JPH0736054A - Optical device - Google Patents

Abstract

PURPOSE:To make it possible to efficiently attain a higher resolution and to improve mosaic-like dot plotting screen, etc., to a seamless continuous screen by making possible easy wobbling (shifting of picture elements) easy dealing with a video rate at a high speed for a display consisting of discrete pixels and a solid-state image pickup element consisting of discrete photodetecting pixels, etc. CONSTITUTION:This optical device is constituted by laminating plural pieces of elements 7-1, 7-2 each consisting of a phase modulation optical element 3 which is arranged with plural pieces of optical transparent substrates provided with optically transparent electrodes and oriented films in this order so as to face each other apart prescribed spacings on the sides of the electrodes and the oriented films and is injected with at least one kind of the liquid crystals selected from ferroelectric liquid crystals, antiferroelectric liquid crystal and smectic liquid crystals exhibiting an electric grading effect into the spacings and an optically transparent double refractive medium 4.

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 an optical device suitable for a display in which pixels are discrete such as (electroluminescence) and a solid-state imaging device represented by a CCD (charge coupled device) in which imaging pixels are discrete.

[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 image pickup pixels forming the CCD are 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.

However, the wobbling elements that have been proposed so far have a slow response speed and cannot be driven at a video rate, which is not practical and the device configuration conditions are insufficient. In addition, the spatial resolution of conventional elements was limited.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wobbling (picture element shifting) for a display composed of discrete pixels, a solid-state image sensor composed of discrete light-receiving pixels, etc. at a high speed and at a high video rate. It is an object of the present invention to provide an optical device capable of efficiently achieving a high resolution, and improving a mosaic-like point-drawing screen or the like into a seamless continuous screen.

[0009]

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. Ferroelectric liquid crystal (FL) is placed facing each other with a predetermined gap.
C), antiferroelectric liquid crystal (AFLC), and smectic liquid crystal (SmA) exhibiting an electroclinic effect.
A phase-modulating optical element in which a kind of liquid crystal (may be a mixed liquid crystal) is injected into the gap; and an optically transparent birefringent medium; Optical device.

According to the optical device of the present invention, in one wobbling element, the phase of the light is changed by the phase modulation optical element to shift the plane of polarization, and further the incident light is selectively refracted by the birefringent medium. In addition, since it is possible to further perform such an operation in another wobbling element in which such operations are combined, it is possible to effectively perform not only one-dimensional wobbling but also two-dimensional wobbling with respect to discrete pixels, and further improve the resolution (vertical and horizontal). Higher resolution in both directions) is possible. In addition, the mosaic-like dot-drawing screen can be improved to a seamless continuous screen, and the image quality can be improved.

In any of the liquid crystals such as the ferroelectric liquid crystal used for the above phase modulation optical element, the direction of the liquid crystal director easily changes in response to the action of the electric field, and the response speed is very fast (for example, rising and Both fall time μ
Since it is on the order of sec to several msec, which is much faster than the fall time of twisted nematic liquid crystals), it is possible to sufficiently drive at the video rate.

In the present invention, the phase-modulating optical element and the birefringent medium are sequentially arranged in the optical path between the display element and the observation position, which are to be increased in resolution, or between the subject and the image pickup element. A combination of wobbling elements may be arranged so that the display element or the image pickup element is wobbled one-dimensionally or two-dimensionally.

Further, the birefringent medium is made of a transparent substrate such as a crystal that gives a deviation of the optical axis depending on the polarization direction of the incident light, and is arranged so as to have an equivalent uniaxial extraordinary optical axis component in the wobbling direction. May be done. In this case, it is preferable that the extraordinary optical axis forms an angle of 10 to 80 degrees with respect to the wobbling optical system.

Further, a liquid crystal display element such as a twisted nematic liquid crystal, a ferroelectric liquid crystal or an antiferroelectric liquid crystal, in which a display element or an image pickup element which is to have a high resolution is composed of discrete pixels, and a light emitting diode or the like emits light. Type display element or CCD
And so on.

When the light from the display element or subject to be high-resolution is not polarized, an element for giving polarization is arranged in the optical path between the combination of the wobbling elements and the display element or subject. Is good.

In the present invention, n (where n is an integer) wobbling elements are combined so that the deviation of the optical axis of the birefringent medium extends to 2 ⁿ points, so that high resolution can be achieved. In this case, the spatial resolution can be further improved by combining birefringent media having different thicknesses.

