Θ) sin ² (πΔnd / λ)

Here, Θ is an angle formed by polarized light and the major axis, and the first term is maximum when Θ = 45 °. The second term is maximum when Δnd = (2n−1) × (λ / 2).
That is, it is Δnd = λ / 2 that can obtain the maximum transmittance.

  The vertical alignment liquid crystal of this device (liquid crystal display element) is aligned with the liquid crystal molecular major axis in the direction perpendicular to the substrate when the applied voltage is zero, and is tilted with respect to the in-plane direction when a voltage is applied. Is to be changed. If the direction in which the liquid crystal molecules are tilted at the time of driving is not uniform, display defects such as unevenness may occur. In order to avoid this, it is necessary to apply a slight pretilt in a certain direction in advance. When these physical properties such as pretilt and refractive index anisotropy Δε are taken into consideration, Δnd for obtaining the maximum transmittance differs from the calculated value due to the interaction of liquid crystal molecules.

FIG. 9 is a diagram illustrating a Δnd vs. transmittance characteristic curve for green light having a wavelength of 550 nm when the conditions of Δε and K33 when the applied voltage is 5 V are changed.
In FIG. 9, the horizontal axis indicates Δnd, and the vertical axis indicates the transmittance. In FIG. 9, the curve indicated by A is the characteristic when 33 is 10 and Δε is −2.0, the curve indicated by B is the characteristic when K33 is 10 and Δε is −4.0, and C The curve shown is a characteristic when K33 is 10 and Δε is −4.5, the curve indicated by D is a characteristic when 33 is 20 and Δε is −2.0, and the curve indicated by E is a curve when K33 is 20 and Δε , And the curve indicated by F shows the characteristic when K33 is 20 and Δε is −4.5.

FIG. 10 is a diagram showing the relationship between dielectric anisotropy Δε and retardation Δnd that can be derived from the characteristics of FIG.
In FIG. 10, the horizontal axis represents the dielectric anisotropy Δε, and the vertical axis represents the retardation Δnd. In FIG. 10, the curve indicated by A indicates the characteristic when K33 is 10, and the curve indicated by B indicates the characteristic when K33 is 20.

  In this case, calculation was performed for 10 to 20 as the range of K33 that a general vertical alignment type liquid crystal can take. The dielectric anisotropy Δε was set to −2, −4, and −4.5. Other physical property values and cell parameters were the same as shown in the figure (signal voltage Vsig = 5V). In this calculation, 2DMASTER was used.

  From FIG. 9, the following conditional expressions can be derived when K33 is 10 and K33 is 20.

  From this result, in the range of −4.5 ≦ Δε <0, the range of Δnd for obtaining the maximum transmittance is Δnd ≦ 0.55 μm, and desirably in the range of −4.0 ≦ Δε ≦ −2.0. The range of Δnd for obtaining the maximum transmittance was specified as 0.34 μm ≦ Δnd ≦ 0.55 μm.

Along with the miniaturization of the projection display device, the liquid crystal display element is also miniaturized, the substrate size is 22.9 mm (diagonal 0.9 inch) XGA type, and the pixel (pixel) pitch is 20 μm or less. Progressing.
Therefore, it is in a very severe direction with respect to the alignment disturbance due to the reverse tilt domain due to the transverse electric field.
As a countermeasure, it is also effective to narrow the gap, that is, to thin the cell gap, to strengthen the vertical electric field between the TFT array substrate and the counter substrate, and to prevent the influence of the horizontal electric field. For narrowing the gap, it is very effective for gap control to create a spacer selectively in the light shielding part.

  FIG. 11 is a diagram illustrating the relationship between the pixel pitch, the alignment disorder, and the cell gap.

  In FIG. 11, the plot points indicated by black squares indicate the relationship between the pitch and the orientation disturbance when the cell gap d is 4.5 μm, and the plot points indicated by white squares indicate the pitch and orientation when the cell gap d is 4.2 μm. The plot points indicated by black triangles indicate the relationship between the disturbance and the pitch when the cell gap d is 4.0 μm, and the plot points indicated by black circles indicate the pitch when the cell gap d is 3.7 μm. The plot points indicated by white triangles indicate the relationship between the pitch and the alignment disturbance when the cell gap d is 3.5 μm, and the plot points indicated by black circles indicate the relationship between the alignment disturbance and the alignment disorder when the cell gap d is 2.5 μm. The relationship between the pitch and the disorder of orientation is shown.

