JPH01169429A - Liquid crystal shutter - Google Patents

Abstract

PURPOSE:To improve the contrast by providing a second liquid crystal layer for holding a liquid crystal molecule in an oriented stage which is determined in advance. CONSTITUTION:A liquid crystal shutter body is constituted of a shutter liquid crystal layer 1 being a first liquid crystal layer, an incident side polarizing plate 3 and an emitting side polarizing plate 4. The incident side polarizing plate 3 is provided by turning its polarization axis direction 3a in the direction of about 45 deg. against the liquid crystal molecule orientation direction of the shutter liquid crystal layer 1, and the emitting side polarizing plate 4 is provided by allowing its polarization axis direction 4a to be roughly orthogonal to the polarization axis direction 3a. Also, a phase correcting liquid crystal layer 2 being the second liquid crystal layer for orienting the liquid crystal molecule in the direction being roughly orthogonal to the liquid crystal molecule orientation direction of the shutter liquid crystal layer 1, and also, holding this liquid crystal molecule in an oriented state which is determined in advance is placed between the emitting side polarizing plate 4, and the shutter liquid crystal layer 1. In such a way, a leakage light at the time of shutter OFF is reduced, and the contrast is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal shutter that uses liquid crystal to transmit and block light.

[Conventional technology]

In recent years, liquid crystal shutters that use liquid crystal to transmit and block light have come to be used as light control elements in electrophotographic printers and the like.

Conventionally, TN type and GH type liquid crystal shutters are known as this type of liquid crystal shutter, but in both TN type and GH type liquid crystal optical elements, the liquid crystal molecules are oriented with respect to the substrate surface. Since it transmits and blocks light by controlling the vertical and horizontal states, the response is poor and the contrast is low. Therefore, electrophotographic printers that use this liquid crystal shutter as a light control element have a problem of slow printing speed.

Therefore, recently, it has been considered to use a liquid crystal shutter ladder using a birefringence control mode (hereinafter referred to as a birefringence type liquid crystal shutter) as a light control element in a photoelectrophotographic printer or the like.

This birefringent liquid crystal shutter basically has a pair of polarizing plates placed on the incident side and output side of a liquid crystal layer in which liquid crystal molecules are oriented in one direction, and the liquid crystal layer has a pair of transparent It is constructed by filling liquid crystal between the substrates. In addition, transparent electrodes with a predetermined pattern are formed on the opposing surfaces of the pair of transparent substrates, and the electrode forming surfaces are provided with an orientation for horizontally aligning the liquid crystal molecules of the liquid crystal filled between the two substrates. A treated film (horizontal alignment film obtained by rubbing an organic alignment film such as polyimide) is provided, and liquid crystal molecules are aligned in the alignment direction (rubbing direction) of the alignment film on one substrate surface and on the other substrate surface. By making the directions of the alignment treatment of the alignment treatment films exactly opposite to each other (parallel and opposite directions), homogeneous alignment is achieved in one direction along the orientation treatment direction. The part where the electrodes of both substrates face each other is used as a shutter section to control the transmission of light, and the liquid crystal molecules in this shutter section are aligned in an electric field applied between the electrodes of both substrates. It's about to be controlled. Further, among a pair of polarizing plates disposed on the incident side and the output side of the liquid crystal layer, the polarizing plate on the incident side has its polarization axis direction approximately 45 degrees with respect to the liquid crystal molecule orientation direction of the liquid crystal layer. The polarizing plate on the output side has its polarization axis direction almost perpendicular to the polarization axis direction of the polarizing plate on the input side (intersects at an angle of approximately 45° with respect to the orientation direction of liquid crystal molecules in the liquid crystal layer).
Let it be.

This birefringent liquid crystal shutter uses the pair of polarizing plates to control light transmission by selectively controlling the alignment state of liquid crystal molecules by applying an electric field and changing the birefringence index of the liquid crystal layer. When the liquid crystal molecules are homeotropically aligned by applying a shutter OFF electric field, the light passing through the liquid crystal layer is blocked by the exit side polarizing plate, and the liquid crystal molecules are changed from the homeotropic alignment state to the initial alignment by applying the shutter ON electric field. When returning to state B (homogeneous alignment state), when the liquid crystal molecules become inclined alignment state with a certain tilt angle in the process, the light passing through the liquid crystal layer is transmitted through the output side polarizing plate due to the birefringence effect. A local maximum value of the intensity appears. Therefore, by applying to the liquid crystal an OFF electric field to bring the liquid crystal molecules into a homeotropic orientation state and an ONWi field to bring them into an inclined orientation state, the liquid crystal shutter transmits and blocks light. This birefringent liquid crystal shutter transmits light by controlling the alignment state of liquid crystal molecules into a homeotropic alignment state and an inclined alignment state.
Since it is a blocking device, the alignment state of liquid crystal molecules can be changed between a shutter ON (light transmission) state and a shutter OFF (light blocking) state.
The time required to change the state is very short, and the contrast is higher than that of TN type and GH type liquid crystal shutters. Therefore, since it has excellent responsiveness, if this birefringent liquid crystal shutter is used as a light control element of a photoelectrophotographic printer, the printer speed can be increased.

[The problem that the invention attempts to solve]

However, in the above-mentioned birefringent liquid crystal shutter, if the liquid crystal molecules that are homeotropically aligned by the application of the shutter OFF electric field stand up perpendicular to the substrate surface, there is almost no light leakage, but in reality, the liquid crystal molecules are completely vertical. does not rise, so there is light leakage when the shutter is off.

Therefore, there is a problem in that the contrast between when the shutter is ON and when the shutter is OFF cannot be made sufficiently high. This is because the alignment regulating force of the horizontal alignment treatment film provided on the substrate surface is always acting on the liquid crystal molecules. There is a phase shift between the oscillating light along the optical axis direction (molecule long axis direction), that is, the extraordinary light component, and the oscillating light in the direction perpendicular to this, that is, the ordinary light component, and the light exiting the liquid crystal layer becomes elliptically polarized light. Therefore, out of the light, the light in the vibration direction along the polarization axis direction of the output side polarizing plate is transmitted through the output side polarizing plate and causes light leakage. Note that by increasing the driving voltage when the shutter is OFF and applying a strong electric field to the liquid crystal layer, the alignment state of the liquid crystal molecules can be brought closer to vertical alignment.
Even if the drive voltage is increased in this way, it is difficult to align the liquid crystal molecules perfectly vertically, and in order to increase the drive voltage, a drive circuit with a high breakdown voltage must be used. This not only complicates the process, but also creates a new problem in that semiconductor integrated circuits cannot be used in the drive circuit.