A phase modulation element (for example, a chiral smectic liquid crystal element) for rotating the polarization plane by 90 ° ± 45 ° is arranged in the optical path between the combination of the wobbling element and the observation position or the image pickup element. When the modulation element is configured to align the polarization plane during wobbling by switching in synchronization with the change in the polarization direction during wobbling, when arranging a polarizing screen or the like on the light emission side of the wobbling element combination, It is advantageous when the reflectance has a polarization degree dependency.

When driving each phase modulation optical element in the combination of wobbling elements, if the driving cycle is at least four times the wobbling cycle, the driving cycle can be lengthened to support driving at the video rate. It will be easy.

In this case, when driving the respective phase modulation optical elements of the combined two wobbling elements, the driving cycle of each of these phase modulation optical elements is set to four times the wobbling cycle, and the phase of the driving cycle is set. When the liquid crystal elements are shifted 90 degrees from each other, the number of times of switching of the liquid crystal element can be reduced and the driving speed condition can be relaxed.

In the present invention, the above-mentioned "optical device" naturally means only a combination of the above wobbling elements, but also includes a display device, an image pickup device, etc. in which this combination is arranged. To do.

[0021]

EXAMPLES Examples of the present invention will be described below.

[1] One-dimensional two-point pixel shift First, the one-dimensional two-point pixel shift will be described with reference to FIG.

In the case of wobbling of the display element: the polarized light 6 from the liquid crystal display element (not shown) is the liquid crystal phase modulation element 3 (modulation element A, which is a chiral smectic liquid crystal optical element).
When the incident light is incident on the birefringent medium 4 and the plane of polarization is not changed (this is referred to as “switch state 1”), the plane of polarization is refracted because it is parallel to the extraordinary optical axis 10 of the birefringent medium 4. The optical axis shifts upward, and the emitted light 12 is directly perceived by the eye as a picture element at the position a, or directly after passing through a lens system or after being received by a reflection system such as a screen and then perceived by the eye.

Next, the plane of polarization is almost adjusted by the liquid crystal phase modulation element 3.
When rotated by 90 degrees (this is referred to as "switch state 2"), the polarization plane is perpendicular to the extraordinary optical axis of the birefringent medium 4, so that it is not refracted and the optical axis is not displaced. The picture element is perceived.

According to the wobbling element 7, an optical shift occurs between the above two states, and since this operation is performed within one frame, the resolution can be perceptually increased.

In the case of wobbling of the image pickup device: Since light from a subject (not shown) does not contain much polarization component, it is necessary to insert a polarizing plate between the subject and the phase modulation element 3. With this configuration, the light from the subject is polarized in one direction and then is incident on the liquid crystal phase modulation element 3 including the chiral smectic liquid crystal optical element, and when the polarization state is not changed, the polarization plane is not changed. Since it is parallel to the extraordinary optical axis of the refraction medium, it refracts and shifts the optical axis upward
It is incident on the image sensor.

Next, the plane of polarization is almost adjusted by the liquid crystal phase modulation element 3.
In the “switch state 2” rotated by 90 degrees, the plane of polarization is perpendicular to the extraordinary optical axis 10 of the birefringent medium 4 and thus is not refracted, and the optical axis is incident on the image sensor without displacement.

An optical shift occurs between these two states, and light from different places on the subject can be picked up by the same picked-up picture element. Therefore, images of two fields are sequentially transferred to the frame memory and one frame is transferred. By forming, the spatial resolution of imaging is improved in the pixel shift direction.

[2] Two-dimensional four-dot pixel shift As shown in FIG. 1, one-dimensional two-dot picture having phase modulation elements A and B composed of chiral smectic liquid crystal optical elements 3-1 and 3-2, respectively. Two sets of elements (7-1 and 7)
-2) Prepare (4-1 and 4-2 in the figure are birefringent media, 10
-1, 10-2 are the extraordinary optical axes), and the other element B is rotated 90 degrees around the incident optical axis with respect to one element A, combined and laminated, and two phase modulation elements are provided. Higher resolution in the vertical and horizontal directions is achieved by combining the switch states. Here, "switch state 1" means that the polarization plane of incident light is hardly changed, and "switch state 2" means that it rotates about 90 degrees.

FIG. 2 shows the relationship between the switch state and the pixel shift position, but it can be seen that the resolution is increased in the vertical and horizontal directions due to the shift of the pixel position.