As can be seen from FIG. 11, the cell gap d is preferably 4.0 μm or less so as not to cause alignment disorder at a pitch of 20 μm.
In this case, the range of the refractive index anisotropy Δn at which the maximum transmittance can be obtained is 0.085 or more from the formula [Δn ≧ 0.34 μm ÷ 4.0 μm] from Δnd ≧ 0.34 μm, which is the characteristic described above. Is desirable.

In defining physical property values, as shown in Patent Document 5 (Japanese Patent Laid-Open No. 2001-255562), Δε is from −7.0 to − for the purpose of reducing alignment disturbance such as disclination. It is specified in the range of 4.3.
However, for the reasons described above, even if disclination is reduced, display defects including burn-in occur.
In the present embodiment, it is possible to provide a liquid crystal display element that can solve display defects such as disclination and burn-in.

In this embodiment, as described above, the alignment film material is an inorganic alignment film.
Projection-type LCDs used in projectors are prone to image quality anomalies due to enlargement projection, and the amount of light incident on the panel is much higher than direct-view type, so the panel becomes hot and deteriorates due to the presence of a small amount of ionic impurities Tends to be visible. This is because resistance to light is important in addition to water and temperature.
Examples of the inorganic alignment film include silicon formed by vapor deposition, but it is possible to use almost all substances that can be formed by vapor deposition, such as germanium and other group IV elements or mixtures or compounds. Conceivable.
In addition, a material having a siloxy acid skeleton formed by printing, spin coating, or an ink jet method may be used.

  Examples of the present invention are shown below.

<Example>
First, a method for manufacturing an active matrix liquid crystal display element according to this embodiment will be described with reference to FIG.

A high melting point metal (WSi in this embodiment) was formed on the TFT array substrate 11 made of quartz as the first light shielding film 32.
Thereafter, SiO ₂ was laminated as the first interlayer film 33, a polycrystalline Si film (p-Si) 34 was formed by CVD, and a pattern was formed by etching.
Thereafter, a gate insulating film 35 was formed, a polycrystalline Si film (p-Si) was formed as the gate electrode 36, and a pattern was formed by etching.
Thereafter, SiO ₂ was laminated as the second interlayer film 37, and the first contact 38 was formed as the source and drain electrodes.
A metal material (Al in the present embodiment) was formed as the first wiring film 39 by film formation such as sputtering, and patterning was performed by etching.
Thereafter, SiO ₂ was laminated as the third interlayer film 40 to form the second contact 41, and then a metal film (Ti in this embodiment) was formed as the second light shielding film.
SiO ₂ was laminated as the fourth interlayer film 43, the third contact 44 was formed, and ITO was patterned as the transparent electrode 45 by etching.
Next, a transparent resist layer to be the columnar spacer 46 was formed.
After applying PMER (manufactured by Tokyo Ohka Kogyo Co., Ltd.) to a thickness of 3 μm as a photoresist on the substrate by a spin coating method, an exposure treatment by ultraviolet irradiation is performed using a photomask, followed by development and baking. As a result, the columnar spacer 46 is formed. The columnar spacer 46 is disposed at a desired position between adjacent pixel electrodes.
Next, the fabricated TFT array substrate 11 and counter substrate 12 are washed.

Next, an alignment film is formed on each substrate.
An inorganic alignment film was used as the alignment film material. Typically, silicon or the like formed by vapor deposition can be mentioned, but it is considered that almost all substances that can be formed by vapor deposition can be used as a simple substance or a mixture or compound of group IV elements such as germanium.
In addition, a material having a siloxy acid skeleton formed by printing, spin coating, or an ink jet method may be used. Of course, not only inorganic materials but also organic materials such as polyimide may be used.
An alignment film was formed on each substrate. Each substrate was introduced into a vapor deposition apparatus, and each was formed by obliquely vapor-depositing SiO ₂ as an alignment film. The film thickness was applied to a thickness of about 50 nm.
A seal pattern was then formed.
Table 1 shows the sealant used in this example.

