JP2016118601A - Polarization change-over spectacle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarization change-over spectacle that provides an excellent field of vision in a situation where various reflection light and scattering light are present, and also causes wears to feel less fatigue.SOLUTION: A polarization change-over spectacle is such that a right lens comprises: a first liquid crystal cell and a second liquid crystal cell (liquid crystal cell 110) that cause linear polarization to be rotated at a prescribed twist angle when voltage is not applied; and a first polarizer and a second polarizer (polarizer 120) that are provided on a rear side of a travelling direction of light from an outside with respect to the first liquid crystal cell and the second liquid crystal cell, in which transmission axes of the first polarization and the second polarization are parallel, and the twist angles of the first liquid crystal cell and the second liquid crystal cell are identical. A control device 30 is configured so as to intermittently apply voltage of the same phase at a prescribed frequency.SELECTED DRAWING: Figure 3

Description

  The present invention relates to polarization-switching eyeglasses with improved visibility in vehicle driving, sports, and other situations where there is reflected light or scattered light.

  In general, sunglasses (polarized glasses) provided with a polarizing filter that removes a specific linearly polarized light component are used to remove unpleasant reflected light on the road surface and the sky in driving a car or the like (Patent Document 1). . Polarized glasses generally transmit light in the vertical direction in order to block the linearly polarized light on the horizontal polarization plane, assuming that light enters from above and that the incident light is reflected by a reflecting surface on a horizontal surface such as a road surface or water surface. Has an axis.

  In addition, polarized glasses may be used as glasses for viewing 3D images (Patent Document 2). Such polarized glasses have a right-eye lens and a left-eye lens, and the polarization transmission axes are orthogonal to each other, and are configured to alternately show the right-eye image and the left-eye image to the viewer. Yes. In addition to polarizers, there are also liquid crystal glasses configured to show a right-eye image and a left-eye image alternately to a viewer using a liquid crystal in addition to a polarizer.

JP 2011-180266 A JP 2008-170557 A

  By the way, since the polarizing glasses have a fixed transmission axis, reflected light and scattered light in a specific direction are strongly removed, but these lights in different directions are not removed. Therefore, for example, if pilots use polarized glasses in the morning or evening, the scattered light in the sky is removed and the sky looks very dark, but if the airplane turns and tilts, the degree of polarization removal is There is a problem that it changes, looks brighter and the field of view changes greatly. Further, when a liquid crystal display is used for the instrument, there is a problem that the instrument cannot be seen depending on the direction of the polarization plane of light emitted from the liquid crystal display or the direction of the polarized glasses. Furthermore, if the reflected light from other aircraft is completely removed, there is a problem that the discovery of the airplane is delayed.

  Also, scattered light from fine particles such as smoke and water vapor can be removed by polarized glasses depending on the conditions, but in the case of polarized glasses, the light conditions and the direction of polarized glasses are the same as in the case of reflected light. There is a problem that the appearance changes depending on.

  In addition, a surgeon applies a strong light to look at the incision, but when viewing a surface wet with a liquid such as blood, if the reflected light is too strong, there is a problem that it is very difficult to see. On the other hand, if the reflected light is completely removed with polarized glasses, there is a problem that the shape of the surface is hardly captured. Similar problems occur when observing objects with similar surface reflections or when used in an environment with smoke or water vapor.

  In addition, polarized glasses or liquid crystal glasses that display different images on the left and right to view a three-dimensional image have a problem of giving the user a feeling of fatigue in order to view different images on the left and right.

  The present invention has been made in view of the background as described above, and provides polarized switching glasses that provide a good field of view and less fatigue in situations where there are various reflected light and scattered light. Objective.

This invention which solves an above-mentioned subject is polarization switching glasses provided with a right lens and a left lens, and a control device which controls the right lens and the left lens. The right lens includes a first liquid crystal cell that rotates linearly polarized light at a predetermined twist angle when no voltage is applied, and a first polarizer that is provided on the rear side in the traveling direction of light from the outside with respect to the first liquid crystal cell. Is provided. The left lens includes a second liquid crystal cell that rotates linearly polarized light at a predetermined twist angle when no voltage is applied, and a second polarizer that is provided behind the second liquid crystal cell in the traveling direction of light from the outside. Is provided.
The transmission axes of the first polarizer and the second polarizer are parallel, the twist angles of the first liquid crystal cell and the second liquid crystal cell are the same, and the control device includes the first liquid crystal cell. And a voltage having the same phase intermittently applied to the second liquid crystal cell at a predetermined frequency.

