JPH0713163A - Manufacture of optical modulating element - Google Patents

Abstract

PURPOSE:To securely actualize a swinging state which is necessary for wobbling, to effectively obtain high resolution, and to reduce dependency on element environment temperature by obtaining an orientating processing direction with good reproducibility at all times and easily and securely orienting liquid crystal in the same direction. CONSTITUTION:When one orientation film 22 is formed, an orienting process is performed in a direction 90 substantially at an angle 6 of 22.5 deg. to a wobbling direction or a direction crossing it at right angles and the orienting process direction 90 deg. of the other orientation film 23 facing said orientation film 22 is placed in mirror image relation with the orienting process direction 90 of the orientation film 22 about the axis Y of the wobbling direction or the axis X crossing it at right angles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to liquid crystal, plasma, EL
The present invention relates to a method of manufacturing a light modulation element suitable for a display having discrete pixels such as (electroluminescence) and a solid-state imaging element represented by a CCD (charge coupled device) having discrete imaging pixels.

[0002]

2. Description of the Related Art When a line-sequential scanning pixel display is carried out by the NTSC system or the like for a display device having a discrete pixel array such as a liquid crystal, plasma, EL or the like in a mosaic pattern, a dot pattern, etc. The luminance signal, which should be a signal, is roughly sampled and the position information in the horizontal direction is lost. If the vertical pixel resolution cannot be implemented by the number of scanning lines, the positional resolution of the luminance signal or the like (that is,
Display resolution) was reduced.

For example, a TFT (T
In the hin-Film-Transistor) -TN (Twisted Nematic) liquid crystal viewfinder, in the NTSC system, one frame (that is, one picture displayed by the viewfinder) is an even scan line and an odd scan line. The frame frequency is 30 Hz (that is, the field frequency is 60 Hz). Since the current TFT viewfinder cannot mount 525 scanning lines of the NTSC system, the method of writing the odd field and the even field in the same pixel is adopted. For this reason, the vertical resolution is currently lower than that of the NTSC principle.

Further, due to the large pixel size and the presence of joints of non-display pixel portions such as a black matrix, a mosaic-like screen having a discrete pixel array is conspicuous, and the texture of the screen is deteriorated.

The above phenomenon similarly occurs in the image pickup by the CCD. That is, since the captured image forming the CCD is discrete, the image information of the subject is sampled at the constituent pixel pitch, which lowers the horizontal and vertical spatial resolution.

Therefore, a method has been proposed in which the wobbling technique is adopted to introduce a pixel shifting element and spatially shift the images of the odd field and the even field to improve the vertical resolution. This is also applied in the horizontal direction, and the horizontal resolution can be improved.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to enable high-speed wobbling (pixel shifting) for a display composed of discrete pixels, a solid-state image pickup device composed of discrete light-receiving pixels, etc. It is an object of the present invention to provide a method capable of reliably manufacturing an optical modulation element that can effectively achieve the following.

[0008]

That is, according to the present invention, a plurality of optically transparent substrates provided with an optically transparent electrode and an alignment film in this order are provided on one side of the electrode and the other of the alignment film. Wobbling is performed so as to be opposed to each other across a predetermined gap, liquid crystal is injected into the gap, and by combining with an optically transparent birefringent medium, the optical axis of incident light is shifted in a predetermined direction. In manufacturing the light modulation element used for, one of the alignment films is formed substantially in the wobbling direction or the direction orthogonal thereto (that is, just 22.5 degrees is, of course, within the allowable range described later). It means that it is enough if it is a value that produces the same effect.) Angle of 22.5 degrees (The allowable range of this angle is 22.5 degrees ± 5)
It is preferable to set the degree. ), And the alignment treatment direction of the other alignment film facing the one alignment film with respect to the alignment treatment direction of the one alignment film is the axis of the wobbling direction or The present invention relates to a method for manufacturing a light modulation element, which has a mirror image relationship with respect to orthogonal axes.

In the method of the present invention, the alignment treatment directions of the alignment films facing each other are antiparallel or parallel to each other, and the alignment film is formed by an inorganic vapor deposition film, an organic vapor deposition film or an organic rubbing film. can do.

In the method of the present invention, as the above liquid crystal, a chiral smectic liquid crystal or the like, particularly a ferroelectric liquid crystal (FLC) is used.
It is suitable for manufacturing a phase modulation optical element for wobbling in which at least one liquid crystal selected from an antiferroelectric liquid crystal (AFLC) and a smectic liquid crystal exhibiting an electroclinic effect is injected.

In particular, at least one of the electrodes facing each other is divided in the wobbling direction, and is used in combination with a birefringent medium in the optical path between the display element and the observation position where the resolution is to be increased. It is desirable to manufacture the device.

It is also desirable to manufacture a phase modulation optical element used in combination with a polarizing plate and a birefringent medium in an optical path between a subject and an image pickup element whose resolution is to be increased.

[0013]

EXAMPLES Examples of the present invention will be described below.

Light Modulating Element (Phase Modulating Optical Element) First, an example of an optical device incorporating a light modulating element (phase modulating optical element) which can be manufactured by the manufacturing method of the present invention is shown in FIG.
39 to 39 will be briefly described.

In this example, the present invention is applied to a liquid crystal optical display device 1, and as shown in FIGS. 14 and 15, liquid crystal displays sequentially arranged in the same optical path along the traveling direction of light. An element (LCD) 2, a ferroelectric liquid crystal element (FLC) 3 as a phase modulation optical element, and a birefringent medium 4 made of a transparent substrate such as a crystal plate are combined. Here, for ease of understanding, each constituent element is shown for a section corresponding to one constituent display pixel 5 of the liquid crystal display element LCD (hereinafter the same).

The pixels 5 of the LCD 2 are composed of a discrete pixel array such as a mosaic as a whole, and the liquid crystal used is TN (twisted nematic) or STN.
(Super twist nematic), SH (super homeotropic), FLC, etc. This LCD
Although not shown, reference numeral 2 has a polarizing plate on the panel itself as is well known, and the output light 6 has a linearly polarized light.

Then, for this linearly polarized light 6, the above F
The wobbling element (picture element shifting element) 7 composed of the LC 3 and the birefringent medium 4 shifts the picture element in the parallel direction or the vertical direction.

To this end, one extraordinary optical axis 8 of the FLC element 3 is arranged so as to be parallel or perpendicular to the polarization plane 9 of the display pixel 5, and further, an equivalently uniaxial optical axis (uniaxial X of the extraordinary optical axis 10 of the transparent substrate 4 having various optical anisotropy)
The projection component on the −Y plane (incident side) is arranged in parallel (Y direction) or perpendicular (X direction) with respect to the polarization plane 9.

The liquid crystal used in the FLC element 3 is capable of high-speed switching at a video rate, and examples thereof include chiral smectic liquid crystal, and the birefringent medium 4 can be a crystal plate or the like. However, as described later, F
Instead of LC, antiferroelectric liquid crystal (AFLC) or smectic liquid crystal exhibiting an electroclinic effect (for example, smectic A) is also effective, and, of course, a birefringent element other than a quartz plate can be used.

Next, the wobbling operation of the display device 1 will be schematically described.

First, as shown in FIG. 18, the ferroelectric liquid crystal element 3 is used.
When the switch state of 1 is the state 1, since the polarization plane 9 of the light 6 emitted from the display element 2 side and the extraordinary optical axis 8 of the ferroelectric liquid crystal element 3 are parallel, the transmitted light 11 maintains the polarization plane. The crystal plate 4 having birefringence is irradiated. Since the crystal plate 4 includes the extraordinary optical axis 10 of the crystal in the plane of incident polarization, the light polarized in the Y-axis direction is refracted in the direction in which the extraordinary optical axis 10 of the crystal plate 4 is tilted, and the air layer is again formed. When it goes out to 12, it becomes parallel to the optical axis, and a deviation from the optical axis of the incident light occurs in the Y direction.

On the other hand, as shown in FIG. 19, the ferroelectric liquid crystal element 3
When the switch state of is the state 2, the polarization plane 9 and the extraordinary optical axis 8
Since the light has an angle of about 45 degrees, the transmitted light 11 rotates in the direction of the extraordinary optical axis and becomes linearly polarized light (Y-axis direction) → elliptically polarized light → circularly polarized light → elliptically polarized light → linearly polarized light (X-axis direction). The polarization plane is changed by 90 degrees from the initial state by changing the inside of the ferroelectric liquid crystal element 3, and the crystal plate 4 is irradiated with the polarized plane. In the crystal plate 4, since the extraordinary optical axis 10 of the crystal is not included in the plane of incident polarization, the light 11 is not refracted but maintains the optical axis as it is, and again exits to the air layer as outgoing light 12.

As described above, the optical axis is shifted depending on the presence or absence of refraction by the quartz plate 4 in the switch state of the FLC 3, that is, in the state 1 and the state 2, and the shift of the optical axis can be used as the operation principle of the pixel shift. it can.

Here, the cone angle of the liquid crystal that determines the switch state in the FLC 3 will be described. In the ferroelectric liquid crystal (the same applies to the anti-ferroelectric liquid crystal), the switching behavior of the liquid crystal director due to the application of the electric field is that liquid crystal molecules follow the South-Goldstone mode described in P150 of "Liquid Crystal Dictionary" (published by Baifukan). Move on a virtual cone. Furthermore, smectic A having an electroclinic effect
The liquid crystal (P145 of the same liquid crystal dictionary) has a cone angle unique to each liquid crystal composition similar to the cone angle even when the soft mode described in P119 of the same liquid crystal dictionary is used.

That is, consider the cone model of the liquid crystal 15 sandwiched between the transparent electrodes 13-14 made of ITO (Indium tin oxide in which indium is doped with tin) as shown in FIG. The opening angle of the cone is called the cone angle θr, and the projection of this cone angle on the glass substrate with the transparent electrode is called the apparent cone angle θ. Optically, the apparent cone angle θ may be considered. Since this cone angle shows temperature dependence as shown below, in order to obtain an effective wobbling effect, for example, even if a cone angle of 45 degrees is obtained at 25 ° C., the cone angle is low on the low temperature side due to the environmental temperature. There is a phenomenon that the cone angle is large and the cone angle is small on the high temperature side.