  As the acrylate-based oligomer, for example, 1% of ALBIFLEX 712 (hereinafter referred to as AF712, manufactured by Hanse Chemie), which is a commercially available product as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2005-306949), was used. In addition, regarding this commercial item, it is not limited.

  As the epoxy-based oligomer, 99% of bisphenol F-type epoxy resin (Epicron 830S, manufactured by Dainippon Ink & Chemicals, Inc.) was used. Such a commercial product may be used.

  As the photo radical initiator, 0.1% of Irgacure 184 manufactured by Ciba Specialty Chemicals was used. As shown in paragraphs [0032] and [0033] of Patent Document 1 (Japanese Patent Laid-Open No. 2005-306949). Any material can be used.

  Further, 1% of Wako Pure Chemicals PI-113 was used as the photocation initiator, but a material as shown in paragraph [0031] of Patent Document 1 (Japanese Patent Laid-Open No. 2005-306949) may be used.

  The liquid crystal material used for the liquid crystal layer is a vertical liquid crystal material having a negative dielectric anisotropy Δε, Δε = −5, a refractive index anisotropy Δn of 0.13, and a cell gap d which is the thickness of the liquid crystal layer. The liquid crystal display element 10 was produced by setting the thickness to 3.5 μm.

  Comparative Examples 1 to 3 are shown below.

<Comparative Example 1> ... Reduction of Δε of Liquid Crystal Material The liquid crystal display element of the present invention was produced by changing the liquid crystal material only in the same manner as described above until the seal formation.
The liquid crystal material has a dielectric anisotropy Δε of -4.7, -4.5, -4, -3.5, a refractive index anisotropy Δn of 0.13, and a thickness of the liquid crystal layer. The cell gap d is set to 3.5 μm, and a liquid crystal display element that can be imaged by packaging the outer packaging with a flexible film or the like is manufactured, the following evaluation is performed, and compared with a conventional example having a general configuration It was decided to. The results are shown in Table 1 and FIG. FIG. 12 shows the relationship between | Δε | and flicker.

[Evaluation]
(Burn)
The liquid crystal display element of the present example was put in a projection type display device at 70 ° C., and a pine pattern was held for 8 hours.
Thereafter, the image quality was evaluated by switching to a raster pattern. Ranks are marked with a one-pine pattern clearly remaining (×), with some remaining triangular (△), almost invisible circle (○), and completely invisible Circle (◎).

(Flicker value)
Measurement was performed using a spectrum analyzer.
The flicker value acceptance criteria are shown in FIG. Looking at the burn-in image, a questionnaire of NG-OK was conducted on 50 people.
As a result, it was judged as NG when the flicker value was 14 dB or more.
In other words, as can be seen from FIG. 12, the seizure of 14 dB or less can be controlled by designing so that | Δε | <4.5 at 70 ° C.

(Light irradiation test)
The liquid crystal display element of the present invention was placed in a 90 ° C. light irradiation test apparatus equipped with a 250 W UHP lamp, and the appearance of peripheral unevenness after a certain time was observed.
Flickering (×) if the entire screen is uneven or spotted, triangles (△) if you can see part, circles (○) if you can hardly see anything, double circles if there is no abnormality (◎) ).
When the dielectric anisotropy Δε was −4.5 or less, the burn-in, flicker value, and light irradiation test result were very good.
Thus, by using the liquid crystal display element of the present invention, a more reliable high quality liquid crystal display element could be obtained.

<Comparative example 2> ... Reduction of radical initiator Before the seal was formed, it was performed in the same manner as described above, and the conditions of the seal material were changed.
The liquid crystal display element of the present invention was prepared under the conditions of 0.08%, 0.06%, 0.05% and no radical initiator.
For the liquid crystal material, the dielectric anisotropy Δε is −5, the refractive index anisotropy Δn is 0.13, the cell gap d, which is the thickness of the liquid crystal layer, is set to 3.5 μm, and the package is packaged with flexible or the like. A liquid crystal display element that can be imaged in this manner was created, the following evaluation was performed, and comparison was made with a conventional example having a general configuration. The results are shown in Table 1 and FIG. FIG. 14 shows the relationship between the amount of radical initiator and flicker.

[Evaluation]
(Burn)
The liquid crystal display element of the present example was put in a projection type display device at 70 ° C., and a pine pattern was held for 8 hours.
Thereafter, the image quality was evaluated by switching to a raster pattern. Ranks are marked with a one-pine pattern clearly remaining (×), with some remaining triangular (△), almost invisible circle (○), and completely invisible Circle (◎).