In such wobbling, since the picture element shifting is performed four times within one frame or one field, all operations must be completed within 1/30 seconds or 1/60 seconds. So, for 1/120 second (about 8.3ms),
It is necessary that switching is completed within 20% of the time of 1/240 second (about 4.2 ms). That is, rising,
It is necessary that the fall response speed be approximately 0.8 to 1.6 ms or less, but in order to practically satisfy this condition between -10 ° C and 70 ° C, a chiral smectic liquid crystal device that exhibits high-speed response is required. It can be realized only by using.

However, in the switching pattern shown in FIG. 2, as shown in the waveform diagram of FIG. 3, the switching state of the modulation element A must be switched four times in one cycle.

Therefore, by changing the switching pattern as shown in FIGS. 4 and 5, the modulation element A can be driven by switching only twice in one cycle, and the picture elements in the vertical and horizontal directions are equivalent to the above. A shift can be achieved. That is, in driving an element composed of two sets of wobbling elements stacked, if a driving method in which the driving cycle of the two sets of elements is four times the pixel shifting cycle and the phases of the driving cycles are shifted from each other by 90 degrees, the liquid crystal is The drive speed specifications can be relaxed.
In this case, since the drive cycle can be lengthened, it becomes easier to support the video rate.

[3] When Projecting on Polarizing Screen etc. The polarization plane of the light during the wobbling operation is the same as the above [1],
As described in [2], the wobbling element 7-1 is simply used.
By simply combining and 7-2, the light whose polarization plane is switched by about 90 degrees will be mixed. When a polarizing screen 70 is used as shown in FIG. 7 for high brightness, sufficient high resolution characteristics cannot be obtained unless the polarization directions are aligned.

However, in the optical path connecting the wobbling element and the observer, the phase modulation element 73 (here, the chiral smectic liquid crystal element X) can further rotate the polarization plane by about 90 degrees.
By inserting, it is possible to align the polarization planes during wobbling.

FIG. 8 shows an example in which such a phase modulation element 73 is applied to two-dimensional four-point wobbling. As a result, as shown in FIG. 9, the polarization plane of the light emitted from the wobbling element can be aligned in one direction (that is, the vertical direction or the horizontal direction) by switching the phase modulation element 73. By aligning the polarization planes in this way, it is possible to improve the reflectance in the case where the reflectance has a polarization degree dependency as in a polarizing screen, and to realize high resolution by wobbling even when passing through the polarizing screen.

[4] One-dimensional pixel shift for 2 ⁿ field 1 frame In FIG. 10, a plurality of wobbling elements in which a liquid crystal phase modulation element and a birefringent medium are combined are provided 7-1, 7-2, ... −
1 shows a wobbling element formed by stacking n and n sheets.
In this case, in principle, the deviation of the optical axis given by the birefringent medium should be L, L / 2, L / 4, ... L / 2 ⁿ ,
Laminate wobbling elements. Specifically, the crystal plate 4-
The thickness of 1, 4-2 ... 4-n is d / 2 ^n, and d, d
/ 2, d / 4 ... d / ^2n, and so on. Further, by aligning the directions of the extraordinary optical axes of the birefringent medium at the time of stacking, driving each liquid crystal phase modulation element,
It is possible to perform picture element shifting having a spatial resolution of 2 ⁿ points between distances of length L (2-1 / 2 ⁿ ).

More specifically, when n = 3, as shown in FIG. 11, a one-dimensional pixel shifting element for eight fields and one frame can be realized. That is, if the deviation of the optical axis given by the crystal plate having the thickness d is L, the resolution can be increased by shifting the picture element by dividing the distance of 1.875 L into 8 points. Thus, the spatial resolution can be further improved by stacking birefringent media having different thicknesses.

[5] Two-dimensional picture element shift for 2 ⁿ × 2 ⁿ field 1 frame This picture element shift is described in the above [1] to [2].
The method of extension to [4] may be applied to the above [4]. As a result, it is possible to shift 2 ⁿ × 2 ⁿ points in two dimensions.

Specifically, by stacking four sets (where n = 2) of wobbling elements using quartz substrates having different thicknesses as shown in FIG. 12, 4 × 4 pixel shifts can be performed. High resolution can be achieved. Further, FIG. 13 shows that the resolution enhancement effect does not depend on the stacking order of the birefringent media having different amounts of deviation of transmitted light.