For example, as shown in Table 1 below and FIG. 21, in an antiparallel cell with a SiO obliquely vapor-deposited alignment film using FLC liquid crystal CS-1014 manufactured by Chisso Petrochemical Co., Ltd.
The apparent cone angle is 45 degrees near ℃, but at 0 ℃
It was as large as 49.6 degrees and dropped to 7 degrees at 55 ℃. Further, as shown in Table 2 below and FIG. 22, F manufactured by Merck & Co., Inc.
In a similar cell using LC liquid crystal ZLI-3774, 25
The apparent cone angle is about 45 degrees at ℃, but on the low temperature side
It increases to 54.8 degrees at 10 ℃.

[0027]

[0028]

As described above, when the apparent cone angle θ, that is, the angle formed by the extraordinary optical axis 8 of the liquid crystal before and after switching deviates from 45 degrees, the ideal rotation of the polarization plane of 90 degrees as described above can be achieved. However, various problems occur.

Further, in order to examine the effect of the cone angle, 25
CS-2003 (cone angle 60 degrees), CS-2002 (cone angle 64 degrees), and CS-2004 (cone angle 88 degrees) manufactured by Chisso Petrochemical Co., Ltd. can be used as liquid crystals having a large cone angle at ° C. These are all Iso-N ^* -SmC.
^* -A composition showing Cryst. And cone angle 65 ~
80 degree composition is CS-2002 (cone angle 64 degree) and C
Prepared by blending S-2004 (88 degree cone angle).

The cone angle is measured by measuring the angle formed by the liquid crystal directors in two switch states. Specifically, the extinction position is observed by observing the liquid crystal cell under a polarizing microscope in which the polarizers are orthogonal to each other. It was calculated from the rotation angle of the stage at (the position where it rotates and becomes dark).

Therefore, as a result of earnest efforts, the present inventor has found that the following combination of optical axes is effective.

Apparent cone angle due to element ambient temperature
Deviates from 45 degrees (eg 45 + γ degrees: where γ is 45>γ>
-45), in the wobbling operation, if the optical axis of the liquid crystal director in one of the switch states is ideally aligned parallel to or orthogonal to the polarization plane of the display element side, the polarization plane of the transmitted light in this switch state is It does not change. In this case, since the plane of polarization is not rotated, 100% of the light is refracted in the direction of the extraordinary optical axis 10 of the crystal plate 4 and is displaced from the optical axis as shown in FIG. 18, for example. At this time, there is almost no component on the Z axis.

In the other switch state, 45+
Since it is γ degrees, when γ is positive, the polarization plane of the transmitted light is 90 °.
If it rotates by more than 90 degrees and γ is negative, the plane of polarization does not rotate by 90 degrees. When the plane of polarization is completely rotated by 90 degrees, the component on the Z axis becomes almost 100% as shown in Fig. 19, but Fig. 23
As shown in, when the rotation of the polarization plane is deviated from the angle of 90 degrees by γ, the component in the Y-axis direction also increases as the polarization component, so that a component shifted in the Y direction is included in addition to the component on the Z axis. Like Therefore, in this case, the effect of shifting the pixels, which should have a high resolution, is reduced.

In particular, it has been found that the cause of reducing the effect of increasing the resolution is due to the leakage component at the time of pixel shifting.

Here, the cone angle of the liquid crystal will be further described with reference to FIGS. If the LCD cone angle is not 45 degrees,
As shown in FIG. 24, light leakage (that is, crosstalk) occurs between the odd field and the even field. As a result, for example, when the odd field is white and the even field is black, fringes are observed with sufficient contrast if wobbling is completely performed, but if there is a leakage component, white becomes dark and black becomes bright, The contrast decreases.
For example, if the original display element has a contrast of 100: 1, and crosstalk between fields is 10%, 100%
The white level is 90.1%, and the 0% white level (black level) is
It becomes 10.9% and becomes 90.1: 10.9 = 8.27: 1, and the contrast is considerably lowered.

That is, since a contrast of 8: 1 or more is necessary for practical use as a display, it is important to suppress crosstalk between fields to about 10% or less (only when the contrast is guaranteed, high resolution is required). The effect of is confirmed).

An optical system for evaluating this crosstalk amount is shown in FIG. This optical system includes a polarization microscope (OPTIPHOTO-POL manufactured by Nikon Corporation) 70,
It consists of a visible spectrophotometer (Otsuka Electronics Co., Ltd. 100) 71, a personal computer and a monitor 72.

The light emitted from the halogen light source 73 is a polarizer 74 / F.
The spectrum can be obtained by passing the light through the LC element 7 / analyzer 75, the quartz fiber 76 and the visible spectroscope 71. Here, the polarizer 74 and the analyzer 75 are installed in parallel, and when the polarization plane is not rotated by the FLC 7, 100% of the light that has passed through the polarizer 74 passes through the analyzer 75 and the spectroscope 71 Will be introduced to. However, if the deviation of the FLC molecular director from the Y axis is ζ and ζ is not zero,
The light from the polarizer 74 undergoes rotation of the plane of polarization. If ζ = 45 degrees and the gap is further adjusted, the polarization plane can be rotated by 90 degrees. As a result, it does not pass through the analyzer 75,
The transmittance becomes 0%.

Here, the rotation characteristics of the plane of polarization when the liquid crystal director was rotated corresponding to the change in the cone angle were evaluated. That is, when the transmittance is 0%, sufficient wobbling can be performed, and when the transmittance is 10%, 10% of the incident light leaks to the field component on the opposite side. Therefore, the actual experimental results are shown below.

26 and 27 show the spectrum change when ζ is changed. Furthermore, for the wavelength of the minimum transmittance, change the transmittance when ζ is changed to the maximum transmittance of 100%.
When plotted as, it looks like Figure 28.

Here, 0 degrees or less is a mirror image relationship at 0 degrees, and 45 degrees or more is a mirror image relationship at 45 degrees. To secure a contrast of 8 or more (that is, the transmittance is 10% or less,
Or 90% or more), ζ needs to be about ± 10 degrees or less, 36 degrees to 54 degrees.

Further, in order to obtain a contrast of 40 or more by the above method, it is necessary that the transmittance is 1.5% or less,
For that purpose, ζ needs to be about ± 5 degrees or less, 41 degrees to 49 degrees. In other words, converting this by the apparent cone angle, θ is 26 in the range where high resolution can be achieved by wobbling.
It has been found that ~ 64 degrees, more preferably 36-54 degrees are required. Obviously, this is the same in the other quadrants shown in FIG.

Therefore, as shown in FIG. 30, in order to improve the deterioration of the resolution when the pixel is shifted, the bisector 16 of the angle formed by the two switch states is the polarization plane of the light from the display element. The angle δ formed with respect to the (Y direction, that is, the wobbling direction) or a line (X direction) orthogonal to the polarization plane is
It turns out that it is ideal that the angle is 22.5 degrees.

By arranging the liquid crystal directors 8 in this way, crosstalk occurs in both switch states, as shown in FIGS. 31 and 32.
It was found that the crosstalk in each switch state is small, and the sum is averaged and smaller than in the case where crosstalk occurs on only one side, so the effect of higher resolution is not diminished. Moreover, by setting the orientation of the director, the influence of the above-mentioned element environmental temperature is reduced, and its temperature dependence is reduced.

Considering the range of the δ axis in the same way as above, when the apparent cone angle θ is 26 degrees or 64 degrees, δ
= 22.5 degrees only, but when the apparent cone angle θ is 45 degrees, the range of δ should be δ = 22.5 ± 10 degrees or less, more preferably δ = 22.5 ± 5 degrees or less. ing.

Here, the range of the cone angle θ, and further, 2
The angle δ formed by the bisector in the switch state with the plane of polarization of the light from the display element or the line orthogonal thereto was clarified from the following wobbling experimental results.

That is, in the study of fixing the shaft on one side, θ = 26 to
In the range of 64 degrees, we were able to increase the resolution from 240 TV lines of the original liquid crystal display element, which should have been increased by the wobbling effect, to 370 TV lines or more. Furthermore, in the range of θ = 36 to 54 degrees, high resolution with little coloring was achieved. As a result of investigating the position of the δ axis in the range of θ = 36 to 54 degrees, it was found that at δ = 22.5 ± 10 degrees, there was almost no coloring and the resolution could be increased to 370 or more. Furthermore, θ = 36-54 degrees, δ = 2
It was visually confirmed that in the range of 2.5 ± 5 degrees, crosstalk between fields is reduced and the contrast ratio between fields is increased, so that the resolution is further increased to 400 lines or more.

The resolution evaluation here is carried out by inputting a video signal from an NTSC resolution evaluation pattern (video signal pattern generator: Sony's MTSG-1000) and observing the resolution of black and white lines. (Hereinafter the same).

Next, FIG. 33 shows a switch state of a concrete combination example of each element constituting the liquid crystal optical device to which the present invention is applicable. The liquid crystal display element 2 to be combined here may be of any type, such as an active matrix TN liquid crystal, an STN liquid crystal display element, a ferroelectric liquid crystal display element, an antiferroelectric liquid crystal display element, or an SH display element. Here, as an example thereof, a combination example with a TN liquid crystal will be shown.

In the normally white TN liquid crystal display device shown in FIG. 34, the light from the light source is transmitted without applying an electric field to the TN liquid crystal. Here, a combination of the backlight 17-polarizing plate 18-TN liquid crystal 2-polarizing plate 19 or reflection plate-polarizing plate 18-TN liquid crystal 2-polarizing plate 19 is used.
Shows the same TN liquid crystal display element as the conventional one.
Needless to say, the TN liquid crystal element 2 and the ferroelectric liquid crystal element 3 are provided with transparent electrodes on both sides thereof.

In this case, as the electric field strength increases, T
The twist of the N liquid crystal 2 is released, and light is gradually leaked through the polarizing plate to realize gradation display, but any transmitted light is polarized by the polarizing plate 19 in front of the ferroelectric liquid crystal element 3 and has the same linear polarization. Therefore, the pixel shifting can be performed according to the above-described operation principle.