  Accordingly, the polarization switching glasses block a linearly polarized light component that crosses the transmission axes of the first polarizer and the second polarizer from light entering the first liquid crystal cell or the second liquid crystal cell from the outside. A state and a state in which a linearly polarized light component intersecting in a direction shifted by the twist angle with respect to the transmission axis are periodically switched. Therefore, it is possible to remove not only reflected light having a specific polarization plane but also reflected light having polarization planes of different orientations as in conventional polarizing glasses. For example, with conventional polarized glasses, only the reflected light from a horizontal surface such as the road surface and water surface could be removed, but the reflected light from the glass surface of the building could also be removed and used by the pilot Even in this case, a uniform polarization removal state can be obtained regardless of the attitude of the airplane and the attitude of the pilot. Even in the scattered light caused by fine particles such as smoke and water vapor, a uniform scattered light removal state can be obtained regardless of the posture of the user.

  Also, with this polarization switching glasses, the direction of the transmission axis of polarized light is periodically switched, so that only about half of the linearly polarized light of a specific polarization plane (depending on the duty ratio of voltage application) is removed, and everything is removed. Therefore, the reflected light (polarized light) having an appropriate intensity remains. Therefore, the display in the display can be visually recognized no matter how the polarization plane of light emitted from the liquid crystal display is set. Further, since all the reflected light is not removed, the reflected light from other aircraft can be visually recognized, and when observing a wet object, the shape can be accurately visually recognized while leaving moderate reflected light. In addition, scattered light caused by fine particles such as smoke and water vapor can be seen moderately, so that it is possible to suppress unnecessary approach even in the case of toxic fine particles.

Further, in the polarization switching glasses, the transmission axes of the first polarizer and the second polarizer are parallel, the twist angles of the first liquid crystal cell and the second liquid crystal cell are the same, and the control device includes the first liquid crystal cell. Since the same phase voltage is applied to the second liquid crystal cell, the user sees the same image in the left eye and the right eye. Therefore, it is hard to feel fatigue and can be used for a long time in driving a vehicle or in sports. Rather, since unpleasant reflected light and scattered light are appropriately removed, driving and play can be continued without feeling tired.
The transmission axis in the polarizer means a direction orthogonal to the absorption axis.

  In the polarization switching glasses described above, the twist angle may be 90 °.

  In the polarization switching glasses, the first liquid crystal cell and the second liquid crystal cell have a twist angle 2θ of less than 90 °, and the first polarizer and the second polarizer have a transmission axis in a vertical direction. It is desirable to incline at an angle θ of less than 45 °.

  According to such a configuration, since the polarization plane is mainly removed from the polarized light, a good field of view can be obtained in a normal situation where light enters from above. In this case, the twist angle 2θ is preferably 60 to 85 °, for example.

  In the polarization switching glasses described above, the polarizer may be composed of a guest / host type liquid crystal. At this time, the control device is configured to apply a voltage to the guest-host type liquid crystal.

  According to such a configuration, when a voltage is applied to the guest-host type liquid crystal, the guest-host type liquid crystal functions as a weak polarizer, and therefore, at a certain rate regardless of the direction of the polarization plane of linearly polarized light. Linearly polarized light can be removed. Apply to guest-host type liquid crystal

  In the polarization switching glasses described above, it is preferable that the control device is configured to be able to change at least one of a duty ratio for applying a voltage to the first liquid crystal cell and the second liquid crystal cell and the frequency.

  By comprising in this way, the visual field according to a user's liking can be obtained.

  In the polarization switching glasses described above, a duty ratio for applying a voltage to the transmission axis and the first liquid crystal cell and the second liquid crystal cell is set so as to remove more horizontal linear polarization than vertical linear polarization. It is desirable that

  According to such a configuration, since the polarization plane is removed centering on polarized light close to horizontal, a good field of view can be obtained in a normal situation where light enters from above.

  In the polarization switching glasses described above, the first liquid crystal cell and the second liquid crystal cell are configured as an integrated panel, and the first polarizer and the second polarizer are configured as an integrated polarizer. The lens and the left lens can be configured integrally.

  With this configuration, a wide field of view can be obtained.

  According to the polarized light switching glasses of the present invention, it is possible to provide a good field of view in a situation where there are various reflected light and scattered light, and to make the user feel less tired.