The present invention has been made in view of the above circumstances, and its purpose is to improve contrast by reducing light leakage when the shutter is OFF without increasing the drive voltage when the shutter is OFF. The object of the present invention is to provide a birefringent liquid crystal shutter that can be used.

[Means to solve problems]

In order to achieve the above object, the present invention has a first liquid crystal layer in which the orientation direction of liquid crystal molecules is determined and the orientation state of the liquid crystal molecules is selectively controlled. approximately 4 with respect to the liquid crystal molecule orientation direction of the first liquid crystal layer.
A first polarizing plate oriented in a direction of 5° and a second polarizing plate having a polarization axis direction substantially perpendicular to the polarization axis direction of the first polarizing plate are arranged, and any of the two polarizing plates is arranged. The orientation direction of liquid crystal molecules is determined in a direction substantially perpendicular to the orientation direction of liquid crystal molecules in the first liquid crystal layer between one side and the first liquid crystal layer, and the liquid crystal molecules are aligned in a predetermined orientation. A second liquid crystal layer is provided to maintain the state.

[Effect]

That is, the liquid crystal shutter of the present invention blocks the transmission of light using a first liquid crystal layer that selectively controls the alignment state of liquid crystal molecules, and first and second polarizing plates arranged on the incident side and output side of the first liquid crystal layer. In addition, a second liquid crystal layer is arranged between either one of the polarizing plates and the first liquid crystal layer, and the second liquid crystal layer allows the shutter to be 2 of the light that passes through the first liquid crystal layer when it is OFF
It is designed to correct the phase shift between the oscillating light component in the direction, that is, the ordinary light component and the extraordinary light component.
If the liquid crystal molecules of the liquid crystal layer are aligned in a direction almost perpendicular to the orientation direction of the liquid crystal molecules of the first liquid crystal layer and the liquid crystal molecules are maintained in a predetermined alignment state, no abnormality will occur in the first liquid crystal layer. The light becomes ordinary light in the second liquid crystal layer,
Since the light that is ordinary light in the first liquid crystal layer becomes extraordinary light in the second liquid crystal layer, there is a phase shift between the oscillating light components in two directions of the light that passes through the first liquid crystal layer when the shutter is OFF. , since the phase shifts of the oscillating light components in the two directions of the light transmitted through the second liquid crystal layer are opposite to each other, the first liquid crystal layer and the second liquid crystal layer
The light that has passed through both the liquid crystal layer and the liquid crystal layer becomes light (light that is close to linearly polarized light) with a small phase shift between the oscillating light components in the two directions, and this light hardly passes through the polarizing plate on the output side.

Therefore, according to this liquid crystal shutter, the shutter is turned off.
The contrast can be improved by reducing light leakage when the shutter is OFF without increasing the driving voltage. Note that the second liquid crystal layer may be provided on the incident side or the output side of the first liquid crystal layer, and the second liquid crystal layer may be provided on the incident side or the output side of the first liquid crystal layer.
When the liquid crystal layer is provided on the incident side of the liquid crystal layer, the light whose phase shift of the oscillating light components in two directions in the first liquid crystal layer is corrected in advance enters the first liquid crystal layer, and the second liquid crystal layer is When provided on the output side of the first liquid crystal layer, the phase shift of the oscillating light components in two directions of the light transmitted through the first liquid crystal layer is corrected in the second liquid crystal layer.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

Figure 1 shows the basic configuration of a liquid crystal shutter. In the figure, 1 is a first liquid crystal layer (hereinafter referred to as a shutter liquid crystal layer) that aligns liquid crystal molecules in one direction and selectively controls the alignment state of the liquid crystal molecules. ), 3 and 4 are polarizing plates arranged on the incident side and the output side of the shutter liquid crystal layer 1, and the liquid crystal shutter main body is formed by the shutter liquid crystal layer 1, the incident side polarizing plate 3, and the output side polarizing plate 4. It is configured. The incident side polarizing plate 3 is provided with its polarization axis direction 3a oriented at approximately 45° with respect to the liquid crystal molecule orientation direction of the shutter liquid crystal layer 1, and the output side polarizing plate 4 is provided with its polarization axis direction 4a oriented at approximately 45° with respect to the liquid crystal molecule orientation direction of the shutter liquid crystal layer 1. It is provided substantially perpendicular to the polarization axis direction 3a of the incident side polarizing plate 3. Further, reference numeral 2 denotes a second liquid crystal layer (hereinafter referred to as a phase correction liquid crystal layer) which orients liquid crystal molecules in a direction substantially perpendicular to the liquid crystal molecule orientation direction of the shutter liquid crystal layer 1 and maintains the liquid crystal molecules in a predetermined orientation state. This phase correction liquid crystal layer 2 is disposed between the exit side polarizing plate 3 and the shutter liquid crystal layer 1. FIG. 2 shows the orientation directions of liquid crystal molecules in the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2, and the polarization axis directions 3a and 4a of the incident side and output side polarizing plates 3.4, where 1a indicates the shutter liquid crystal layer 1
2a indicates the liquid crystal molecule alignment direction of the phase correction liquid crystal layer 2.

To explain the specific structure of this liquid crystal shutter, FIG. 3 is an exploded view of the liquid crystal shutter, and FIGS. 4 and 5 are cross-sectional views along the vertical and horizontal directions of the liquid crystal shutter. The layer 1 and the phase correction liquid crystal layer 2 are each constructed by filling a pair of transparent substrates with liquid crystal. In this embodiment, the output side substrate of the shutter liquid crystal layer 1 and the input side substrate of the phase correction liquid crystal layer 2 are shared by one substrate. That is, in FIGS. 3 to 5, 1
1 is an upper substrate which is an incident side substrate of the shutter liquid crystal layer 1;
13 is an intermediate substrate that serves as the output side substrate of the shutter liquid crystal layer 1 and the input side substrate of the phase correction liquid crystal layer 2; 13 is a lower substrate that is the output side substrate of the phase correction liquid crystal layer 2; and these three substrates 11. 12 and 13 are laminated and bonded via a frame-shaped sealing material 14 and 15.