The normally black TN liquid crystal display device shown in FIG. 35 is a mode in which light is transmitted while an electric field is applied to the TN liquid crystal, and the twist of the TN liquid crystal 2 gradually increases as the electric field strength decreases. It returns, it gets darker gradually,
Although gradation display is realized, since any transmitted light becomes the same linearly polarized light by the polarizing plate 19 in front of the ferroelectric liquid crystal element 3, the pixel shifting can be performed according to the above-described operation principle.

As described above, in any type of liquid crystal display device, it is clear that the above device can be applied if the light emitted from the display device is substantially linearly polarized light.

Although the above-mentioned example relates to a display element having polarized light, it is of course applicable to a non-polarized display element.

As shown in FIG. 36, when the polarization degree of the light from the display pixel 5 is small, a polarizing plate 19 may be inserted in the optical path connecting the display element 2 and the pixel shifting element 7 for polarization. good. The optical arrangement conditions are the same as in the case of the liquid crystal display element described above.

The non-polarizing display 2 usable here includes a self-luminous display element such as a plasma display or an LED display.

As described above, wobbling using a phase modulation element (ferroelectric liquid crystal, antiferroelectric liquid crystal, or smectic A liquid crystal having an electroclinic effect) 3 including a chiral smectic liquid crystal that can be driven at a video rate. Element 7 is a liquid crystal composed of discrete pixels, plasma, L
Wobbling (picture element shifting) can be performed by arranging it in the optical path connecting the display such as ED and the observer's retina. Here, the phase modulation element 3 has the following [1],
Examples of the birefringent medium include the following [2].

[1] At least two states exist in the switch state of the ferroelectric liquid crystal, antiferroelectric liquid crystal or smectic A liquid crystal having the electroclinic effect, which can be driven at the video rate, and at least two of them exist. A chiral smectic liquid crystal device with an extraordinary optical axis forming an angle of 26 to 64 degrees, which is optically arranged so that the plane of polarization can be rotated.

[2] A transparent substrate that shifts the optical axis depending on the polarization direction of incident light, and specifically, (a) has an equivalent uniaxial extraordinary optical axis component in the wobbling direction. Arranged (b) A device in which the substrate facing surface through which light is transmitted is not parallel, and the apparent extraordinary optical axis is parallel or perpendicular to a plane perpendicular to both planes.

Next, a specific manufacturing method and operating characteristics of the constituent elements (cells) of the element 3 will be described.

[1] Ferroelectric Liquid Crystal Switching Element The cell structure is as shown in FIG. That is, a transparent electrode (eg, 100 Ω / □ ITO) on the transparent glass substrates 20 and 21.
13 and 14 are provided, and on top of that, Si is used as a liquid crystal alignment film.
The oblique vapor deposition films 22 and 23 of O were formed. In the method of forming the SiO oblique deposition film, the substrate was placed vertically above the SiO deposition source in the vacuum deposition apparatus, and the angle between the vertical line and the substrate normal was set to 85 degrees. Then, as described below, according to the method of the present invention, SiO was vacuum-deposited at a substrate temperature of 170 ° C.
Firing was performed at ℃ for 1 hour.

The substrate with an alignment film thus produced was assembled so that the alignment treatment directions were anti-parallel on the opposite surfaces, and glass beads (true thread: diameter) corresponding to the target gap length were used as the spacers. 0.8 to 3.0 μm (manufactured by Catalysis Kasei) 24 was used. Depending on the size of the transparent substrate, the spacer has a sealing material (UV
Curable adhesive (Photorec: Sekisui Chemical Co., Ltd.)
(Manufactured) 25), the gap between the substrates was controlled by, for example, dispersing about 0.3 wt%. When the board area is large, the above-mentioned true thread balls are placed on the board at an average density of 100 / mm ²
After spraying, a gap was formed, a liquid crystal injection hole was secured around the cell, and the cell periphery was bonded with the above sealing material.

After that, a ferroelectric liquid crystal (for example, CS-1014 manufactured by Chisso Corporation) was injected under reduced pressure in a state showing fluidity at an isotropic phase temperature or a chiral nematic phase temperature. After injecting the liquid crystal, the liquid crystal was gradually cooled to remove the liquid crystal on the glass substrate around the injection hole and then sealed with an epoxy adhesive to manufacture a ferroelectric liquid crystal element. The ferroelectric liquid crystal used can be manufactured by Chisso Co., Ltd., Merck Co., Ltd., BDH, or a composition comprising, for example, the following ferroelectric liquid crystal compound or non-chiral liquid crystal, but is not limited thereto. There is no need to limit the phase sequence, and what is necessary is to take a chiral smectic liquid crystal phase in the operating temperature range.

The liquid crystal layer structure of the chiral smectic liquid crystal element used here has an X-ray structure that has a bookshelf structure in antiparallel, a chevron structure in parallel, or a pseudo bookshelf structure in parallel, depending on the combination of the alignment treatment directions. Clarified by analysis.

[0066]

[Chemical 1]

[0067]

[Chemical 2]

[0068]

[Chemical 3]

[0069]

[Chemical 4]

[0070]

[Chemical 5]

Further, other than the chiral smectic liquid crystal, if the switching speed is high, for example, the following antiferroelectric liquid crystal (AFLC) or smectic A phase exhibiting the electroclinic effect can be applied.

<Antiferroelectric Liquid Crystal> The antiferroelectric liquid crystal is C
It was discovered by handani et al. in 1988 and is characterized by the following three points. (1) Utilizes switching between an antiferroelectric state and two stable states of three stable states. (2) A clear threshold value characteristic is exhibited, and a high contrast when driven by multiplex can be obtained. (3) Use positive and negative hysteresis alternately,
Since the occurrence of internal polarization is suppressed, the image sticking phenomenon is unlikely to occur.

The characteristics of this antiferroelectric liquid crystal material are:
Unlike ferroelectric liquid crystals, chiral liquid crystals are the majority of the composition (spontaneous polarization is large, almost 10 times that of ferroelectric liquid crystals), and the substituent for the asymmetric carbon is CH.
₃ group, CF ₃ group, compounds having C ₂ H ₅ group is readily indicates the antiferroelectric, the core structure is expanded. For example, there is CS-4000 manufactured by Chisso Corporation.

<Smectic Liquid Crystal Showing Electroclinic Effect> The electroclinic effect is a phenomenon in which the tilt angle of the orientation vector is induced by an electric field in the smectic A phase composed of chiral molecules when the temperature is constant. . In the smectic A phase, the orientation vector points in the normal direction of the smectic layer and rotates freely around the major axis. However, application of an electric field along the layer inhibits the free rotation, and the polarization P in the electric field direction is Induced.

Assuming that the linear combination of the polarization P and the tilt angle θ is P = kθ, P = (ε⊥ ^* −ε⊥0) ε _O Ε Therefore, θ = (ε⊥ ^* −ε⊥0) ε _O Like Ε / k,
A tilt angle proportional to the applied electric field E is generated. Where ε⊥ ^*
And ε⊥0 are the permittivity of the racemate of the optically active substance, and ε _O is the permittivity of vacuum. From this, the larger the difference in the dielectric constants of the racemic chiral liquid crystals, the greater the electroclinic effect.

Adjustment of retardation by birefringence: The birefringence and phase transition temperature of the ferroelectric liquid crystal used in the FLC element are shown in Table 3 below.

[0077]

In the above wobbling operation, in order to rotate the polarization plane of the liquid crystal by 90 degrees, the phase may be shifted by 180 degrees. Birefringence (n _e -n _o), the following relationship exists between a cell gap d and the phase difference [delta]. δ = 2πd (n _e −n _o ) / λ

Here, it is sufficient to set δ = π. For this purpose, the cell gap d should be set to d = λ / 2 (n _e −n _o ). However, in reality, since the angle α (pretilt angle) formed by the liquid crystal molecules with the substrate is not 0 degree, n _e becomes small and the gap length d must be made longer.

Here, the ordinary _{ray no} is independent of the incident angle and is equal to the refractive index n⊥ in the short axis direction of the liquid crystal molecule. In other words, n _o = n
It is ⊥.

Specifically, n _e is a function of the pretilt angle α,

[Equation 1]

D depends on the pretilt angle α as follows. d = λ / 2 [n _e (α) -n _o]

That is, α can be obtained from the type of the alignment film, and the optimum gap d can be calculated based on the above relational expression. Therefore,
The alignment film can be used regardless of the type of inorganic alignment film such as SiO or organic alignment film such as polyimide, polyamide, polyvinyl alcohol (PVA).

Further, when the pretilt angle α is 90 degrees, the gap length d becomes infinite according to the above equation, so
A pretilt angle of ~ 89 degrees is required. However, since it is difficult to control the pretilt angle beyond 45 degrees, a pretilt angle of 0 to 45 degrees is practically preferable.

As a driving method for these ferroelectric liquid crystal elements, a conventional general FLC driving method can be applied. In Figure 38, 1
An example of drive waveforms of a frame and two fields is shown.

FIG. 38 (A) shows a pulse drive with a reset pulse, which is a method of adding a reset pulse immediately before writing to maintain an electrically neutral condition in the field. Hard to be applied. A in addition to FLC
It can also be used for FLC.

FIG. 38B shows pulse driving without a reset pulse, which is a method for maintaining an electrically neutral condition within one frame. It can be used for AFLC as well as FLC.

FIG. 38 (C) shows a method of maintaining an electrical neutral condition in one frame in the case of square wave driving, in which the DC voltage is applied for a longer time than in pulse driving, but the element isolation If it is highly reliable, it is a highly reliable driving method. FL
In addition to C, it can be used for AFLC and electroclinic smectic A.

High-speed response of FLC: rising (10-90% T) as switching characteristic by the above drive waveform
Both, and the fall (90-10% T), show a high-speed response on the order of μsec, guaranteeing a sufficient response within one field, and the effective pixel shifting effect at the video rate was achieved for the first time. It

Especially in wobbling (picture element shifting),
It is preferable that the response time of rising and falling is 1/3 or less of the field time, and the ratio of rising time and falling time does not exceed twice each other.