Next, the wobbling operation described above will be described in more detail. 14 and 15 are the same as those shown in FIG.
One wobbling element 7 will be described, but this will be understood as the operating principle of the elements of FIGS. 1, 7, 8 and 10 to 13 (the same applies hereinafter).

Here, a case where the wobbling element is applied to the liquid crystal optical display device 1 will be described. However, a liquid crystal display element (LC) sequentially arranged in the same optical path along the traveling direction of light.
D) 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 quartz plate. here,
For easy understanding, each component is a liquid crystal display device LCD.
Each of the sections corresponding to one of the constituent display pixels 5 is shown (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 (twist 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.

For the 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 the equivalent 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 for 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 may be a crystal plate. 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. 14, the ferroelectric liquid crystal element 3
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. 15, 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 an operation principle of the pixel shift. it can.

Here, FLC3 (the above-mentioned elements 3-1 to 3-1
The same applies to -n: The same applies to the following.) The cone angle of the liquid crystal that determines the switch state will be described. For ferroelectric liquid crystals (same for anti-ferroelectric liquid crystals), the switching behavior of liquid crystal directors by applying an electric field is that liquid crystal molecules follow Move on a virtual cone. Furthermore, the Smectic A liquid crystal (P145 of the same liquid crystal dictionary) that has an electroclinic effect is
Even when using the soft mode described in 9,
Each liquid crystal composition has a cone angle that is similar to the cone angle.

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 tin is doped into indium) 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.

Next, FIG. 17 shows a switch state of a concrete combination example of each element constituting the liquid crystal optical device. 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,
An example of combination with N liquid crystal is shown.

In the normally white TN liquid crystal display element shown in FIG. 18, 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 element shown in FIG. 19 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, it is clear that the present invention can be applied to any type of liquid crystal display element as long as the light emitted from the display element is substantially linearly polarized light.

Although the above-mentioned example relates to a display device having polarized light, the present invention can of course be applied to a non-polarized display device.

As shown in FIG. 20, 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 in order to make the light polarized. 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 that can be used here is 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
Although wobbling (picture element shifting) can be performed by arranging it in an optical path connecting a display such as an ED and an observer's retina, the phase modulation element 3 will be described in detail here.

As the usable element 3, the following [1]
Alternatively, [2] may be mentioned. [1] There are at least two states in the switch state of a ferroelectric liquid crystal, an antiferroelectric liquid crystal that can be driven at a video rate, or a smectic A liquid crystal having an electroclinic effect, and at least two of them are abnormal optical axes. Is 26-64
A chiral smectic liquid crystal element that forms an angle of degrees and is an element that is optically arranged so that the plane of polarization can be rotated.

[2] A transparent birefringent medium is a transparent substrate that shifts the optical axis depending on the polarization direction of incident light. Specifically, it is a component of an extraordinary optical axis that is equivalently uniaxial in the wobbling direction. Elements arranged so as to have.

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

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. After vacuum deposition of SiO at a substrate temperature of 170 ° C,
Firing was performed at 300 ° C. for 1 hour.

The substrate with the alignment film thus produced was assembled so that the alignment treatment directions were anti-parallel on the opposite surfaces, and the glass beads (true yarn ball: 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%. If the substrate area is large, 100 pieces of the true glomeruli at an average density on the substrate / 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) 15 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 in the present invention may be manufactured by Chisso Corp., Merck Co., Ltd., BDH, or a composition comprising, for example, the following ferroelectric liquid crystal compound or non-chiral liquid crystal, but the limitation is not limited thereto. In addition, the phase sequence is not limited, 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 which has a bookshelf structure in antiparallel and a chevron structure in parallel or a pseudo bookshelf structure in parallel depending on the combination of the alignment treatment directions. Clarified by analysis.

[0069]

[Chemical 1]

[0070]

[Chemical 2]

[0071]

[Chemical 3]

[0072]

[Chemical 4]

[0073]

[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.

<Anti-ferroelectric liquid crystal> The anti-ferroelectric 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 exhibiting 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 A tilt angle proportional to the applied electric field E occurs, such as Ε / k. Here, 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.

Fast response of FLC: rising (10-90
% T) and falling (90-10% T)
It shows fast response of sec order, guarantees sufficient response within one field, and achieves effective pixel shifting effect at video rate for the first time.

In particular, 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 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 shift 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 per field (16.7 ms)) is quite difficult to realize, and if the 4: 1 line interlaced 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.