A large-area transparent common electrode 16 is formed on the lower surface (the surface facing the intermediate substrate 12) of the upper substrate 11, which is the input side substrate of the shutter liquid crystal layer 1, and the upper surface of the intermediate substrate 12, which is the output side substrate. A plurality of transparent segment electrodes 17.17 are formed on the surface facing the upper substrate 11, and the portions where the common electrode 16 and each segment electrode 17.17 are opposed are respectively configured to transmit and block light. This is the shutter area for controlling the Although the number of segment electrodes 17 is shown as two for convenience in the figure, the required number of segment electrodes 17 are formed in a predetermined pattern. 16a
, 17a are the common electrode 16 and each segment electrode 17.
．． These are drive circuit connection terminal portions led out from 17 to the side edges of each substrate 11 and 12, respectively. Further, the upper substrate 11
In order to horizontally orient the liquid crystal molecules a of the liquid crystal filled between the two plates 11 and 12 over the entire area surrounded by the sealing material 14 on the opposing surface (electrode forming surface) of the intermediate substrate 12 and the intermediate substrate 12. Orientation treatment films 18 and 19 are provided. The alignment films 18 and 19 are formed by forming an organic alignment film such as polyimide on the surface of the substrate 11 and 12 and rubbing the surface of the alignment film. The rubbing direction 18a and the rubbing direction 19a of the alignment film 19 on the intermediate substrate 12 side are the third
Directly opposite each other (parallel and opposite directions) as shown in the figure
It is said that This alignment film rubbing direction 18a, 19a
is the width direction of the substrate, that is, the X-axis direction in FIGS. 1 and 2. Therefore, the liquid crystal molecules a of the shutter liquid crystal layer 1 are aligned in the X-axis direction as shown in FIG. It is homogeneously oriented in one direction along the 9th axis.

゛ On the other hand, the lower surface (opposite surface to the lower substrate 13) of the intermediate substrate 12, which is the input side substrate of the phase correction liquid crystal layer 2, and the upper surface (opposite surface to the intermediate substrate 12) of the lower substrate 13, which is the output side substrate. ) have large-area transparent electrodes 20.
21 is formed.

Reference numerals 29a and 21a are drive circuit connection terminal portions led out from the picture electrodes 20.21 to the side edges of each substrate 12.13, respectively. Further, alignment treatment films 22 and 23 are also provided on the opposing surfaces (electrode forming surfaces) of the intermediate substrate 12 and the lower substrate 13 over the entire area surrounded by the sealing material 15,
The alignment films 22 and 23 are also formed by forming an organic alignment film such as polyimide on the surface of the substrate 12 and 13 and rubbing the surface of the alignment film. And intermediate board 1
A rubbing direction 22a of the alignment film 22 on the second side and a rubbing direction 23a of the alignment film 23 on the lower substrate 13 side.
As shown in FIG. 3, these are exactly opposite directions to each other, and moreover, the rubbing directions 18a of the alignment films 18 and 19 of the shutter liquid crystal layer 1.

19a, that is, the Y-axis direction (vertical width direction of the substrate) in FIG. They are homogeneously oriented in one direction along the Y-axis direction.

The incident side polarizing plate 3 and the exit side polarizing plate 4 are the outer surface (upper surface) of the upper substrate 11 which is the incident side substrate of the shutter liquid crystal layer 1 and the lower substrate which is the output side substrate of the phase correction liquid crystal layer 2. 1
The polarization axes 3a and 4a of both polarizing plates 3 and 4 are substantially orthogonal to each other, and the liquid crystal molecule orientation of the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2 is It is oriented at approximately 45° with respect to directions 1a and 2a.

In addition, the liquid crystals of the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2 are the same liquid crystal, and this liquid crystal is used for two-frequency drive with the characteristic that the dielectric anisotropy is reversed in high frequency and low frequency electric fields. It is said to be a nematic liquid crystal.

The liquid crystal shutter having the above structure applies an alternating electric field of a constant voltage to the phase correction liquid crystal layer 2, and causes the liquid crystal molecules a of the phase correction liquid crystal layer 2 to rise in a predetermined manner as shown in FIGS. 6 to 9. The shutter liquid crystal layer 1 is held in an oriented state, and a two-frequency drive electric field of a high frequency electric field and a low frequency electric field is applied to the shutter liquid crystal layer 1 to turn the shutter section ON-OFF.A low frequency electric field is applied to the shutter liquid crystal layer 1. Then, since the dielectric anisotropy of the nematic liquid crystal for two-frequency driving is positive in a low-frequency electric field, the liquid crystal molecules a between the electrodes 16 and 17 rise from the initial alignment state (homogeneous alignment state), and the liquid crystal molecules a
is in an alignment state where it stands up at an angle close to perpendicular to the substrate 11, 12 plane, and therefore the light transmitted through the shutter liquid crystal layer 1 is blocked by the exit side polarizing plate 4, and the shutter section is in an OFF state in which no light is transmitted. Become. In addition, the shutter liquid crystal layer 1
When a high-frequency electric field is applied instead of a low-frequency electric field, the dielectric anisotropy of the nematic liquid crystal for dual-frequency driving is negative in the high-frequency electric field, so the liquid crystal molecules a, which were oriented to stand up when the shutter is OFF, return to the initial alignment state. Trying to go back. In this case, as the liquid crystal molecule a falls down, the birefringence of the liquid crystal layer 1 changes moment by moment as the inclination of the liquid crystal molecule a changes, and as a result, the light transmitted through the shutter liquid crystal layer 1 changes from moment to moment. At this time, when the tilt angle of the liquid crystal molecules a approaches a certain angle, the light transmitted through the output side polarizing plate 4 becomes a bright state exhibiting approximately flat spectral characteristics. Therefore, if the application time is set so that the application of the high-frequency electric field is cut off at this time, and the state showing the above-mentioned flat spectral characteristics is used as the shutter ON state, the shutter section is turned 0N-OFF and the light is transmitted and blocked. can be controlled.

In this case, the transmitted light intensity I of the light vertically incident on the liquid crystal shutter is given by the following equation.

1-I□ 5in22φ5in2 (πΔnr d/λ)
--- (1) Here, IO = transmitted light intensity φ determined by the transmittance of the polarizing plate: the difference between the optical axis direction of the liquid crystal molecules in the initial alignment state and the polarization axis (transmission axis or absorption axis) direction of the polarizing plate. Angle Δnr: Birefringence that depends on the angle θ between the normal direction of the substrate surface and the optical axis direction of the liquid crystal molecules λ: Wavelength of incident light d: Layer thickness of the liquid crystal layer Note that the birefringence Δnr is Although it changes depending on θ, if the refractive index n/ and n of the liquid crystal are known, it can be calculated using the following equation using θ as a parameter.