In this respect, when a nematic liquid crystal is used,
Even at a high speed, the rise time when an electric field is applied is relatively short, but the fall time when off is long, so switching in the field is not sufficient, and an effective pixel shifting effect cannot be obtained. The twisted nematic pixel shifting element has a minimum rise / fall time of about 15 msec (room temperature) when the transmittance change is 0 to 90%.
2: 1 line interlace scanning method (1/60 second (16.7 ms) per field) is quite difficult to realize, and if the 4: 1 line interlace scanning method is applied with the same number of frames,
It is 1/120 seconds (8.3 ms) per field, and it becomes impossible to follow at all. In this respect, the pixel shifting method using the ferroelectric liquid crystal element is effective because its switching time is shorter than that of the TN liquid crystal. By the way, the rise and fall times of the ferroelectric liquid crystal element are in the order of μsec, and even the slowest one is several ms or less.

Table 4 below shows the response times of various liquid crystals for comparison, and the response speed of the liquid crystals usable in the present invention is extremely fast.

[2] Birefringent transparent substrate that shifts the optical axis depending on the polarization direction of incident light (a) Equivalently uniaxial extraordinary optical axis 10 is on the same plane as the Z axis as shown in FIG. An element that is present at and is not parallel to the axis.

For example, the deviation L of the optical axis of the quartz plate is calculated by the following formula. As shown in FIG. 39, the angle formed by the extraordinary optical axis 10 of the birefringent transparent medium 4 and the optical axis of the wobbling optical system is β, and the thickness of the crystal plate 4 is d. Here, the refractive index n _o of the ordinary light and the refractive index n _e of extraordinary light of the quartz plate 4 are n _e = 1.5533
6, n _o = 1.54425. Here, 0.7 inches, 1
L = 24.5 μm to increase the resolution in the vertical direction of an active matrix TN liquid crystal display with 0.3 million pixels
As values giving the deviation of β = 45 degrees, d = 4.17 mm.

[0095]

[Equation 2]

Here, the range of β effective for expressing the deviation L of the optical axis was 10 to 80 degrees. This deviation of the optical axis differs depending on the constituent pixel pitch described later.

Production Example of Light Modulation Element (Phase Modulation Optical Element) Next, the light modulation element (liquid crystal cell) described above based on the present invention.
FIG. 1 shows a method for manufacturing No. 3, especially a method for forming the alignment films 22 and 23.
~ FIG. 17 will be described.

As described with reference to FIGS. 30 to 32, in order to prevent the deterioration of the resolution at the time of pixel (pixel shifting) and improve the resolution, the two switch states (state 1 and state 2) of the element 3 are used. The bisector 16 of the angle formed by the liquid crystal director 8 is the plane of polarization of the light from the display element (Y direction, that is, wobbling direction).
Alternatively, it is necessary that the angle δ formed with respect to a line (X direction) orthogonal to the polarization plane is ideally 22.5 degrees. If the alignment process is performed in the direction of this angle δ, the liquid crystal directors are positioned at substantially equal angles on both sides of this alignment process direction at the time of switching.
The switching described in 32 can be performed. Moreover, it has already been described that the dependence on the element environmental temperature can be reduced by setting the angle δ.

Therefore, such an angle δ is substantially δ = 2
2.5 degrees (The allowable range is 22.5 degrees ± 5 degrees, that is, 17.5 degrees
The present inventor has found that the alignment treatment may be performed in the direction corresponding to δ above when forming the alignment films 22 and 23.

SiO oblique deposition film: FIGS. 1 to 4 schematically show a deposition apparatus for forming such an alignment film by SiO oblique deposition.

First, as shown in FIG. 37, a transparent ITO film having a thickness of 40 nm (surface resistance 100 Ω / cm ² ) is formed by, for example, a sputtering method.
A glass substrate 20 or 21 on which 13 or 14 is formed is produced. In the following description, one substrate, for example 20, will be mainly described, but the other substrate 21 can be processed in the same manner.

Then, in the vacuum chamber 80, a tantalum boat (manufactured by Nippon Bucks Metal Co., Ltd.) 82 containing SiO powder (purity 99.99%: manufactured by Furuuchi Chemical Co., Ltd.) 81 was heated by a power source 120 (resistance By heating), the glass substrate 20 with the ITO film on the boat 82 was vacuum-deposited.

In this vapor deposition, the angle α formed by the normal line 83 of the substrate 20 and the vertical line 84 of the vapor deposition source is 85 degrees (see FIG. 2B), the substrate temperature is 170 ° C., and the vacuum degree is 8 × 10 ^-6. Torr, deposition rate
The condition was 0.1 nm / sec and the substrate azimuth angle δ was 22.5 degrees. After forming this SiO oriented film by oblique vapor deposition to a thickness of 50 nm, it was annealed in air at 300 ° C. for 120 minutes.

It should be noted here that FIG. 1 and FIG.
As clearly shown in (A), the substrate 20 is fixed on the holder 87 so that the direction 86 of the substrate 20 with respect to the vapor deposition direction 85 of SiO makes an angle δ in advance, that is, substantially 22.5 degrees. That is.

A plurality of substrates 20 are fixed to the inclined bottom side of the holder 87 as shown in FIG. Further, the holder 87 is attached to the guide rail 88 along the inner wall of the vacuum chamber 80 by the connecting rod 89 so that the holder 87 can be rotated at any position along the guide rail 88.

As described above, the orientation of the obtained SiO alignment film 22 is obtained by arranging the substrate 20 with an angle δ (= 22.5 degrees) with respect to the vapor deposition direction and performing oblique vapor deposition of SiO. The direction 90 is shifted counterclockwise by an angle δ with respect to the vapor deposition direction (that is, the Y direction in FIG. 30) as shown in FIG. This alignment direction 90 is the same as that of the liquid crystal director 2 described above.
It corresponds to the bisector 16 of the angle formed by the two switch states.

Similarly, for the other substrate 21,
As shown in FIG. 6, the SiO alignment film 23 thus obtained is fixed by the holder 87 so as to have a mirror image positional relationship with the case of the substrate 20 and SiO oblique vapor deposition is performed. The orientation direction 90 'is offset from the Y direction in the clockwise direction by an angle δ.

As shown in FIGS. 8 and 9, the alignment treatment directions 90 and 90 'of the alignment films 22 and 23 obtained above are mirror images (FIG. 9) or wobbling with respect to the axis (Y) of the wobbling direction. There is a mirror image relationship (FIG. 8) with respect to the axis (X) in the direction orthogonal to the direction.

Then, the heads a, a'and the tails of the respective alignment treatment directions 90, 90 'of the respective alignment films 22, 23 are set.
l) and substrate 20 as shown in FIG.
When 21 are opposed to each other, an antiparallel cell can be manufactured. On the contrary, when the heads a and a ′ are overlapped with each other as shown in FIG. 9, parallel-oriented cells can be manufactured.

10 to 11 show an example in which the alignment film is formed of the following various polyimide films in place of the above-mentioned SiO oblique vapor deposition.

JALS214, JALS246: As a liquid crystal alignment film, a polyimide film (JALS2) having a thickness of 20 to 100 nm is used.
14, JALS246: manufactured by Japan Synthetic Rubber Co., Ltd., concentration
1.5 wt%) was applied with a spinner (manufactured by Kyoei Semiconductor Co., Ltd.). The spin coat at this time was 100
It was performed under conditions of 0 rpm for 10 seconds and then 3000 rpm for 30 seconds, and then an annealing treatment was performed in air at 180 ° C. for 20 minutes to remove the solvent.

SAN EVER 305: 20 as a liquid crystal alignment film
A polyamic acid (San Ever 305: manufactured by Nissan Kagaku Co., Ltd., concentration: 4.3 wt%) was applied to a thickness of up to 100 nm by a spinner (manufactured by Kyoei Semiconductor Co., Ltd.). Spin coating at this time was first performed at 1000 rpm for 4 seconds, then at 3500 rpm for 30 seconds, and then in air at 80 ° C for 15 minutes, then 170 seconds.
Heat treatment was performed at 60 ° C. for 60 minutes to form a polyimide.

Sun Ever 715: 20 as a liquid crystal alignment film
Polyamic acid (San Ever 715: Nissan Chemical Co., Ltd., concentration 4.3 wt%) was applied to a thickness of up to 100 nm with a spinner (Kyoei Semiconductor Co., Ltd.). At this time, spin coating was first performed at 1000 rpm for 4 seconds, then at 3500 rpm for 30 seconds, and then in air at 80 ° C. for 15 minutes, and further 240 seconds.
Heat treatment was performed at 60 ° C. for 60 minutes to form a polyimide.

AL1524: As a liquid crystal alignment film, 20 to 10
A 0 nm-thick polyamic acid (Optomer AL1524: manufactured by Nippon Synthetic Rubber Co., Ltd., concentration: 12 wt%) was applied by a spinner (manufactured by Kyoei Semiconductor Co., Ltd.). that time,
Spin coat at 1000 rpm for 4 seconds, then 3500 rpm for 3 seconds.
Perform for 0 seconds, then in air at 50 ° C for 20 minutes, then
Heat treatment was performed at 180 ° C. for 120 minutes to form a polyimide.

AL3046: As a liquid crystal alignment film, 20 to 10
A polyamic acid (Optomer AL3046: manufactured by Nippon Synthetic Rubber Co., Ltd., concentration: 14 wt%) was applied to a thickness of 0 nm with a spinner (manufactured by Kyoei Semiconductor Co., Ltd.). that time,
Spin coat at 1000 rpm for 4 seconds, then 3500 rpm for 3 seconds.
Perform for 0 seconds, then in air at 50 ° C for 20 minutes, then
Heat treatment was performed at 180 ° C. for 120 minutes to form a polyimide.

When the polyimide film is formed on the substrate as described above, the temperature in the clean room is 20 to 28 ° C. and the humidity is 45.
If the operation is performed at a rate of not more than%, a film will be uniformly formed on the substrate.