On the other hand, 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 1 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.

Birefringent transparent substrate that shifts the optical axis depending on the polarization direction of incident light An equivalently uniaxial extraordinary optical axis 10 exists on the same plane as the Z axis as shown in FIG. 14, and Elements that are 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. 22, 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.

[0086]

[Equation 1]

Here, the range of β effective for expressing the deviation L of the optical axis was 10 to 80 degrees. The deviation of the optical axis depends on the constituent pixel pitch.

Range of the number of divisions of the drive electrodes in the pixel shifting operation: The elements to be made high in resolution as described above are
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 was synchronized with the vertical synchronizing signal, and 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 experiment here, it was found that the high resolution 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 structure: FIG. 23 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. The distance between the electrodes is required to 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 in the case of the unipolar cell. The liquid crystal alignment direction was set in consideration of the pixel shift direction.

Regarding the synchronizing 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 a 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. 24, 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 25
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. 26 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.

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.

For the resolution evaluation here, a signal from an NTSC resolution evaluation pattern (video signal pattern generator: Sony MTSG-1000) is input as video, and the resolution of black and white lines is determined by observation. did.

These high-resolution techniques can be used in any form such as direct-view type, reflection type, and projection type. this house,
27 to 29 show three examples of projection type displays incorporating the wobbling element according to the present invention. However, for simplification, the same reference numeral is given to a plurality of elements 3 and 4.

In the example of FIG. 27, the light from the halogen lamp 17 is led to the display element 2 as a backlight through the cold filter 43, and after the above-mentioned wobbling process, the lens system.
An image is projected from 44 to screen 45.

FIG. 28 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.

FIG. 29 shows a prism type display,
It is basically the same as that of FIG. 28 except that the light of each wavelength is combined via the dichroic prism 48.

The above-mentioned high resolution technique is applied in the visible light wavelength range because it is applied as a display.

The present invention is not limited to the display element 2 described above,
It is also applied to the case where the above-mentioned wobbling element 7 is arranged in the optical path that connects the image pickup device such as CCD including discrete pixels and the object. The same applies to the elements 7-1 to 7-n according to the present invention.

The image pickup device 71 shown in FIGS. 30 and 31 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 such as a CCD is used, for example, 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, β = 45
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 using the image pickup device, the object and the image pickup device
In the optical path connecting 53, the subject, the polarizer, the FLC element, the birefringent substrate, and the imaging element are arranged in this order. 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. 30 and 31, 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, goes out to the air layer again, and is irradiated to each pixel of the CCD image pickup device 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. 30, giving a deviation from the optical axis. At this time, there are almost no components other than the point a.

In the other switch state, since it is 45 + γ degrees, the polarization plane of the transmitted light rotates by 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. 50, 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 there is some leakage in the adjacent imaging pixels in the Y direction. Occurs. Therefore, in this case, the effect of shifting the pixels, which should have a high resolution, is slightly reduced.

FIG. 32 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.

In other words, for example, the pixels of the CCD image pickup device are discrete, and if there is no shift of the optical axis, a is
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, after 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.

A specific mounting example of the above-mentioned video camera of the cell: 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.

In the case of normal image pickup of visible light A semiconductor image pickup device such as a CCD image pickup 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 is shown in which an infrared cut filter (cuts a wavelength of 700 nm or more) 61 is combined with the pixel shift element. 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. 33, Fig. 34).

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 stacking 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 a component of 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. 35 shows an implementation example in which such a low-pass filter is not used, and FIG. 36 shows an implementation example in which the low-pass filter is used.
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. 37 shows a color separation camera system using three CCDs. However, CCD drive circuit,
The wobbling element drive circuit is omitted.

Imaging of Infrared Light By utilizing the near infrared light region of a semiconductor image pickup device such as a CCD image pickup device, it is possible to take an image of only the near infrared light region which cannot be sensed by human eyes. In this case, it is not necessary to intentionally insert an infrared cut filter.

In this case, in order 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, in FIG. 1, both wobbling elements to be laminated are rotated 90 degrees around the optical axis to be combined, and the rotation angle can be variously changed. In some cases, both elements may have the same angle with respect to the optical axis. Further, both elements may be placed in close contact with each other without being combined (that is, without being laminated), or may be arranged to face each other with a certain gap. Also, the number of combinations of elements may be changed appropriately.