6 and 7 show the shutter OFF state in which the liquid crystal molecules a of the shutter liquid crystal layer 1 are oriented vertically, and FIGS. 8 and 9 show the liquid crystal molecules a of the shutter liquid crystal layer 1 with the tilted orientation. The oriented shutter ON state is shown. Note that in FIGS. 7 and 9, the liquid crystal molecules a of the shutter liquid crystal layer 1 are shown vertically, but the liquid crystal molecules a oriented in the directions shown in FIGS. 6 and 8 are shown in the horizontal direction. I'm watching from It's for a reason.

By the way, when a shutter OFF electric field, that is, a low frequency electric field is applied to the shutter liquid crystal layer 1, there is no particular problem if the liquid crystal molecules a of the shutter liquid crystal layer 1 are completely vertically raised and aligned, but in reality, the liquid crystal molecules a is the alignment treatment film 18.1
9, the orientation control force of the shutter liquid crystal layer 1 causes the light to be not perfectly vertical, so as explained in the [Problems to be Solved by the Invention] section, the ordinary light component of the light that passes through the shutter liquid crystal layer 1 and the extraordinary light component are separated. A phase shift occurs between the components and the light exiting the shutter liquid crystal layer 1 becomes elliptically polarized light, and among the light, the light in the vibration direction along the polarization axis direction 4a of the output side polarizing plate 4 is transmitted to the output side polarizing plate 4. will pass through, causing light leakage.

Therefore, in this liquid crystal shutter, as described above, liquid crystal molecules a are aligned between the shutter liquid crystal layer 1 and the exit side polarizing plate 4 in a direction substantially perpendicular to the liquid crystal molecule orientation direction 1a of the shutter liquid crystal layer 1. By arranging the phase correction liquid crystal layer 2 and maintaining the liquid crystal molecules a of the phase correction liquid crystal layer 2 in a predetermined rising alignment state, the ordinary light component of the light that passes through the shutter liquid crystal layer 1 when the shutter is turned off is A phase correction liquid crystal layer 2 corrects the phase shift between the normal light component and the abnormal light component.

The phase shift between the ordinary light component and the extraordinary light component in the shutter liquid crystal layer 1 and the correction of the phase shift by the phase correction liquid crystal layer 2 will be explained with reference to FIG.

Focusing on the light of one wavelength among the wavelengths of light incident on the liquid crystal shutter, and considering the case where this light A propagates through the liquid crystal shutter in the OFF state, the light that has passed through the incident side polarizing plate 3 is The light enters the shutter liquid crystal layer 1 as linearly polarized light along the polarization axis direction 3a of the side polarizing plate 3, that is, in the direction of C45° with respect to the X and Y axes. In FIG. 1, Aa indicates the polarization direction of light that has passed through the incident side polarizing plate 3. The liquid crystal molecules a of the shutter liquid crystal layer 1 are not completely aligned perpendicularly even when the shutter OFF electric field (low frequency electric field) is applied as described above, and the liquid crystal molecules a of the shutter liquid crystal layer 1 are not aligned completely perpendicularly to the normal direction of the substrate surface. Since the shutter liquid crystal layer 1 is tilted by an angle θX, the light incident on the shutter liquid crystal layer 1 is incident obliquely to the tilt direction of the liquid crystal molecule a, that is, the optical axis direction (molecule long axis direction) of the liquid crystal molecule a. In this way, the propagation of the light incident obliquely with respect to the tilt direction of the liquid crystal molecule a is converted into X-axis component light Ax that vibrates in the X-axis direction.
and Y-axis component light A) that vibrates in the Y-axis direction perpendicular to this.
Considering the shutter liquid crystal layer 1 separately,
The Y-axis component light Ay propagates in the liquid crystal layer as ordinary light and the X-axis component light Ax as extraordinary light. Therefore, since the Y-axis component light Ay travels straight through the liquid crystal layer 1 without being refracted, and the X-axis component light Ax is refracted and travels through the liquid crystal layer 1, the optical path length of the X-axis component light Ax in the liquid crystal layer 1 becomes longer. . Therefore, shutter liquid crystal layer 1
The X-axis component light Ax is smaller than the Y-axis component light Ay due to the
The light is delayed in phase by Therefore, the light obtained by combining the X-axis component light Ax and the Y-axis component light Ay becomes elliptically polarized light Ab as shown in the figure, and if this elliptically polarized light Ab is directly input to the output side polarizing plate 4, light leakage will occur. do. However, in the liquid crystal shutter described above, since the phase correction liquid crystal layer 2 is disposed between the shutter liquid crystal layer 1 and the exit side polarizing plate 4, the elliptically polarized light Ab exiting the shutter liquid crystal layer 1 is transferred to the phase correction liquid crystal layer 2. incident on . The liquid crystal molecules a of the phase correction liquid crystal layer 2 are aligned in a direction substantially perpendicular to the liquid crystal molecule alignment direction 1a of the shutter liquid crystal layer 1, and are in a predetermined rising alignment state, that is, in the normal direction to the substrate surface. Y
Since the direction is maintained at an angle θy in the axial direction, in the phase correction liquid crystal layer 2, the X-axis component light Ax of the incident light is ordinary light, and the Y-axis component light Ay is extraordinary light, which travels through the liquid crystal layer. propagate. Therefore, in the phase correction liquid crystal layer 2, the X-axis component light A
x travels straight, and the Y-axis component light Ay is refracted and travels.As a result, the X-axis component light A generated in the shutter liquid crystal layer 1
The phase shift between the x and Y-axis component light Ay is corrected by the phase correction liquid crystal layer 2.
Corrected in .

Note that the rising orientation angle θy of the liquid crystal molecules a in the phase correction liquid crystal MI2 is determined by the amount of phase delay of the Y-axis component light Ay in the phase correction liquid crystal layer 2 and the amount of phase delay of the X-axis component light Ax in the shutter liquid crystal layer 1. δ may be selected to be equal to δ. If this is done, the light that exits the phase correction liquid crystal layer 2 (the light that is a combination of the X-axis component light Ax and the Y-axis component light Ay) will be polarized light on the incident side. The light becomes linearly polarized light along the polarization axis direction 3a of the plate 3 and enters the output side polarizing plate 4. In FIG. 1, Ac indicates the polarization direction of the light that exits the phase correction liquid crystal layer 2, and the polarization direction of this light is approximately perpendicular to the polarization axis direction 4a of the output side polarizing plate 4. Therefore, almost no light passes through the output side polarizing plate 4, so almost no light leaks.