Thus, the substrate on which the polyimide film is formed is subjected to rubbing treatment for the purpose of aligning liquid crystal molecules in a certain direction. For this rubbing process, the rubbing apparatus shown in FIGS. 10 and 11 is used.

In this apparatus, a buff material (Bemberg CF: made by Asahi Kasei Co., Ltd., rayon: Yoshikawa Kasei Co., Ltd., etc.) 101 is wound around a roller 100 which can be vertically adjusted on a support base 107, and a substrate 20 A plurality of them were tilted substantially δ = 22.5 degrees with respect to the reference line 105, and fixed on the rotary table 102 for angle adjustment by a vacuum chuck. The rotary table 102 is provided on a stage 104 that can reciprocate on a guide rail (not shown) with respect to the roller 100 by using a pump 103 as a drive source.

The rubbing condition is that the pressing amount of the substrate with respect to the roller 100 (actually, the buff material 101) is 0.1 to 0.
2 mm, the stage 104 was moved at a speed of 150 mm / min, and the roller 100 was rotated at a speed of 95 rpm.

By such rubbing, the orientation film 22 on the substrate 20 is oriented in the direction indicated by 110 in FIG. 12 (that is, δ = 22.5 degrees with respect to the Y direction). On the other hand, when the same process is performed on the substrate 21 (however, as shown in FIG. 13, the reference line 105
On the other hand, it is tilted by an angle δ on the side opposite to the above. ) The alignment treatment direction 110 'forms δ = 22.5 degrees with respect to the Y direction, and is in a mirror image relationship with the alignment treatment direction 110 in the X direction.

Therefore, antiparallel or parallel cells can be manufactured by disposing these two substrates 20 and 21 facing each other in the same manner as shown in FIG. 8 or 9.

As mentioned above, the method according to the invention is
It is characterized in that the substrate is placed with an angle of δ = 22.5 degrees with respect to the reference line in advance, and SiO oblique deposition and rubbing of the polyimide film are carried out. It is possible to easily and reliably orient the liquid crystal molecules by inclining them by 22.5 degrees simply by disposing them and assembling the cell as described above.

On the contrary, by the conventional method, δ
= If you try to tilt it by 22.5 degrees, you will need to tilt the substrate 22.5 degrees with respect to the viewfinder cell when assembling the cell, as the substrate will be installed in the same direction as the conventional evaporation or rubbing direction. . In this case, the alignment direction may deviate from the predetermined direction, and
The work is also troublesome.

The above-described alignment treatment by the method according to the present invention is a suitable method for shifting the picture elements in the vertical (Y) direction or the horizontal (X) direction of the screen, but various other alignment treatments are possible. There is a direction.

For example, in the case of the vertical direction and the horizontal direction, FIG.
As shown in (1), ideally, the alignment process should be performed with an inclination of 22.5 degrees with respect to the pixel shift direction or the direction orthogonal thereto (a, b, c or d), (a ', b', c'or d ')
is necessary. The allowable range is preferably 22.5 ± 5 degrees. In addition, the parallel alignment (a,
a'overlap), anti-parallel orientation (a, a'with Head
There are two types).

Furthermore, as shown in FIG. 15, when the picture elements are displaced in the oblique direction, it is necessary to arrange the picture element displacement directions so as to rotate on the substrate surface. In this case, the diagonal direction is defined by the pixel arrangement, the pixel density or the aspect ratio of the screen.

As described above, these alignment treatment directions are defined by the oblique deposition direction of the inorganic material such as SiO or the rubbing direction of the organic alignment film such as polyimide or polyamide.

Structural Example of Light Modulation Element (Phase Modulation Optical Element) As will be described later (explained in FIG. 46, FIG. 51 and FIG. 52), it is effective to divide the transparent electrode of the screen into five in the vertical direction. However, here, a cell having such a five-divided electrode will be described in connection with the above-mentioned alignment treatment.

That is, as shown in FIG. 16, one electrode 13 of the cell
Was divided into 5 parts in the vertical direction of the screen. Here, in order to increase the resolution in the vertical direction, it is necessary to switch the alignment of FLC molecules between the direction perpendicular to the long axis direction of the electrode and 45 degrees from this direction, and the following alignment was performed.

That is, with respect to the five-divided electrode 13, the azimuth angle during vapor deposition was adjusted in a direction tilted to the left by 22.5 degrees with respect to the pixel shift direction, and the oblique vapor deposition of SiO was performed. In addition, the vapor deposition conditions and the heat treatment after vapor deposition are as described above.
Further, the counter electrode 14 is not divided as shown in the figure, and it is necessary to rotate the counter electrode in the direction opposite to the direction of the five-division electrode side. That is, the orientation processing directions 90 and 90 'of the cell in which these are combined need to have a mirror image relationship with respect to the axis of the pixel shift direction or the axis orthogonal thereto.

Then, orientation processing is performed in such a direction,
The cell was assembled so that these orientation directions were parallel or antiparallel. As shown in FIG. 37, the cells were manufactured by using a flat sphere (Catalyst Kasei Co., Ltd.) with a diameter of 2.2 μm.
UV-curable adhesive (Photorec: Sekisui Fine Chemical Co., Ltd.) containing 0.3% by weight of 25% by weight is screen-printed to form a seal pattern around the glass substrate. The cell gap was taken and the adhesive was cured by UV irradiation.

Ferroelectric liquid crystal was injected into the cell thus manufactured through the cuts (that is, liquid crystal injection holes) in the above-mentioned seal pattern under reduced pressure at an isotropic phase temperature, and after gradually cooling, the liquid crystal attached around the injection holes was removed. After the removal, a FLC cell was completed by sealing with an ultraviolet curable adhesive (UV1000 manufactured by Sony Chemical Co., Ltd.).

Between the opposite electrodes of this FLC cell, ± 30 V, 30
The liquid crystal orientation was promoted by applying a square wave voltage of Hz for 10 seconds. Further, in this cell, the orientation of the liquid crystal director in each state when an electric field is applied, or the orientation of the liquid crystal director in a memory that is stored when the electric field is removed after the electric field is applied is determined by a polarization microscope and a birefringence measuring device AD.
It was determined using R-60XY (Oak Seisakusho Co., Ltd.). In a polarization microscope, a polarizer and an analyzer are arranged orthogonally, a cell is placed between them, and the stage is rotated, so that the orientation can be determined from the extinction position (darkening angle). However, since it is not possible to distinguish whether the direction is parallel or orthogonal to the liquid crystal director, it can be strictly determined by measuring the slow axis of the birefringence measuring device.

As a result, as shown in FIG. 17, it was confirmed that the liquid crystal director 8 is tilted at both sides of the alignment treatment direction at substantially the same angle. This angle was 0 ± 2 ° and 45 ° ± 2 °. As a result, as described above, the polarization plane could be reliably rotated by 90 degrees.

In addition to the orientation processing directions described above, FIG.
By setting the vapor deposition azimuth angle of the divided electrode 13 to the right at 22.5 degrees and setting the orientation processing direction of the counter electrode as a mirror image thereof, the direction of the liquid crystal director when applying an electric field or during memory also has a mirror image relationship, The pixel shifting effect was equivalent to the above case. Furthermore, even by the processing in the direction orthogonal to the orientation processing direction, as described in FIG. 14, the direction of the liquid crystal director is obtained by rotating them by 90 degrees, and the pixel shifting effect is the same in these cells. there were. Also, the same effect could be obtained by using an organic rubbing film as the alignment film.

The above-mentioned cell is useful as a light modulation element for wobbling (picture element shifting), and high resolution of a display or the like can be achieved. Further, when the above-mentioned split electrode structure is not used, it can be applied to increase the resolution of the image pickup device. Hereinafter, this wobbling will be described in more detail.

Driving Method and Operation for Higher Resolution of Liquid Crystal Display Element In the 2: 1 line interlaced scanning method of NTSC, one field (one frame) can be completed in two fields. Then, in the first (odd) field and the second (even) field,
They interpolate with each other with respect to vertical position information,
This is a method of maintaining the resolution by increasing the number of fields per second. However, since the odd field and the even field are overwritten on the same scanning line especially when the number of vertical pixels is small as in a liquid crystal display element, the original resolution is lowered.

Here, the pixel shift is performed in synchronization with the odd field and the even field, and the afterimage effect by the high-speed image replacement is applied to increase the vertical resolution. The shift amount of the pixel shift will be described below. Actually, the liquid crystal has dot-sequential or line-sequential scanning and is scanned in time series, but in the description here, they are handled at the same time so that the principle can be easily understood.

In the case of a monochromatic display element, a three-plate type color display element or a color sequential display element:
Since one switching element corresponds to one picture element, simply shift the picture element on the optical axis by half the distance between the centers of gravity in the picture element shifting direction of one picture element (center-to-center distance between constituent display pixels). Due to the shift in the direction, the resolution is increased, and at the same time, the non-display area (for example, the black matrix) between the pixels becomes inconspicuous. However, the shift need not be exactly half the distance between the centers of gravity of the picture elements.

That is, as shown in FIG. 40, the effective shift amount differs depending on the difference in the aperture size between the black matrix portion and the constituent pixel portion. When the black matrix portion is equal to or larger than the aperture of the constituent pixels, the shift (a) of half the constituent pixel pitch in the direction in which high resolution is desired is optimal, but the tolerance is recognized as the shift of the pixel position. Half of the constituent pixel aperture is required. Further, when the black matrix portion is smaller than the aperture size of the constituent pixels, at least the shift of the length of the black matrix portion is effective (b, c).

With respect to the length component in the pixel shift direction, the length of the black matrix portion is L _B and the aperture of the constituent pixel is L _A.
Then, the pixel pitch becomes L _P = L _A + L _B , and the pixel shift amount L is Min (L _B , L _A / 2) ≦ L ≦ Max (L _P −L _B , L
Represented by _P -L _A / 2).

If this equation is expressed by using L _P and L _A , Min (L _P −L _A , L _A / 2) ≦ L ≦ Max (L _A , L
The _P -L _A / 2). Note that Min (x, y), Max in each of the above equations
(x, y) is a function that gives a small value or a large value of x and y, respectively.