Further, in FIG. 4 and FIG. 5, the polarity of the applied voltage in the state 1 and the state 2 of the element B can be reversed from that described above. Further, the rotation angle of the polarization plane by the phase modulation element 73 used in the example of FIG. 8 is not limited to 90 degrees, but 90 degrees ± 45 degrees.
It may be a degree.

Although all of the above-described embodiments are suitable for wobbling, the example shown in FIG. 8, for example, can be applied to optical applications other than wobbling.

In addition to the above-described liquid crystal element, the structure, material and shape of each component, assembling method and the like may be variously changed. The substrate is not limited to the glass plate and may be any other optically transparent material. Various liquid crystals can be adopted.

The object to which the present invention is applied includes, of course, the optical system such as the display device and the image pickup device described above and the wobbling element which can be incorporated in the system.

[0134]

As described above, the present invention provides at least one liquid crystal selected from a ferroelectric liquid crystal (FLC), an antiferroelectric liquid crystal (AFLC), and a smectic liquid crystal (SmA) exhibiting an electroclinic effect. Since the optical device is configured by a combination of a plurality of elements including a phase-modulating optical element in which is injected into the gap between the substrates and an optically transparent birefringent medium, The element can change the phase of light to shift the plane of polarization, and the birefringent medium can selectively refract incident light two-dimensionally (both vertically and horizontally). Therefore, wobbling can be effectively performed on the discrete pixels, the resolution can be improved, and the image quality can be improved.

In any of the liquid crystals such as the ferroelectric liquid crystal used for the phase modulation optical element, the direction of the liquid crystal director is easily changed by the action of the electric field, and the response speed is very fast. Can be sufficiently driven. Moreover, since it is a combination of a plurality of wobbling elements, the driving cycle thereof can be lengthened, and it becomes easy to support the video rate.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a wobbling element according to the present invention.

FIG. 2 is a table and a schematic view showing a switch state of the wobbling element, a pixel shift position, and a polarization direction after the shift.

FIG. 3 is a drive waveform diagram during wobbling by the wobbling element.

FIG. 4 is a table similar to FIG. 2 when the switch state of the wobbling element is changed.

FIG. 5 is a drive waveform diagram during the same wobbling.

FIG. 6 is a principle diagram for explaining the wobbling operation.

FIG. 7 is a schematic side view of another wobbling element.

FIG. 8 is a schematic perspective view of another wobbling element according to the present invention.

FIG. 9 is a table showing an operation of the wobbling element.

FIG. 10 is a schematic perspective view of another wobbling element according to the present invention.

FIG. 11 is a schematic perspective view and a side view of a specific example of the wobbling element.

FIG. 12 is a schematic perspective view of the wobbling element.

FIG. 13 is a schematic perspective view of still another wobbling element according to the present invention.

FIG. 14 is a schematic diagram of a display device to which the present invention is applicable, in state 1.

FIG. 15 is a schematic diagram of the same display device in a second state.

FIG. 16 is an explanatory diagram of a cone angle of a ferroelectric liquid crystal (FLC) used in the display device.

FIG. 17 is a schematic view of a specific example of the display device in each switch state.

FIG. 18 is a schematic diagram of a case where a normally white TN liquid crystal display element is used in the display device.

FIG. 19 is a schematic diagram of a case where a normally black TN liquid crystal display element is used in the display device.

FIG. 20 is a schematic diagram of a display device using a display element having a small degree of polarization.

FIG. 21 is a cross-sectional view of a liquid crystal cell as a phase modulation element using a FLC liquid crystal element.

FIG. 22 is an explanatory diagram of an optical axis shift due to a birefringent medium.

FIG. 23 is a schematic perspective view showing divided electrodes in a phase modulation element.

FIG. 24 is an explanatory diagram of an interlaced scanning method.

[Fig. 25] Fig. 25 is a waveform diagram of a synchronization signal in each field of the television.

FIG. 26 is a block diagram showing a connection relationship between respective elements of the display device.

FIG. 27 is a cross-sectional view of a display to which the display device is applied.

FIG. 28 is a cross-sectional view of another application example to a display.

FIG. 29 is a cross-sectional view of still another example of application to a display.

[Fig. 30] Fig. 30 is a schematic diagram in a state 1 of an imaging device to which the present invention can be applied.

FIG. 31 is a schematic diagram of the same imaging device in state 2.

FIG. 32 is a schematic diagram of a specific example of the imaging apparatus.