Note that the phase delay amount δ of the X-axis component light Ax in the shutter liquid crystal layer 1 depends on the alignment state of the liquid crystal molecules a in the shutter liquid crystal layer 1, but in the case of a liquid crystal shutter in which the shutter liquid crystal layer 1 is statically driven, , since the rising orientation angle θX of the liquid crystal molecules a in the shutter liquid crystal layer 1 can be considered to be almost constant when the shutter is OFF, in the case of a statically driven liquid crystal shutter, the rising orientation angle θX of the liquid crystal molecules a in the phase correction liquid crystal layer 2 The electric field applied to the phase correction liquid crystal layer 2 may be set so that θy is the same as the rising orientation angle θX of the liquid crystal molecules a of the shutter liquid crystal layer 1. However, this is the case where the layer thicknesses (cell gaps) of the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2 are equal, and the liquid crystals of both liquid crystal layers 1 and 2 are the same liquid crystal. Even if the layer thickness and liquid crystal used are different, the electric field applied to the phase correction liquid crystal layer 2 can be set to various values, the amount of light leakage when the shutter is OFF is measured, and the electric field applied to the phase correction liquid crystal layer 2 can be adjusted based on this actual measurement value. By setting this, you can reduce the amount of light leakage.

In addition, when the liquid crystal shutter is dynamically driven, the waveform of the electric field applied to the shutter liquid crystal layer 1 changes, so even when the shutter is OFF, the rising orientation angle θX of the liquid crystal molecules a of the shutter liquid crystal layer 1 changes. Since it changes within a certain range, the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2
Even if the layer thicknesses are equal and the liquid crystals in both liquid crystal layers 1 and 2 are the same, it is not possible to simply determine the rising orientation angle θy of the liquid crystal molecules a in the phase correction liquid crystal layer 2. As described above, the electric field applied to the phase correction liquid crystal layer 2 is varied to measure the amount of light leakage when the shutter is OFF,
Based on this measured value, the electric field applied to the phase correction liquid crystal layer 2 may be set to a value that reduces the amount of light leakage.

Furthermore, in the above liquid crystal shutter, even when the shutter is in the ON state, the light transmitted through the shutter liquid crystal layer 1 is transmitted to the phase correction liquid crystal layer 2.
, the light transmittance when the shutter is ON is reduced to some extent compared to a liquid crystal shutter that does not include the phase correction liquid crystal layer 2, but the liquid crystal molecules a of the phase correction liquid crystal layer 2 are Therefore, since the liquid crystal molecules a of the shutter liquid crystal layer 1 are oriented at an angle that is the same as or close to the rising orientation angle θX in the shutter OFF state, that is, an angle that is close to vertical, the shutter is turned on by this phase correction liquid crystal layer 2. The decrease in light transmittance when the shutter is turned off is extremely small, and compared to this, the degree of decrease in light leakage when the shutter is OFF is much greater. Compared to conventional liquid crystal shutters that do not have a conventional liquid crystal shutter, the contrast between when the shutter is ON and when the shutter is OFF can be greatly improved.

Next, regarding the above liquid crystal shutter, the shutter liquid crystal layer 1 is driven by static driving to turn the shutter section into 0N-0.
The results of measuring the amount of transmitted light in the case of FF will be explained.

Note that here, the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2 are
As a liquid crystal, it has the following characteristics: N-1 point: 153.6°C Viscosity: 85.1 cP (at 30°C) Refractive index: nz = 1.648 n4-1.499 Δn = 0.149 (at 23°C, 546 nm) A nematic liquid crystal for two-frequency drive was used. Figure 10 shows this nematic liquid crystal for dual frequency drive.
It shows the frequency characteristics of dielectric anisotropy (Δε).

11 and 12 show that a rectangular wave electric field vL of 100 Hz is applied to the phase correction liquid crystal layer 2 (layer thickness 4.87 μm) of the liquid crystal shutter, and the shutter liquid crystal layer 1 (layer thickness 4.90 μm) is
Figure 11 shows the distribution characteristics of the amount of transmitted light when a direct current electric field VDC is applied to the shutter liquid crystal layer 1 (mIL). The amount of transmitted light when the shutter is ON and when Voc=10V is applied as an electric field and the electric field applied to the phase correction liquid crystal layer 2 is VL-gV, ML-15V, and VL-20V. Shutter OFF
In this case, when the electric field applied to the phase correction liquid crystal layer 2 was set to VL#8V, the amount of transmitted light when the shutter was OFF was almost 0.

Furthermore, in FIG. 12, the shutter ON electric field is set in the shutter liquid crystal layer 1 and tl''Voc -6,5Vs 'J+ Ivy O
When VDC-15V is applied as the FF electric field and the electric field applied to the phase correction liquid crystal layer 2 is set to VL-8V, and when VL-
The results show the amount of transmitted light when the shutter is ON and the amount of transmitted light when the shutter is OFF for the cases of 13V and VL-20V. In this case, the electric field applied to the phase correction liquid crystal layer 2 is When setting VL-13V,
The amount of transmitted light when the shutter was OFF was almost zero.

Next, a second embodiment of the present invention will be described with reference to FIGS. 13 to 19. The liquid crystal shutter of this embodiment is used as a light control element of an electrophotographic printer, and its configuration is as follows.

That is, FIG. 13 shows an exploded view of the liquid crystal shutter, and in the figure, 31, 32, and 33 are three horizontally long transparent substrates, an upper substrate 31, an intermediate substrate 32, and an intermediate substrate 3.
2 and the lower substrate 33 are each bonded to each other with a predetermined interval maintained therebetween using a horizontally long frame-shaped sealing material (not shown). Among these substrates 31, 32, 33, the upper substrate 31 is the entrance side substrate of the shutter liquid crystal layer 1, and the intermediate substrate 32 is the substrate on the entrance side of the shutter liquid crystal layer 1.
The lower substrate 33 serves as the output side substrate of the phase correction liquid crystal layer 2 and the input side substrate of the phase correction liquid crystal layer 2, and the shutter liquid crystal layer 1 serves as the upper substrate 31 and the intermediate substrate 32. The phase correction liquid crystal layer 2 is constructed by filling a space between an intermediate substrate 32 and a lower substrate 33 with liquid crystal.

Then, an upper substrate 3 which is the incident side substrate of the shutter liquid crystal layer 1
Two strip-shaped common electrodes (transparent electrodes) 34a are provided on the lower surface of the substrate 1 (the surface facing the intermediate substrate 32).