If pixel shifting is performed in the vertical direction as in this example, the resolution in the vertical direction is increased as shown in FIG. Similarly, if the pixel shift is performed in the horizontal direction, the resolution in the horizontal direction is increased (FIG. 42). Further, if the pixel shift is performed in the diagonal direction, the resolution is increased in the vertical and horizontal directions (FIG. 43).

In the case of a color liquid crystal display element having a color filter: In a normal color display element, one pixel is composed of trio of R, G and B color filters. R,
The G and B arrangement methods include in-line arrangement (Fig. 44) and delta arrangement (Fig. 45), but the optical axis shift here is the closest RGB trio area in the pixel shift direction, which is one of the distances between the centers of gravity. /
The length should be 2.

The pixel shift direction of such a pixel shift element can improve the resolution in the shifted direction by the two-dimensional pixel shift including not only the vertical direction but also the horizontal direction or the diagonal direction. Furthermore, the pixel shift range is
By setting the constituent pixel aperture L _A for the length component in the pixel shift direction to that of an RGB pixel trio and setting the length of the black matrix portion to L _B , the same conditions as those of the above-mentioned monochromatic display element are obtained. You can

Range of the number of divisions of the drive electrodes in the picture element shifting operation:
In principle, a pixel shift synchronized with each switching per pixel is required. In this case, in the case of dot-sequential scanning, picture element shifting elements corresponding to the number of pixels like a TFT (Thin Film Transistor) matrix are required. Further, in the case of line-sequential scanning, it is necessary to divide the electrodes by the number of horizontal scanning lines.

Therefore, when the number of horizontal scanning lines of the display element whose resolution is to be increased is N, it is ideal to divide the transparent electrode into 1 / N in the vertical direction during line-sequential scanning. But,
In order to increase the resolution, it is necessary to use picture element shifting elements that are equivalent in cost. Therefore, the present inventor considered that the upper limit of electrode division can be lowered by a human factor to reduce the cost, and conducted the following experiment.

In combination with the above TFT color liquid crystal display element, the timing of switching the ferroelectric liquid crystal element in synchronization with the vertical synchronizing signal was taken. The FLC element on the entire panel was switched without considering the time series data. Even if it went, about 1/4 of the vertical direction of the panel was improved in resolution from 240 TV lines to 370 TV lines.

From the experiments here, it was found that the resolution enhancement is effective even in the vertical division up to about 1/4.
That is, in order to increase the resolution, the pixel shift element to be combined with the display element having the horizontal scanning line number N is divided into N in the vertical direction.
One division is sufficient, but N divisions to 3 divisions are preferable in order to increase the resolution of the entire panel. Furthermore, considering the electrode processing accuracy and cost, N / 2 or (N + 1)
It is preferably less than or equal to any integer division of / 2.

Specific example of high resolution of FLC picture element shifting element with 5-divided electrode configuration: FIG. 46 shows an example of combination of divided electrodes. This divided electrode is a transparent electrode (I
(TO) 13 and 14 were formed, and the electrode was etched so as to be divided into five parts. Distance between ITO electrodes (etching part) 10μ
m. It is necessary that the distance between the electrodes be larger than the cell gap (and shorter than the non-display portion) in order to prevent dielectric breakdown due to the potential difference between the electrodes, that is, withstand voltage.
Here, the cell gap is set to 1 μm to 3.0 μm. It is easily understood that the combination of the divided electrodes may be such that one side is the common electrode and both sides are the divided electrodes.

Further, a SiO alignment film is used as the alignment film, and the cell assembling method and the liquid crystal injecting method are the same as those of the monopolar cell. The liquid crystal alignment direction was set in consideration of the pixel shift direction.

Regarding the sync signal of the picture element shifting element: Interlace scanning moving image, for example, 24 frames per second for movies, 25 frames per second for television
I'm sending one or thirty images. However, at 24 to 30 sheets per second, the flicker interference is great, and it can not be used at all.
For this reason, one frame is radiated twice each in a movie and 48 frames are repeated every second, and in television, the number of repetitions per second is increased by using the interlaced scanning method without increasing the transmission bandwidth. The Japanese domestic standard uses the 2: 1 line interlaced scanning method.

That is, as shown in FIG. 47, the scanning started from the point a reaches the point b in the horizontal scanning of N / 2 times, moves to the point c in the vertical retrace line period, and further the horizontal scanning is performed N / 2 times. The scanning reaches point d, and returns to point a again during the vertical baseline period. The period from d to b is called the first (odd) field, and the period from b to d is called the second (even) field. In the 2: 1 line interlace scanning system, one field (one frame) can be completed in two fields. In addition, there are 3: 1 and 5: 1 line interlace scanning systems.

When the screen display of the line-sequential scanning such as the NTSC system is performed, there is little problem in the resolution because the current CRT is analog, but liquid crystal, plasma, EL
For a display with discrete pixels, such as, for example, a considerable amount of horizontal position information is lost due to the discrete pixel array, scanning line information is lost, or the position resolution of the luminance signal is reduced ( That is, the resolution of the display is lowered) as described above.

Here, a concrete method for setting the timing of the picture element shifting (wobbling) will be described. TV signal, Figure 48
As shown in, each field is composed of a luminance signal, a vertical synchronizing pulse, a horizontal synchronizing pulse, a color signal, and a color synchronizing pulse. Here, the vertical sync pulse of the odd field (first field) and the even field (second field) is detected, a sync signal is sent from this to the FLC driver, and then a delay is given to each channel in the driver. The drive waveform may be sent to the FLC cell.

Regarding the synchronization of the divided FLC element, the FLC drive circuit, and the video signal processing system: FIG. 49 shows the configuration of the electrodes, the connection of the drive circuit and the video signal processing system, and the synchronization method. That is, by the video signal processing device 40,
The respective sync pulses of the odd field (first field) and the even field (second field) and the RGB signal are supplied to the display element 2, and at the same time, the vertical sync pulse of each field is detected and the sync signal is sent to the FLC driver 41. Then, the drive waveform delayed in each channel in the driver 41 is sent to the FLC cell 3.

As shown in FIG. 50, the entire ITO side was used as a common electrode and the five-divided electrode side was divided into Ch1 to Ch5 and pulse-driven as shown. That is, the time of one field is divided into five with the detected vertical synchronizing signal as a reference, and each channel is sequentially delayed. Therefore, T
It is important that the driving of the N liquid crystal display element 2 and the driving of the FLC element 3 are synchronized. In addition, these drive waveforms are
A general FLC driving method and rectangular wave driving can be applied.

Further, a concrete method of changing the direction of shifting the picture elements will be described. A case of increasing the resolution in the vertical direction of the display element 2 (FIG. 51) and a method of increasing the resolution in the vertical and horizontal directions (FIG. 52) are shown. As a result, it was confirmed that the resolution was increased in each intended direction.

In the above 5-division FLC element, a high resolution was examined in consideration of drive conditions, optical arrangement, and pixel shift amount. As a result, a panel in a 0.7 inch, 103,000 pixel active matrix TN liquid crystal display was obtained. The resolution has been increased from 240 TV lines to 370 TV lines or more over the entire surface, and the black matrix, which is a non-display area, has become inconspicuous, and a high-resolution and smooth screen has been achieved.

These high resolution techniques can be used in any form such as direct view type, reflection type and projection type. this house,
53 to 54 show two examples of projection displays.

In the example of FIG. 53, the light from the halogen lamp 17 is guided to the display element 2 as a backlight through the cold filter 43, and after the above-mentioned wobbling process, the lens system is
An image is projected from 44 to screen 45.

FIG. 54 shows a mirror type display, which is a light source.
The light from 17 is passed through the filter 46, separated into predetermined wavelength lights (R, G, B) by the respective dichroic mirrors 47, made incident on the respective wobbling elements from the condenser lens 48, wobbled there, and then again. The combined image is projected on the screen 45.

The above-mentioned high resolution technique is used in the visible light wavelength range for application as a display.

Application to Image Pickup Element The present invention is not limited to the display element 2 described above, but the wobbling element 7 described above is arranged in the optical path connecting the image pickup element such as CCD composed of discrete pixels and the object. It also applies when.

The image pickup device 71 shown in FIGS. 55 and 56 according to the present invention.
Also in the case of applying to, the various conditions, principles, and explanations described in the above-mentioned display device are preferably adopted in the same manner. In the following, the contents similar to those of the above-described display device will not be particularly described repeatedly, but in comparison therewith, the description will be mainly given to those specific to the imaging device.

When an image pickup device, for example, a CCD is used, β = 45 in order to increase the resolution of the 1/3 inch CCD in the horizontal direction, the vertical direction, or the horizontal and vertical directions simultaneously.
The amount of pixel shifting was adjusted by adjusting the thickness d of the crystal plate as a degree. Since the horizontal pitch of the 1/3 inch CCD is 6.35 μm and the vertical pitch is 7.4 μm, the pixel shift amount for high resolution in each direction is
It may be set to 3.18 μm or 3.7 μm, which is about ½ of each pitch. Further, in the case of the pixel shifting in the diagonal direction, it is necessary to shift the length of the diagonal line of the rectangle having the horizontal and vertical components as the respective sides. At this time, the length may be 4.88 μm.

For example, to give a deviation of L = 3.7 μm, β = 45 degrees and d = 0.63 mm. Here, the range of β effective for expressing the deviation L of the optical axis was 10 to 80 degrees.

When the image pickup device is used, the subject, the polarizer, the FLC device, the birefringent substrate and the image pickup device are arranged in this order in the optical path connecting the subject and the image pickup device 4. In this case, the lens system, the iris, and the wavelength limiting filter may be arranged anywhere in the optical path connecting the subject and the image sensor.

As shown in FIGS. 55 and 56, when the switch state of the ferroelectric liquid crystal element 3 is the state 1, the irradiation light component a from the object 50 side passes through the lens 51 and the diaphragm 52, It is polarized by the polarizing plate 19 in the pixel shifting direction. Since the plane of polarization of light and the extraordinary optical axis 8 of the ferroelectric liquid crystal element 3 are parallel, the transmitted light is applied to the quartz plate 4 having birefringence while maintaining the plane of polarization. In the crystal plate 4, since the extraordinary optical axis of the crystal is included in the plane of incident polarization, the light polarized in the Y-axis direction is refracted in the direction in which the extraordinary optical axis of the crystal plate is inclined, and when it goes out to the air layer again. It becomes parallel to the optical axis, and there is a deviation from the optical axis of the incident light.
Each picture element of the D image sensor 53 is irradiated.