(Flicker value)
Measurement was performed using a spectrum analyzer.
In addition, NG-OK questionnaire was conducted on 50 people by looking at the burn-in image.
As a result, it was judged as NG when the flicker value was 14 dB or more.
As can be seen from FIG. 14, in the liquid crystal with | Δε | = 5.0 at 70 ° C., when the amount of radical initiator is reduced, the image sticking level is reduced.

(Light irradiation test)
The liquid crystal display element of the present invention was placed in a 90 ° C. light irradiation test apparatus equipped with a 250 W UHP lamp, and the appearance of peripheral unevenness after a certain time was observed.
Flickering (×) if the entire screen is uneven or spotted, triangles (△) if you can see part, circles (○) if you can hardly see anything, double circles if there is no abnormality (◎) ).
When the dielectric anisotropy Δε was −4.5 or less, the burn-in, flicker value, and light irradiation test result were very good.

(Adhesive strength)
The sealant of the example was applied to a slide glass in a fixed amount, pressure-cured at 100 mW / cm ² for 60 seconds, and then baked in an oven at 130 ° C. for 1 hour, and the strength was measured using a tension gauge. The relative value when the conventional example which has a general structure is set to 1 was shown.
Thereafter, a storage test was conducted at 60 ° C. and 90% for 500 hours, and the strength was measured again.

It was found that when the radical initiator was 0.05 wt% or less, the burn-in, flicker value, and light irradiation test results were very good.
There was no risk of lowering adhesive strength due to reducing radical initiator. In particular, there was no problem even when the radical initiator was zero.
It has been found that if a certain amount of cationic initiator is introduced, there is a sufficient adhesive effect.
Thus, by using the liquid crystal display element of the present invention, a more reliable high quality liquid crystal display element could be obtained.

<Comparative example 3> ... Reduction of synergistic effect Δε Reduction of radical initiator Before the seal was formed, the same procedure as described above was performed, and the conditions of the seal material were changed.
Conditions without radical initiator, the liquid crystal material has a dielectric anisotropy Δε of −3.5, a refractive index anisotropy Δn of 0.13, and a cell gap d, which is the thickness of the liquid crystal layer, of 3.5 μm. A liquid crystal display element that can be set and printed with a package or the like to create an image can be created, evaluated as follows, and compared with a conventional example having a general configuration. The results are shown in Table 1 and FIG. FIG. 15 shows the relationship between | Δε | and flicker.

[Evaluation]
(Burn)
The liquid crystal display element of the present example was put in a projection type display device at 70 ° C., and a pine pattern was held for 8 hours.
Thereafter, the image quality was evaluated by switching to a raster pattern. Ranks are marked with a one-pine pattern clearly remaining (×), with some remaining triangular (△), almost invisible circle (○), and completely invisible Circle (◎).

(Flicker value)
Measurement was performed using a spectrum analyzer.
In addition, NG-OK questionnaire was conducted on 50 people by looking at the burn-in image.
As a result, it was judged as NG when the flicker value was 14 dB or more.

(Light irradiation test)
The liquid crystal display element of the present invention was placed in a 90 ° C. light irradiation test apparatus equipped with a 250 W UHP lamp, and the appearance of peripheral unevenness after a certain time was observed.
Flickering (×) if the entire screen is uneven or spotted, triangles (△) if you can see part, circles (○) if you can hardly see anything, double circles if there is no abnormality (◎) ).
When the dielectric anisotropy Δε was −4.5 or less, the burn-in, flicker value, and light irradiation test result were very good.
(Adhesive strength)
The sealant of the example was applied to a slide glass in a fixed amount, pressure-cured at 100 mW / cm ² for 60 seconds, and then baked in an oven at 130 ° C. for 1 hour, and the strength was measured using a tension gauge. The relative values when a general configuration example (conventional example) is 1 are shown.
Thereafter, a storage test was conducted at 60 ° C. and 90% for 500 hours, and the strength was measured again.

By combining the reduction of the radical initiator and the reduction of the dielectric anisotropy Δε, good results could be obtained in all evaluation items.
Thus, by using the liquid crystal display element of the present invention, a more reliable high quality liquid crystal display element could be obtained.