34b is formed over the entire length of the substrate, and the upper surface of the intermediate substrate 32 which is the output side substrate (the surface facing the upper substrate 31)
, a large number of transparent segment electrodes 35 are arranged at close intervals in the length direction of the common electrodes 34a and 34b. Moreover, the segment electrode 35... is the first common electrode 34 of the two common electrodes.
a first shutter electrode portion 35a facing the second common electrode 34b; a second shutter electrode portion 35b facing the second common electrode 34b;
A lead wire portion 35c led out from either one of these shutter electrode portions 35a, 35b, and this lead wire portion 35.
The drive circuit connection terminal portions 35d of each segment electrode 35 are arranged alternately on both side edges of the intermediate substrate 32. ing. And common electrodes 34a, 34
b and each shutter electrode 35a of the segment electrode 35...
, 35b are opposed regions, respectively, serving as shutter regions for controlling transmission and blocking of light. Note that the first shutter electrode portion 3 of each segment electrode 35...
5a and the second shutter electrode part 35b are formed to be shifted by 1/2 of the width of the shutter electrode part in the length direction of the common electrode, so that the first row of shutters arranged along the first common electrode 34a area and the second common electrode 34
The shutter portion regions of the second row lined up along line b are arranged with a 1/2 pitch shift. Further, on the opposing surfaces (electrode forming surfaces) of the upper substrate 31 and the intermediate substrate 32, the both side plates 3 are provided over the entire area surrounded by the sealing material.
Alignment treatment films 36 and 37 are provided for horizontally aligning the liquid crystal molecules of the liquid crystal filled between 1 and 32.

On the other hand, the intermediate substrate 3 which is the incident side substrate of the phase correction liquid crystal layer 2
2 (the surface facing the lower substrate 33) and the upper surface of the lower substrate 33 (the surface facing the intermediate substrate 32) which is the emission side substrate.
Transparent electrodes 38 and 39 having an area that includes all the shutter regions of the shutter liquid crystal layer 1 are formed respectively, and the seals are also formed on the opposing surfaces (electrode formation surfaces) of the intermediate substrate 12 and the lower substrate 13. An alignment treatment film 40,41 is provided over the entire area surrounded by the material.

The above alignment films 36, 37 and 40, 41 are formed by forming an organic alignment film such as polyimide on the substrate 31, 32, 33 surface and rubbing the alignment film surface. The alignment treatment films 36 and 37 of layer 1 are
The rubbing process is performed in opposite directions along the length of the substrate.

Reference numerals 36a and 37a indicate the direction in which the alignment films 36 and 37 are covered. Further, the alignment treatment films 40 and 41 of the phase correction liquid crystal layer 2 are aligned in the rubbing direction 36a of the alignment treatment film of the shutter liquid crystal layer 1.

The rubbing direction is shown along a direction (substrate width direction) substantially perpendicular to 37a. Therefore, the liquid crystal molecules (not shown) of the shutter liquid crystal layer 1 are aligned in the alignment film 36.
The liquid crystal molecules (not shown) of the phase correction liquid crystal layer 2 are homogeneously aligned in one direction along the length direction of the substrate due to the alignment regulating force of the alignment treatment films 40 and 41. , are homogeneously aligned in a direction substantially perpendicular to the alignment direction of liquid crystal molecules in the shutter liquid crystal layer 1.

Reference numerals 42 and 43 denote incident-side and exit-side polarizing plates that together with the shutter liquid crystal layer 1 constitute a liquid crystal shutter body. The entrance side polarizing plate 42 and the exit side polarizing plate 43 are connected to the outer surface (upper surface) of the upper substrate 31, which is the entrance side substrate of the shutter liquid crystal layer 1, and
The phase correction liquid crystal layer 2 is bonded to the outer surface (lower surface) of the lower substrate 33 which is the output side substrate, and the input side polarizing plate 4
2 is arranged with its polarization axis direction 42a oriented at approximately 45 degrees with respect to the liquid crystal molecule alignment direction of the shutter liquid crystal layer 1, and the output side polarizing plate 43 is arranged with its polarization axis direction 43a oriented at an angle of approximately 45° with respect to the liquid crystal molecule orientation direction of the shutter liquid crystal layer 1. The polarization axis direction 42a is arranged substantially perpendicular to the polarization axis direction 42a.

Further, the liquid crystals of the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2 are the same liquid crystal, and this liquid crystal is a nematic liquid crystal for two-frequency driving.

In the liquid crystal shutter of this embodiment, an alternating electric field of a constant voltage is applied to the phase correction liquid crystal layer 2, and the liquid crystal molecules in the phase correction liquid crystal layer 2 are brought into a predetermined rising alignment state (nearly perpendicular to the substrate surface). The shutter liquid crystal layer 1 is maintained in an orientation state in which the orientation rises at an angle of
It is a device for FF, and the shutter area of the shutter liquid crystal layer 1 (common electrodes 34a, 34b and segment electrodes 35...
When a low frequency electric field is applied between the shutter electrodes 35a and 35b), the liquid crystal molecules in the shutter area become oriented to stand up at an angle close to vertical, and the shutter area becomes O
When the FF state is entered and a high-frequency electric field is applied instead of a low-frequency electric field to the shutter region of the shutter liquid crystal layer 1, the liquid crystal molecules that were oriented in a rising position when the shutter was turned off try to return to the initial alignment state, and the tilt angle of the liquid crystal molecules changes. When the angle of inclination approaches a certain angle, the shutter section is turned on.

Further, in the liquid crystal shutter having a large number of shutter parts as described above, in order to simplify the drive circuit by reducing the number of electrode terminals, the common electrode 34a of the shutter liquid crystal layer 1,
34b and segment electrodes 35... are formed as described above to perform dynamic driving. When dynamically driving the liquid crystal shutter in this way, the shutter section is set to 0N.
- Since the drive signal for turning off the shutter does not have a simple waveform, the angle of inclination of the liquid crystal molecules of the shutter liquid crystal layer 1, which are oriented to rise when the shutter is turned off, with respect to the normal to the substrate becomes thicker than in the case of static driving. Therefore, when the conventional liquid crystal shutter which is not equipped with the phase correction liquid crystal layer 2 is dynamically driven, the shutter OF
Although the leakage of light in the F state further increases, in the liquid crystal shutter described above, liquid crystal molecules are arranged between the shutter liquid crystal layer 1 and the exit side polarizing plate 43 in a direction substantially perpendicular to the liquid crystal molecule alignment direction of the shutter liquid crystal layer 1. Since the phase correction liquid crystal layer 2 is arranged in such a manner that the liquid crystal molecules in the phase correction liquid crystal layer 2 are maintained in a predetermined rising alignment state,
Similar to the first embodiment described above, the phase correction liquid crystal layer 2 can correct the phase shift between the ordinary light component and the extraordinary light component of the light that passes through the shutter liquid crystal layer 1 when the shutter is OFF.