FIG. 33 is a schematic diagram of a mounted state of a crystal optical low-pass filter.

[Fig. 34] Fig. 34 is a principle diagram illustrating blurring caused by three crystal filters of the same.

FIG. 35 is a cross-sectional view of a mounting example of the imaging device.

FIG. 36 is a cross-sectional view of another mounting example.

FIG. 37 is a cross-sectional view of still another mounting example.

[Explanation of symbols]

1 ... (Liquid crystal optical) display device 2 ... (Liquid crystal) display element 3, 3-1 to 3-n ... Ferroelectric liquid crystal element 4, 4-1 to 4-n ... Birefringence Medium 5 ... Display pixel 6 ... Polarized light 7, 7-1 to 7-n ... Wobbling element (picture element shifting element) 8, 10, 10-1, 10-2, 10-3 ... Extraordinary optical axis 9 ... Polarization direction 13, 14 ... Transparent electrode 15 ... Liquid crystal 18, 19 ... Polarizing plate 20, 21 ... Transparent substrate 22, 23 ... Alignment film 50 ... Subject 53 ・ ・ ・ CCD element 61 ・ ・ ・ Infrared cut filter 64 ・ ・ ・ Optical low pass filter 70 ・ ・ ・ Polarizing screen 71 ・ ・ ・ Imaging device 73 ・ ・ ・ Phase modulator d, d / 2 ・ ・ ・ d / 2 ⁿ ... thickness

Front page continued (72) Inventor Yang Eiho 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Hidehiko Takanashi 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni Co., Ltd. (72) Eriko Matsui Eriko Matsui 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Nobe Kataoka 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation Within

Claims (13)

[Claims] 1. A plurality of optically transparent substrates provided with an optically transparent electrode and an alignment film in this order are arranged facing each other at a predetermined gap on the side of the electrode and the alignment film, A phase modulation optical element in which at least one liquid crystal selected from a ferroelectric liquid crystal, an antiferroelectric liquid crystal, and a smectic liquid crystal exhibiting an electroclinic effect is injected into the gap; and an optically transparent birefringence An optical device configured by combining a plurality of elements including a medium and; 2. A wobbling element in which a phase modulation optical element and a birefringent medium are sequentially arranged in an optical path between a display element and an observation position which are to be made high in resolution or between an object and an image pickup element. 2. The optical device according to claim 1, wherein a combination of the display elements or the image pickup elements is wobbled one-dimensionally or two-dimensionally. 3. When light from a display element or an object to be high-resolution is not polarized, an element for giving polarization is provided in an optical path between the combination of the wobbling element and the display element or the object. The optical device according to claim 2, wherein the optical device is arranged. 4. The optical device according to claim 1, wherein the wobbling element is driven at a video rate. 5. The n-number (n is an integer) wobbling element is combined so that the deviation of the optical axis of the birefringent medium extends over 2 ⁿ points. Optical device. 6. A polarization plane of 90 ° ± 45 in the optical path between the combination of the wobbling elements and the observation position or the image pickup element.
6. A phase modulation element for rotating the phase is arranged, and the phase modulation element is configured to align the polarization planes during wobbling by switching the phase modulation element in synchronization with a change in the polarization direction during wobbling. The optical device according to item 1. 7. The optical device according to claim 6, wherein a polarizing screen is arranged on the light emission side of the combination of wobbling elements. 8. The optical device according to claim 6, wherein the liquid crystal used for the phase modulation element is a chiral smectic liquid crystal. 9. The driving cycle of each phase modulation optical element in a combination of wobbling elements is set to be at least 4 times the wobbling cycle.
The optical device according to any one of to 8. 10. When driving each phase modulation optical element of two wobbling elements combined with each other, the drive cycle of each phase modulation optical element is set to four times the wobbling cycle, and the phases of the drive cycle are mutually set. The optical device according to claim 9, wherein the optical device is shifted by 90 degrees. 11. The birefringent medium is composed of a transparent substrate that shifts the optical axis depending on the polarization direction of incident light, and is arranged so as to have an equivalent uniaxial extraordinary optical axis component in the wobbling direction. The optical device according to claim 1. 12. The extraordinary optical axis of the birefringent medium forms an angle of 10 to 80 degrees with respect to the optical axis of the wobbling optical system.
Optical device described in 11. 13. The birefringent medium comprises quartz.
Item 11. The optical device according to any one of items 11.