On the other hand, when the switch state of the ferroelectric liquid crystal element 3 is the state 2, since the polarization plane and the extraordinary optical axis 8 form an angle of about 45 degrees, the transmitted light rotates in the direction of the extraordinary optical axis. , Linearly polarized light (Y-axis direction) → elliptically polarized light → circularly polarized light → elliptically polarized light → linearly polarized light (X-axis direction), the polarization plane changes 90 degrees from the initial state, and the crystal plate 4 changes. Is irradiated.
Since the crystal plate 4 does not include the extraordinary optical axis of the crystal in the plane of incident polarization, the optical axis is maintained as it is without refraction, and it exits to the air layer again and is irradiated to each pixel of the CCD image pickup element 53. .
That is, the a'portion of the subject is imaged. The shift of the optical axis between the state 1 and the state 2 can be used as the operation principle of the pixel shifting.

Due to the ambient temperature of the element, the apparent cone angle deviates from 45 degrees (for example, 45 + γ degrees: where γ is 45> γ).
> -45), in the wobbling operation, when the optical axis of one of the liquid crystal directors in the switch state is ideally aligned parallel to or orthogonal to the polarization plane of the polarizing plate, the polarization plane of the transmitted light does not change in this switch state. . In this case,
Since the plane of polarization is not rotated, 100% of the light is refracted in the direction of the extraordinary optical axis of the crystal plate 4 as shown in FIG. At this time, there are almost no components other than the point a.

In the other switch state, since 45 + γ degrees, the polarization plane of the transmitted light rotates 90 degrees or more when γ is positive, and the polarization plane rotates up to 90 degrees when γ is negative. do not do. When the plane of polarization is completely rotated by 90 degrees, the component a'is almost 100% as shown in FIG. However, as shown in FIG. 57, when the rotation of the polarization plane is deviated from the angle of 90 degrees by γ, the component in the Y-axis direction also increases as the polarization component, and thus some leakage in the adjacent imaging pixels in the Y direction occurs. Occurs. Therefore, in this case, the effect of shifting the pixels, which should have a high resolution, is slightly reduced.

Therefore, for the same reason as described above with reference to FIG. 30, the bisector of the angle formed by the above two switch states is formed with respect to the polarization plane of the polarizing plate or the line orthogonal to the polarization plane. Ideally, δ forms an angle of 22.5 degrees. By arranging the liquid crystal directors 8 in this way, crosstalk occurs in both switch states, as shown in FIGS. 58 and 59, but the crosstalk in each switch state is small. Moreover, it was found that the sum is less than the crosstalk on only one side, so the effect of higher resolution is not diminished.

Here, the range of θ and the angle δ formed by the bisector of the two-switch state with the plane of polarization of light or the line orthogonal to it are clarified from the following wobbling experimental results.

That is, in the study of fixing the shaft on one side, θ = 26 to
It was confirmed that the resolution of CCD was increased in the range of 64 degrees due to the wobbling effect. Furthermore, high resolution with less coloring was achieved in the range of θ = 36 to 54 degrees.

Further, as a result of examining the position of the δ axis in the range of θ = 36 to 54 degrees, it was found that there was almost no coloring at δ = 22.5 ± 10 degrees, and high resolution could be achieved. Furthermore, θ = 36
In the range of ˜54 degrees and δ = 22.5 ± 5 degrees, crosstalk between fields is reduced, and the contrast ratio between fields is increased, resulting in higher resolution.

Note that the resolution evaluation here is performed by capturing an image of a grid fringe resolution evaluation panel and converting it into a video signal, and then CR.
It was determined by displaying on a T monitor and observing.

FIG. 60 shows a specific arrangement example. In the case of an optical system such as a video camera or a still video camera, since incident light from the outside world is not substantially polarized, a polarizing plate is inserted between the outside world (subject) and the ferroelectric switching element. The positional relationship with respect to the diaphragm does not matter. Other optical arrangements are subject-lens-aperture-
The order is polarizing plate-ferroelectric switching element-transparent substrate having uniaxial optical anisotropy-imaging element. The image pickup element to be combined here includes a CCD, a MOS type element, and the like.
It doesn't matter what kind.

Since such an image pickup element is a light receiving element, unlike a display element, it is possible to improve the spatial resolution (spatial separation ability) of a subject. Here, since it can be performed by the simultaneous method instead of the sequential method like the display element,
The switching part of the FLC element 3 may act on the entire surface of the CCD element at the same time and does not require spatial electrode division of the phase modulation element 3. That is, for example, the pixels of the CCD image sensor also
If there is no deviation of the optical axis because it is discrete, a for each pixel,
Although there are only b and c position resolutions, the frame is divided, and the information of a, b, and c are first accumulated in the simultaneous method and then transferred.
In the next field, the position information of a ', b', and c'is accumulated by the pixel shift of the ferroelectric liquid crystal element 3 by the simultaneous method,
By transferring and recombining with the first field, the vertical resolution is doubled.

In order to improve not only the vertical resolution but also the horizontal resolution, one frame must be further divided into three fields and four fields. For this reason, the high-speed response of the ferroelectric liquid crystal element is required. is there. Twisted nematic picture element shifting element, transmittance change 0 ~ 90
The minimum rise / fall time is about 15 msec (room temperature) in%, which is quite difficult to achieve even with the NTSC 2: 1 line interlace scanning method (1/60 seconds per field ((16.7 ms)). Furthermore, if the 4: 1 line interlace scanning method is applied with the same number of frames, it is 1/120 seconds (8.3 ms) per field, and it is impossible to follow up at all. It can be seen that the shift method is effective because its switching time is shorter than that of the TN liquid crystal. By the way, the rise and fall times of the ferroelectric liquid crystal element are in the order of μsec, and even the slowest one is several
It is less than ms.

In the case of a monochromatic image pickup device and a three-plate color image pickup device: one switching element unit corresponds to one picture element, so that the length of the half of the distance between the centers of gravity of one picture element in the resolution improving direction is simply The resolution is increased by shifting the optical axis in the direction of improving the resolution. Further, the permissible range is preferably 50% to 150% of the shift length.

In the case of an image sensor having a color filter:
One trio of R, G, B color filters constitutes one picture element. There are delta arrangement, in-line arrangement, etc. as the arrangement method of R, G and B, but the shift amount of the optical axis here is 1 / the distance between the closest R, G and B trio areas in the direction of resolution improvement.
The length should be 2. Further, the permissible range is 50 to 150% of the shift length.

A specific mounting example of the liquid crystal device on a video camera: Handycam TR-1 (manufactured by Sony Corporation) will be described. First, an infrared cut filter and a low pass filter which can be used therein will be described.

[1] Normal Imaging of Visible Light A semiconductor imaging device such as a CCD imaging device has a sensitivity range of
It extends to 380-1200nm. When a normal visible light image is captured, the near-infrared light region, which cannot be sensed by the human eye, is captured, which adversely affects the image. Therefore, it is necessary to insert the infrared cut filter 61 between the subject 50 and the CCD 53 as shown in FIG.

Here, an example in which an infrared cut filter (cuts a wavelength of 700 nm or more) 61 is combined with the pixel shift element is shown. Further, since the quartz plate used for the wobbling element is insufficient in cutting high frequency components, an optical low pass filter is required. Therefore, a crystal low-pass filter (a plurality of crystal plates) for 7-point blur that is generally used in a high-quality CCD video camera
It consists of 64. ) Was incorporated (Fig. 61, Fig. 62).

In this low-pass filter, incident light is made into two-point blur by utilizing its birefringence in one crystal plate, and a two-point image is formed by laminating another crystal plate rotated around the optical axis. It is possible to improve the low-pass filter characteristics by blurring the four-point image into a seven-point image on the third crystal plate.

That is, by blurring the incident light in this way, it is possible to remove the components of the image information having a high spatial frequency, and avoid problems such as moire fringes and color false signals. However, in the case of one crystal plate, the high frequency component can be cut or dispersed only in the y direction, but in the above, the high frequency component can be cut or dispersed in both the x and y directions, and the high frequency component of the high frequency component can be retained while maintaining the sensitivity of the low frequency component. It is possible to further eliminate the influence on the image (the generation of a moire fringe pattern or a color false signal in the image output of the formed image).

FIG. 63 shows an implementation example not using such a low-pass filter, and FIG. 64 shows an implementation example using the same low-pass filter.
It was shown to. In each case, the picture element shifting element (wobbling element) 7 is provided in front of the CCD 53.

When the low-pass filter 64 is used, the first extraordinary optical axis of the low-pass filter is the polarization at the time of wobbling.
When the angle is 30 to 60 °, the effect of the low pass filter is obtained, but in other cases, the low pass filter characteristic changes in the field. At this time, by inserting a λ / 4 plate (not shown) between the picture element shifting element 7 and the optical low-pass filter, the difference in the low-pass filter characteristics between fields can be reduced and the low-pass filter characteristics can be sufficiently exhibited. Like

FIG. 65 shows a color separation camera system using three CCDs. However, CCD drive circuit,
The wobbling element drive circuit is omitted.

[2] In the case of imaging infrared light By utilizing the near-infrared light range of a semiconductor image sensor such as a CCD image sensor, it is possible to image only the near-infrared light range which cannot be sensed by the human eye. . In this case, it is not necessary to intentionally insert an infrared cut filter.

In this case, to image only infrared light, it is necessary to insert a visible light cut filter (cuts 760 nm or less) between the subject and the CCD. Accordingly, the temperature distribution of the subject can be imaged. Since the imaging wavelength at this time extends to 700 to 1200 nm, the phase difference of the pixel shift element needs to be 350 to 600 nm, which is half the wavelength.

Although the embodiments of the present invention have been described above, the above embodiments can be further modified based on the technical idea of the present invention.