In addition, when dynamically driving the liquid crystal shutter, since the waveform of the drive signal is not a simple waveform as described above, the orientation state of the liquid crystal molecules in the shutter liquid crystal layer 1 is different from the shutter O.
Since the amount of light leakage varies within a certain range both in the FF state and in the shutter ON state, the amount of light leakage in the shutter OFF state is not constant, but the amount of light leakage when the shutter is OFF can be measured with various values of the electric field applied to the phase correction liquid crystal layer 2. For example, the optimum value of the electric field applied to the phase correction liquid crystal layer 2 (the value that minimizes the amount of light leakage)
can be known.

14 and 15 respectively show the waveform of the drive voltage applied to the common electrode and the segment electrode of the shutter liquid crystal layer 1 and the waveform of the applied electric field applied to the shutter liquid crystal layer 1. The waveform for one frame (2.38 m5ec) is shown when the shutter liquid crystal layer 1 is driven by multiplexing at 1/2 duty. In FIGS. 14 and 15, C1 is '!' of the shutter liquid crystal layer 1. This is the voltage applied to the J1 common electrode 34a, and although the voltage applied to the second common electrode 34b is not shown, it has a waveform that is shifted by 172 frames from the first common electrode applied voltage c1. 81 to S4 are segment electrode applied voltages, and among these segment electrode applied voltages 81 to s4, so is the first shutter section using the first common electrode 34a and the second shutter section using the second common electrode 34b. s2 is the applied voltage when the first shutter section is turned on and the second shutter section is turned off. S3 is the applied voltage when the first shutter section is turned off and the second shutter section is turned on. , S4 is an applied voltage when both the first shutter section and the second shutter section are turned off. Further, the frequency of the high frequency voltage of the common electrode applied voltage c1 and the high frequency voltage of the segment electrode applied voltages 81 to s4 is 200 KHz, the frequency of the low frequency voltage is 4K11z, and the amplitude VOP of each drive voltage c1 and S1 to S4 is 25 V. It is.

T1 is the selection time (1,19m5ec), and T2 is the non-selection time (1,19J'm5ec). Also, the first
In Figure 4, T3-0. 19m5ec.

T4-0.375m5ec 5T5-0.25m5ec
.

Tb-0, 25m5ec, T7 mo, 5m5ec, and in Fig. 15, T3-0.24m5ec
%T4-0.08m5oc, T5-0.30m5e
c %T6-0. '38m5ec, T7-0.
19m5ec.

Ta = 0.32 m5ec. Further, in FIGS. 14 and 15, CI Sl and CI Sl .

c, -s3. C, -s4 is Sl in the segment electrode 35.
, Sl, S3. The electric field (the first common electrode 34
a and the first shutter electrode portion 35a of the segment electrode 35
For example, if an electric field with a waveform of C1-51 or C1-82 in Fig. 14 is applied to the liquid crystal in the first shutter section, → ÷ meeting current −
First, a high frequency electric field is applied to the liquid crystal to turn the shutter section on, this ON state is maintained in the absence of an electric field, and the next application of a low frequency electric field turns the shutter section off. During the subsequent non-selection time T2, either a superimposed electric field of a low-frequency electric field and a high-frequency electric field and a low-frequency electric field are repeatedly applied to the liquid crystal (in the case of CL-81), or a low-frequency electric field and no electric field are applied to the liquid crystal. An electric field is applied repeatedly with the electric field (in the case of C1-S1), and at this time, the shutter section maintains the OFF state. In addition, when an electric field with a waveform of C, -S3 or C, -84 in Fig. 14 is applied to the liquid crystal in the first shutter section, the liquid crystal first experiences a superimposed electric field of a low-frequency electric field and a high-frequency electric field, and a low-frequency electric field. is applied repeatedly to turn the shutter section off. In this case as well, during the non-selection time T2, the superimposed electric field and the low frequency electric field are repeatedly applied (C,
-S3) or by repeatedly applying a low frequency electric field and no electric field (C, -s4), the shutter section maintains the OFF state. Note that since the voltage applied to the second common electrode 34b has a waveform shifted by 1/2 frame from the voltage applied to the first common electrode c1, the liquid crystal layer of the second shutter section has the above-mentioned C.
1-51, cl-s21 c, s31 CI
An electric field with a waveform shifted by 1/2 frame from S4 is applied,
Therefore, the second shutter section is selected and turned ON or OFF when the first shutter section is not selected.

Figure 16 shows a 100Hz (7) rectangular wave electric field VL applied to the phase correction liquid crystal layer 2 (layer thickness 4.87 μm) of the liquid crystal shutter.
and shutter liquid crystal layer 1 (layer thickness 4.20 μm):
The electric fields of C1-8l and C4-84 in Figure 14 are
This shows the results of investigating the distribution characteristics of the amount of transmitted light of this liquid crystal shutter by applying it as an N electric field and a shutter OFF electric field.
.

When setting 15V, 18V, 25V (7) in 4 ways and measuring the amount of transmitted light when the shutter is 08 and the amount of transmitted light when the shutter is OFF for each case, it was found that the electric field vL applied to the phase correction liquid crystal layer 2 was 15V ~ In the case of 25V,
The amount of transmitted light when the shutter was OFF was approximately 0 or a value extremely close to 0. FIG. 18 shows the shutter liquid crystal layer 1 in the first
This shows the results of measuring the contrast CR at shutter 08 and when the shutter is OFF when driving with the driving electric fields CCr Sr and CI S4) shown in Figure 4, focusing on light with a wavelength of λ-550 nm. , when the electric field vL applied to the phase correction liquid crystal layer 2 is around 20V, the light leakage is the lowest when the shutter is OFF, and when the shutter is ON.
Since the amount of transmitted light is the highest in this state, if the electric field vL applied to the phase correction liquid crystal layer 2 is set to around 20V, the shutter will be 0.
The contrast CR can be maximized at 8 o'clock and when the shutter is OFF.