  Next, as an example of an electronic apparatus using the above liquid crystal display element, a configuration of a projection type liquid crystal display device will be described with reference to the schematic configuration diagram of FIG.

As shown in FIG. 16, a projection type liquid crystal display device (liquid crystal projector) 300 is configured by sequentially arranging a light source 301, a transmission type liquid crystal display element 302, and a projection optical system 303 along an optical axis C. Yes.
The light emitted from the lamp 304 constituting the light source 301 is collected by the reflector 305 so that the component radiated rearward is incident on the condenser lens 306. The condenser lens 306 further concentrates the light and guides it to the liquid crystal display element 302 via the incident-side polarizing plate 307.
The guided light is converted into an image by the liquid crystal display element 302 having the function of a shutter or a light valve and the emission by the air polarizing plate 308. The displayed image is enlarged and projected on the screen 310 via the projection optical system 303.
A filter 314 is inserted between the light source 301 and the condenser lens 306, and removes light having an unnecessary wavelength, such as infrared light and ultraviolet light, contained in the light source.

Next, as an example of an electronic apparatus using the liquid crystal display element, a configuration of a projection type liquid crystal display device will be described with reference to FIG.
A projection type liquid crystal display device 500 shown in FIG. 17 is a schematic configuration diagram of an optical system of a projection type liquid crystal device in which three liquid crystal display elements described above are prepared and used as RGB liquid crystal display elements 562R, 562G, and 562B, respectively. Show.

The projection type liquid crystal display device 500 uses a light source device 520 and a uniform illumination optical system 523 as optical systems.
A color separation optical system 524 as color separation means for separating the light beam W emitted from the uniform illumination optical system 523 into red (R), green (G), and blue (B), and each color light beam R, G, B. Three light valves 525R, 525G, and 525B that are modulation means for modulating, a color composition prism 510 that is a color composition means for recombining the modulated color light flux, and the synthesized light flux on the surface of the projection surface 600 And a projection lens unit 506 which is a projection means for enlarging and projecting. Further, a light guide system 527 for guiding the blue light beam B to the corresponding light valve 525B is provided.

  The uniform illumination optical system 523 includes two lens plates 521 and 522 and a reflection mirror 531, and the two lens plates 521 and 522 are arranged so as to be orthogonal to each other with the reflection mirror 531 interposed therebetween. The two lens plates 521 and 522 of the uniform illumination optical system 523 are each provided with a plurality of rectangular lenses arranged in a matrix.

The light beam emitted from the light source device 520 is divided into a plurality of partial light beams by the rectangular lens of the first lens plate 521. These partial light beams are overlapped in the vicinity of the three light valves 525R, 525G, and 525B by the rectangular lens of the second lens plate 522.
Therefore, by using the uniform illumination optical system 523, even when the light source device 520 has a non-uniform illuminance distribution within the cross section of the emitted light beam, the three light valves 525R, 525G, and 525B can be uniformly illuminated. It can be illuminated.
Each color separation optical system 524 includes a blue-green reflecting dichroic mirror 541, a green reflecting dichroic mirror 542, and a reflecting mirror 543.
First, in the blue-green reflecting dichroic mirror 541, the blue light beam B and the green light beam G included in the light beam W are reflected at right angles and travel toward the green reflecting dichroic mirror 542. The red light beam R passes through the blue-green reflecting dichroic mirror 541, is reflected at a right angle by the rear reflecting mirror 543, and is emitted from the emission unit 544 of the red light beam R to the prism unit 510 side.

Next, in the green reflection dichroic mirror 542, only the green light beam G out of the blue light beam B and the green light beam G reflected by the blue-green reflection dichroic mirror 541 is reflected at right angles, and the green light beam G is emitted from the emitting portion 545. Injected to the side of the synthesis optical system. The blue light beam B that has passed through the green reflecting dichroic mirror 542 is emitted from the emitting portion 546 of the blue light beam B to the light guide system 527 side.
Here, the distances from the emission part of the light beam W of the uniform illumination optical system 523 to the emission parts 544, 545, and 546 of each color light beam in the color separation optical system 524 are set to be substantially equal. A condensing lens 551 and a condensing lens 552 are arranged on the exit side of the emission part 544 for the red light beam R and the emission part 545 for the green light beam G of the color separation optical system 524, respectively. Therefore, the red light beam R and the green light beam G emitted from each emitting unit are incident on the condensing lens 551 and the condensing lens 552 and are collimated.