For example, the structure, material and shape of each component, the assembling method, and the like, including the above-described liquid crystal element, may be variously changed. The substrate is not limited to the glass plate and may be any other optically transparent material. As the alignment film, an organic vapor deposition film may be used in addition to the above-mentioned ones, and various alignment treatment methods may be performed. Various liquid crystals can be adopted.

The object to which the present invention is applied can be used not only as a wobbling element that can be incorporated in an optical system such as the above-mentioned display device or image pickup device, but also as a light modulation element for other purposes.

[0196]

As described above, the present invention provides an optical modulator used for performing wobbling for shifting the optical axis of incident light in a predetermined direction by combining with an optically transparent birefringent medium. In the production, during the formation of one alignment film, the alignment treatment is performed in a direction forming an angle of substantially 22.5 degrees with respect to the wobbling direction or the direction orthogonal thereto, and the other alignment film facing the other alignment film. The method for producing a light modulation element is characterized in that the alignment treatment direction of the alignment film of (1) and the alignment treatment direction of the one alignment film have a mirror image relationship with respect to an axis in the wobbling direction or an axis orthogonal to the axis. The above alignment treatment direction can always be realized with good reproducibility, and the liquid crystal can be aligned easily and reliably in the same direction.

Therefore, at the time of switching during wobbling, the liquid crystal directors can be positioned at substantially equal angles on both sides of the alignment treatment direction, and the switching state necessary for wobbling can be reliably realized, resulting in high resolution. Can be achieved. Moreover, since the orientation processing direction can be set with certainty, it is possible to provide an element whose dependency on the element environmental temperature is reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a vacuum vapor deposition device during an alignment treatment according to an embodiment of the present invention.

FIG. 2 is a schematic front view and a side view showing an arrangement state of substrates at the time of vapor deposition.

FIG. 3 is a sectional view taken along line III-III in FIG. 1 of the vapor deposition device.

FIG. 4 is an enlarged cross-sectional view of the substrate of FIG. 2B and its holder.

5A and 5B are a schematic front view and a plan view showing an alignment treatment direction by the vapor deposition.

FIG. 6 is a schematic front view showing an arrangement state of substrates during alignment processing on another substrate.

7A and 7B are a schematic front view and a plan view showing the same alignment treatment direction.

FIG. 8 is an explanatory diagram of an antiparallel alignment cell.

FIG. 9 is an explanatory diagram of a parallel alignment cell.

FIG. 10 is a schematic perspective view of a rubbing device during alignment processing according to another embodiment of the present invention.

FIG. 11 is a plan view of a main part of the rubbing apparatus.

FIG. 12 is a schematic plan view showing an alignment treatment direction by the same rubbing.

FIG. 13 is a schematic plan view showing an alignment treatment direction of another substrate by rubbing.

FIG. 14 is a schematic view showing various alignment treatment directions.

FIG. 15 is a schematic view showing another orientation processing direction.

FIG. 16 is a schematic plan view showing an alignment treatment direction of a cell having five-divided electrodes.

FIG. 17 is a schematic plan view illustrating a liquid crystal alignment state in the same cell.

FIG. 18 is a schematic view of a display device in a state 1 to which the present invention is applicable.

FIG. 19 is a schematic view of the same display device in a second state.

FIG. 20 is an explanatory diagram of a cone angle of a ferroelectric liquid crystal (FLC) used in the display device.

FIG. 21 is a graph showing the temperature dependence of the cone angle.

FIG. 22 is a graph showing the temperature dependence of the same cone angle in another liquid crystal.

23 is a schematic view similar to FIG. 19 for explaining the deviation of the abnormal optical axis of FLC of the display device.

[Fig. 24] Fig. 24 is a diagram for describing crosstalk between fields during wobbling (picture element shifting).

FIG. 25 is a schematic diagram of a system for measuring the degree of polarization during wobbling.

FIG. 26 is a graph showing a change in transmission spectrum of liquid crystal.

27 is a graph similar to FIG. 26.

FIG. 28 is a graph showing changes in the transmittance.

FIG. 29 is a diagram for explaining a preferable cone angle of liquid crystal.

FIG. 30 is an explanatory diagram of an improved liquid crystal director direction.

FIG. 31 is a schematic view similar to FIG. 19 in the second state of the liquid crystal director.

FIG. 32 is a schematic view similar to FIG. 18 in the state 1 of the liquid crystal director.

FIG. 33 is a schematic diagram of a specific example of the display device in each switch state.

FIG. 34 is a schematic diagram of a case where a normally white TN liquid crystal display element is used in the display device.

FIG. 35 is a schematic diagram of a case where a normally black TN liquid crystal display element is used in the display device.

FIG. 36 is a schematic diagram of a display device using a display element having a small degree of polarization.

FIG. 37 is a cross-sectional view of a liquid crystal cell as a phase modulation element using a FLC liquid crystal element.

FIG. 38 is a waveform diagram showing various driving methods of the same phase modulation element.

FIG. 39 is an explanatory diagram of an optical axis shift due to a birefringent medium.

FIG. 40 is a schematic diagram showing the shift amount in each case during wobbling (pixel shifting).

FIG. 41 is an explanatory diagram of a wobbling state.

FIG. 42 is an explanatory diagram of another wobbling state.

FIG. 43 is an explanatory diagram of still another wobbling state.

FIG. 44 is an explanatory diagram of a wobbling state of an RGB inline array display element.

FIG. 45 is an explanatory diagram of a wobbling state of an RGB delta array display element.

FIG. 46 is a schematic perspective view showing divided electrodes in the phase modulation element.

FIG. 47 is an explanatory diagram of an interlaced scanning method.

[Fig. 48] Fig. 48 is a waveform diagram of a synchronization signal in each field of the television.

FIG. 49 is a block diagram showing a connection relationship between respective elements of the display device.

[FIG. 50] FIG. 50 is a drive waveform diagram of an electrode-splitting type phase modulation element.

FIG. 51 is a schematic view of a display device using the same element.

FIG. 52 is a schematic view of another display device using the same element.

53 is a cross-sectional view of a display to which the display device is applied.

FIG. 54 is a cross-sectional view of another application example of the display.

[Fig. 55] Fig. 55 is a schematic diagram of the imaging device in a state 1 to which the present invention can be applied.

[Fig. 56] Fig. 56 is a schematic diagram of the imaging device in state 2.

FIG. 57 is a schematic diagram similar to FIG. 56 for explaining the deviation of the abnormal optical axis of the FLC of the imaging device.

58 is a view of the improved liquid crystal director in state 2; FIG.
FIG. 58 is a schematic view similar to 57.

FIG. 59 is a schematic view similar to FIG. 55 in the state 1 of the liquid crystal director.

FIG. 60 is a schematic diagram of a specific example of the imaging apparatus.

FIG. 61 is a schematic diagram of a mounted state of a crystal optical low-pass filter.

[Fig. 62] Fig. 62 is a principle diagram illustrating blurring caused by three crystal filters of the same.

[Fig. 63] Fig. 63 is a cross-sectional view of a mounting example of the imaging device.

FIG. 64 is a cross-sectional view of another mounting example.

FIG. 65 is a cross-sectional view of still another mounting example.

[Explanation of Codes] 1 ... (Liquid crystal optical) display device 2 ... (Liquid crystal) display element 3 ... Ferroelectric liquid crystal element 4 ... Birefringent medium 5 ... Display pixel 7 ... Wobbling element (picture element shifting element) 8, 10 ... Extraordinary optical axis 9 ... Polarization direction 13, 14 ... Transparent electrode 15 ... Liquid crystal 17 ... Light source 18, 19 ... Polarizer 20 , 21 ... Transparent substrates 22, 23 ... Alignment film 50 ... Subject 53 ... CCD element 71 ... Imaging device 80 ... Vacuum tank 81 ... Deposition source 85 ... Deposition direction 86 ... Board direction 87 ... Holder 88 ... Guide rail 90, 90 ', 110, 110' ... Orientation direction 100 ... Roller 101 ... Buff material 102 ... Rotating table δ ... Inclination angle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Eriko Matsui, 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Hidehiko Takanashi, 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Hidefumi Asahi 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Yang Eiho 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (7)

[Claims] 1. A plurality of optically transparent substrates provided with an optically transparent electrode and an alignment film in this order are arranged to face each other at a predetermined gap on the side of the electrode and the alignment film, A liquid crystal is injected into the gap and is combined with an optically transparent birefringent medium to manufacture an optical modulation element used for wobbling to shift the optical axis of incident light in a predetermined direction. At that time, when forming one alignment film, an alignment treatment is performed in a direction forming an angle of substantially 22.5 degrees with respect to the wobbling direction or a direction orthogonal thereto, and the other alignment facing the one alignment film. A method for manufacturing a light modulation element, wherein a film alignment treatment direction is made to have a mirror image relationship with an alignment treatment direction of the one alignment film with respect to an axis in the wobbling direction or an axis orthogonal thereto. 2. The method according to claim 1, wherein an allowable range of an angle formed by the alignment treatment direction with respect to the wobbling direction or a direction orthogonal thereto is 22.5 ° ± 5 °. 3. The method according to claim 1, wherein the alignment treatment directions of the alignment films facing each other are antiparallel or parallel to each other. 4. The method according to claim 1, wherein the alignment film is formed of an inorganic vapor deposition film, an organic vapor deposition film, or an organic rubbing film. 5. At least one selected from a ferroelectric liquid crystal, an antiferroelectric liquid crystal, and a smectic liquid crystal exhibiting an electroclinic effect.
The method according to claim 1, wherein a phase modulation optical element for wobbling in which a liquid crystal of a seed is injected is manufactured. 6. A phase-modulating optics which is provided by dividing at least one of electrodes facing each other in the wobbling direction and is used in combination with a birefringent medium in an optical path between a display element and an observation position to be high-resolution. The method according to claim 1, wherein the device is manufactured. 7. A phase-modulating optical element used in combination with a polarizing plate and a birefringent medium in an optical path between a subject and an image sensor to be high-resolution is manufactured.
The method described in any one of 1.