Further, FIG. 17 shows the phase correction liquid crystal H of the liquid crystal shutter.
2C layer thickness 4.87μ77Z) and 100Hz as above
A rectangular wave electric field vL is applied, and the shutter liquid crystal layer 1 (layer thickness 4
．． 20um)l: Figure 15 (7) C1-81 and C, -S
This figure shows the results of examining the distribution characteristics of the amount of transmitted light of this liquid crystal shutter by applying the electric field No. 4 as the shutter ON electric field and shutter OFF electric field. 18V, 25V, 30
When the amount of transmitted light when the shutter is 08 and the amount of transmitted light when the shutter is OFF was measured in each case with the setting as V15, it was found that the electric field applied to the phase correction liquid crystal layer 2 was set to VL-
When the voltage was 15 V to 30 V, the amount of transmitted light when the shutter was OFF was approximately 0 or a value extremely close to 0. 19th
The figure shows the driving electric field (C, -
Contrast c when driven with sl and Ct S4)
This figure shows the results of measuring R focusing on light with a wavelength of λ-550 nm as above, and in this case as well, when the electric field vL applied to the phase correction liquid crystal layer 2 is around 20 V, the shutter is in the OFF state. Since the light leakage is the smallest and the amount of transmitted light is the highest when the shutter is ON, the contrast CR can be maximized by setting the electric field vL applied to the phase correction liquid crystal layer 2 to around 20V.

That is, the liquid crystal shutter of the present invention blocks the transmission of light by the shutter liquid crystal layer 1 that selectively controls the alignment state of liquid crystal molecules, and the incident side and output side polarizing plates arranged on the incident side and output side of the shutter liquid crystal layer 1. A birefringent liquid crystal shutter body is constructed, and liquid crystal molecules are arranged between the exit side polarizing plate of the two polarizing plates and the shutter liquid crystal layer 1 in a direction substantially perpendicular to the liquid crystal molecule alignment direction of the shutter liquid crystal layer. A phase correction liquid crystal layer 2 that aligns and holds liquid crystal molecules in parentheses in a predetermined alignment state is disposed, and this phase correction liquid crystal layer 2
According to this liquid crystal shutter, the phase shift between the two-direction oscillating light components, that is, the ordinary light component and the extraordinary light component, of the light that passes through the shutter liquid crystal layer when the shutter is OFF is corrected. The contrast can be improved by reducing light leakage during the shutter QFF operation without increasing the drive voltage during the shutter QFF operation.

In the above embodiment, the phase correction liquid crystal layer 2 is disposed between the output side polarizing plate and the shutter liquid crystal layer 1. between the side polarizing plate and the shutter liquid crystal layer),
In this case, light whose phase has been corrected in advance between the vibration light components in two directions in the shutter liquid crystal layer (light whose phase has been shifted by the phase correction liquid crystal layer) enters the shutter liquid crystal layer, and this shutter liquid crystal layer The light has almost no phase shift when it exits. Further, in the above embodiment, a nematic liquid crystal for two-frequency driving is used as the liquid crystal, but this liquid crystal may be a normal nematic liquid crystal, and two sheets each of the shutter liquid crystal layer 1 and the phase correction liquid crystal layer 2 are used. These two are composed of independent cells filled with liquid crystal between two substrates.
Two cells may be stacked.

〔Effect of the invention〕

According to the liquid crystal shutter of the present invention, contrast can be improved by reducing light leakage when the shutter is OFF without increasing the driving voltage when the shutter is OFF.

[Brief explanation of the drawing]

1 to 12 show a first embodiment of the present invention, in which FIG. 1 is a basic configuration diagram of a liquid crystal shutter, and FIG. 2 is a liquid crystal molecule orientation direction of a shutter liquid crystal layer and a phase correction liquid crystal layer. Figure 3 shows the polarization axes of the incident and output polarizing plates.
The figure is an exploded perspective view of the liquid crystal shutter, and Figures 4 and 5 are cross-sectional views along the vertical and horizontal directions of the liquid crystal shutter.
6 and 7 are cross-sectional views along the vertical and horizontal directions of the liquid crystal shutter in the shutter OFF state;
9 and 9 are cross-sectional views along the length and width directions of the liquid crystal shutter in the shutter ON state, FIG. 10 is a characteristic diagram of the nematic liquid crystal for two-frequency drive, and FIGS. 11 and 12 are the respective views of the liquid crystal shutter. FIG. 3 is a distribution characteristic diagram of the amount of transmitted light. 13 to 19 show a second embodiment of the present invention, in which FIG. 13 is an exploded perspective view of the liquid crystal shutter, and FIGS. 14 and 15 show the voltage applied to the electrodes of the shutter liquid crystal layer, respectively. A waveform diagram of the driving voltage and the applied electric field applied to the shutter liquid crystal layer, FIG.
Figure 4 shows the distribution characteristic of the amount of transmitted light of the liquid crystal shutter when driven with the electric field, Figure 17 shows the distribution characteristic of the amount of transmitted light of the liquid crystal shutter when the shutter liquid crystal layer is driven with the electric field of Figure 15, and Figure 18 14 is a contrast diagram when the shutter liquid crystal layer is driven by the electric field shown in FIG. 14, and FIG. 19 is a contrast diagram when the shutter liquid crystal layer is driven by the electric field shown in FIG. 15. 1...Shutter liquid crystal layer (first liquid crystal layer), 1a...
Liquid crystal molecule alignment direction, 2... Phase correction liquid crystal layer (second liquid crystal layer), 2a... Liquid crystal molecule alignment direction, a... Liquid crystal molecule, 3, 42... Incident side polarizing plate, 3a, 42a...
Polarization axis direction, 4, 43... Output side polarizing plate, 4a. 43a...Polarization axis direction, 11.12.13, 31°3
2.33... Substrate, 16.34a, 34b/w Mon electrode, 17.35... Segment electrode, 18° 19.3
6.37...Alignment treatment film, 18a, 19B. 36a, 37B...Rubbing direction, 20, 21° 38.39...Electrode, 22.23, 40.41...
Orientation treatment film, 22a, 23a, 40a, 41a...rubbing treatment direction. Applicant's representative Patent attorney Takehiko Suzue Figure 13 Figure 2 Figure 3 Figure 4 Country Figure 6 Figure 5 Figure 7 Figure 14 Figure 15

Claims (1)

[Claims] The orientation direction of the liquid crystal molecules is determined, and the orientation state of the liquid crystal molecules is selectively controlled on the incident side and the output side of the first liquid crystal layer. a first polarizing plate oriented at approximately 45° to the direction;
A second polarizing plate having a polarization axis direction substantially perpendicular to the polarization axis direction of the first polarizing plate is disposed, and between either one of the polarizing plates and the first liquid crystal layer, A second liquid crystal layer is provided, the orientation direction of the liquid crystal molecules being determined in a direction substantially perpendicular to the orientation direction of the liquid crystal molecules in the first liquid crystal layer, and maintaining the liquid crystal molecules in a predetermined orientation state. Features a liquid crystal shutter.