The collimated red light beam R and green light beam G enter the light valve 525R and the light valve 525G, respectively, and are modulated, and image information corresponding to each color light is added.
That is, these liquid crystal display elements are subjected to switching control in accordance with image information by a driving unit (not shown), thereby modulating each color light passing therethrough. On the other hand, the blue light beam B is guided to the corresponding light valve 525B via the light guide system 527, where it is similarly modulated according to the image information.

  The light valves 525R, 525G, and 525B in this example are liquid crystal light valves that further include incident-side polarizing plates 561R, 561G, and 561B and liquid crystal display elements 562R, 562G, and 562B disposed therebetween. .

The light guide system 527 includes a condensing lens 554 disposed on the emission side of the blue light beam B and the emission unit 546, an incident-side reflection mirror 571, an emission-side reflection mirror 572, and an intermediate lens disposed between these reflection mirrors. 573 and a condensing lens 553 arranged on the front side of the light valve 525B.
The blue light beam emitted from the condenser lens 546 is guided to the liquid crystal display element 562B through the light guide system 527 and modulated. The optical path length of each color light beam, that is, the distance from the emitting portion of the light beam W to each of the liquid crystal display elements 562R, 562G, 562B, the blue light beam B is the longest, and therefore the light amount loss of the blue light beam is the largest.

  However, the light loss can be suppressed by interposing the light guide system 527. The color light beams R, G, and B modulated through the light valves 525R, 525G, and 525B are incident on the color combining prism 510 and combined there. The light combined by the color combining prism 510 is enlarged and projected onto the surface of the projection surface 600 at a predetermined position via the projection lens unit 506.

Note that the above-described effects can be obtained when the present invention is applied not only to a projection type liquid crystal display element but also to a reflection type liquid crystal display element, LCOS, or organic EL device.
In addition, a liquid crystal display element with a built-in drive, a liquid crystal display element with an external drive circuit, liquid crystal display elements with various sizes of about 1 to 15 inches diagonal or larger, a simple matrix system, a TFD active matrix The above-described effects can be expected when applied to any type of liquid crystal display element such as a method, a passive matrix driving method, an optical rotation mode, and a birefringence mode.

As described above, according to the present embodiment, the electrodes 13 and 14 are formed on the opposing surfaces of the substrates 11 and 12 to form the matrix-like pixels, and the voltage applied to each pixel electrode for each frame is set. An active matrix liquid crystal display element that performs frame inversion driving to invert with the same polarity, and an alignment film for aligning liquid crystals in a predetermined direction is formed on two substrates 11 and 12, The substrates 11 and 12 are bonded to each other with a sealant 15 so as to face each other with a predetermined gap, and the vertically aligned liquid crystal layer 16 is sandwiched between the pair of substrates 11 and 12 that are bonded to each other to form the liquid crystal layer 16. The liquid crystal material has a retardation Δnd range that can be given as the product of the refractive index anisotropy Δn and the cell gap d smaller than 0.55 μm, and a dielectric anisotropy at a measurement temperature of 70 ° C. Since the range of ε is less than 0 from -4.5, it is possible to obtain the following effects.
High reliability can be achieved by greatly improving reliability. In addition, along with high definition, it is possible to prevent orientation abnormality due to a narrow cell gap due to high refractive index anisotropic liquid crystal, high contrast, and high speed response. In addition, the projection type LCD such as a projector has an advantage that in addition to prolonging the lifetime, it is possible to realize a high brightness by enabling a high lamp irradiation amount, and a high aperture ratio by reducing the panel size or expanding the effective pixel area.

It is a figure which shows an example of the assumption model of generation | occurrence | production of image sticking. It is sectional drawing which shows schematic structure of the active matrix type liquid crystal display element which concerns on this embodiment. It is a figure which shows the example of arrangement | positioning in the array substrate (liquid crystal panel part) of the active matrix type liquid crystal display element which concerns on this embodiment. It is sectional drawing which shows the specific structural example by the side of the TFT array substrate of the active matrix type liquid crystal display element which concerns on this embodiment. It is a figure which shows the voltage versus the transmittance | permeability characteristic curve at the time of changing the conditions of dielectric anisotropy (DELTA) epsilon and K33, Comprising: It is a figure which shows the voltage versus the transmittance | permeability characteristic curve when K33 is 10. It is a figure which shows the voltage versus the transmittance | permeability characteristic curve at the time of changing the conditions of dielectric anisotropy (DELTA) epsilon and K33, Comprising: It is a figure which shows the voltage versus the transmittance | permeability characteristic curve when K33 is 15. It is a figure which shows the voltage versus the transmittance | permeability characteristic curve at the time of changing the conditions of dielectric constant anisotropy (DELTA) epsilon and K33, Comprising: It is a figure which shows the voltage versus the transmittance | permeability characteristic curve when K33 is 20. It is a figure which shows the relationship between dielectric constant anisotropy (DELTA) epsilon and the saturation voltage from which the transmittance | permeability becomes 100%. It is a figure which shows (DELTA) nd versus the transmittance | permeability characteristic curve in the green (Green) color light of wavelength 550nm at the time of changing the conditions of (DELTA) epsilon and K33 when applied voltage = 5V. FIG. 10 is a diagram illustrating a relationship between dielectric anisotropy Δε and retardation Δnd that can be derived from the characteristics of FIG. 9. It is a figure which shows the relationship between pixel pitch, alignment disorder, and a cell gap. It is a figure which shows the relationship between | (DELTA) epsilon | and flicker in the comparative example 1. FIG. It is a figure shown about the acceptance criteria of a flicker value. It is a figure which shows the relationship between the amount of radical initiators, and flicker. It is a figure which shows the relationship between | (DELTA) epsilon | and flicker in the comparative example 3. FIG. It is a schematic block diagram which shows an example of the projection type liquid crystal display device which concerns on this embodiment. It is a block diagram which shows a more specific example of the 3 plate type | mold projection-type liquid crystal display device which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display element, 11 ... TFT array substrate, 12 ... Counter substrate, 13 ... Pixel electrode, 14 ... Counter electrode, 15 ... Sealing material, 16 ... Liquid crystal layer , 46 ... spacer, 21 ... pixel display area, 22 ... horizontal transfer circuit, 23-1, 23-2 ... vertical transfer circuit, 24 ... precharge circuit, 25 ... level Conversion circuit, 26 ... data line, 27 ... scanning line, 28 ... pixel switching transistor, 29 ... liquid crystal, 30 ... auxiliary capacity (storage capacity), 300, 500 ... projection Liquid crystal display device, 301, 520... Light source, 525R, 525G, 525B... Light valve, 303, 506.

Claims (7)

A liquid crystal display element in which a liquid crystal layer is sandwiched between a pair of substrates bonded with a sealing material so that the alignment films face each other with a predetermined gap,
The content of the radical photopolymerization initiator is less than 0.05% by weight with respect to 100 parts by weight of the base material of the sealant. The liquid crystal display element according to claim 1, wherein the liquid crystal display element is an active matrix liquid crystal display element that performs frame inversion driving in which a voltage applied to each pixel electrode is inverted with the same polarity for each frame. The liquid crystal display element according to claim 1, wherein the liquid crystal panel provided with the pixel electrode is a transmissive liquid crystal panel. The liquid crystal display element according to claim 1, wherein a pixel pitch of the liquid crystal display element is 20 μm or less. The liquid crystal display element according to claim 1, wherein an inorganic alignment film is used for the alignment film. A light source;
At least one liquid crystal display element;
A condensing optical system for guiding the light emitted from the light source to the liquid crystal display element;
A projection optical system for enlarging and projecting light modulated by the liquid crystal display element,
The liquid crystal display element is
A liquid crystal layer is sandwiched between a pair of substrates bonded with a sealing material so that the alignment films face each other with a predetermined gap,
The projection type liquid crystal display device, wherein the content of the photo radical polymerization initiator is less than 0.05% by weight with respect to 100 parts by weight of the base material of the sealing agent. The projection liquid crystal display device according to claim 6, wherein the liquid crystal display element is an active matrix liquid crystal display element that performs frame inversion driving that inverts a voltage applied to each pixel electrode with the same polarity for each frame.

Images