It is a perspective view of polarization switching glasses. It is a figure explaining the lens periphery of polarization switching glasses, (a) The figure which looked at the front frame from back, (b) The figure which looked at the back frame from back. It is a figure explaining the layer structure of a lens. It is a figure explaining the permeation | transmission state of light. It is a block diagram which shows the electric constitution of a control apparatus. It is a figure which shows the waveform of the control signal for applying a pulse voltage to a liquid crystal cell. It is a figure explaining the transmission state of a linearly polarized light, (a) In the case of a linearly polarized light with a horizontal polarization plane when no voltage is applied, and (b) A linearly polarized light with a horizontal polarization surface when a voltage is applied Show the case. It is a figure explaining the transmission state of a linearly polarized light, (a) In the case of a linearly polarized light with a vertical polarization plane when no voltage is applied, and (b) A linearly polarized light with a vertical polarization surface when a voltage is applied Show the case. It is a figure which shows the layer structure of the lens of the polarization switching spectacles concerning a 1st modification. It is a figure which shows the layer structure of the lens of the polarization switching spectacles concerning a 2nd modification. It is a figure explaining the twist angle of the (a) liquid crystal cell of the polarization switching glasses concerning the 3rd modification, and the transmission axis of (b) polarization. It is the figure of (a) liquid crystal cell of the polarization switching spectacles which concern on a 4th modification, (b) The figure of a polarizing plate. It is the figure which shows the layer structure of the (a) lens of the polarization switching spectacles concerning a 5th modification, (b) The figure which shows arrangement | positioning of an electrode.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the polarization switching glasses 1 according to an embodiment are configured to include a frame F for wearing on the head, a right lens 50R and a left lens 50L, and a control device 30. In the following description, front / rear, left / right, and upper / lower follow the front / rear, left / right, and upper / lower of the person wearing the polarization switching glasses 1.

  The frame F includes a frame body 10 that holds the right lens 50R and the left lens 50L, a left vine 20L, and a right vine 20R. The frame body 10 includes a rim 11L that holds the left lens 50L, a rim 11R that holds the right lens 50R, and a bridge 12 that connects the left rim 11L and the right rim 11R. In the frame F of the present embodiment, the rims 11L and 11R and the bridge 12 are integrally formed of resin. More specifically, as shown in FIGS. 2A and 2B, the frame body 10 includes a front frame 10F and a rear frame 10R, and the rear frame 10R is fastened to the front frame 10F with a small screw (not shown). Thus, the right lens 50R and the left lens 50L are held between the front frame 10F and the rear frame 10R. The pad 13 is attached to the rear frame 10R. Between the front frame 10F and the rear frame 10R, a space for storing a wiring cord (not shown) is formed.

  As shown in FIG. 1, the left vine 20 </ b> L is provided with a box-shaped substrate storage portion 31 in which a control substrate 31 </ b> A is stored in a portion facing the temple when worn by a person. An opening 15 </ b> P is formed in the board storage part 31 on the outer side in the left-right direction so that the display part 38 connected to the internal control board 31 </ b> A can be seen. Switches 35B to 35E serving as operation units connected to the control board 31A are exposed to the substrate storage unit 31 so as to be exposed to the outside.

  The right vine 20 </ b> R is provided with a box-shaped battery part 32 in which a battery 32 </ b> A is housed at a position symmetrical to the board housing part 31. The battery unit 32 is provided with a main switch 35A that switches on / off the power supply of the control board 31A so as to protrude downward.

  Both the right lens 50R and the left lens 50L have the same layer configuration. As shown in FIG. 3, the liquid crystal cell 110 as an example of the first liquid crystal cell and the second liquid crystal cell, the first polarizer, and the first lens The polarizing plate 120 is an example of a two-polarizer. In FIG. 3, the upper side of the figure is the external side of the lens, and the lower side is the wearer side.

The liquid crystal cell 110 has two transparent substrates 110A and 110B, and a transparent electrode made of an ITO (indium tin oxide) film (not shown) is provided on the opposing surfaces of the transparent substrates 110A and 110B. On the transparent electrode (inside the liquid crystal cell 110), alignment films 105A and 105B that are rubbed in a predetermined direction are provided. The direction of each rubbing treatment of the alignment films 105 </ b> A and 105 </ b> B is shifted by 90 ° around the normal line of the liquid crystal cell 110. As is well known, liquid crystal is sealed between the alignment films 105A and 105B. Light passing through the liquid crystal cell 110 has a predetermined twist angle when no voltage is applied between the transparent electrodes. As seen from the traveling direction of light, it is configured to rotate leftward at a twist angle of 90 °.
On the other hand, when a voltage is applied between the transparent electrodes by the control device 30, since the major axis of the liquid crystal is aligned with the opposing direction of the transparent electrode and the polarization direction of the light is not rotated, the light from the outside does not change the polarization direction as it is. It has come to pass.

The polarizing plate 120 is provided behind the liquid crystal cell 110 in the traveling direction of light from the outside, and is attached to the liquid crystal cell 110. In FIG. 3, a bidirectional arrow shown on the polarizing plate 120 indicates the direction of the transmission axis of polarized light. As an example, the transmission axis is parallel to the rubbing direction of the alignment film 105B of the transparent substrate 110B to which the polarizing plate 120 is attached, but may be orthogonal.
As is known, the polarizing plate 120 blocks a linearly polarized light component orthogonal to the transmission axis.
As shown in FIG. 4, in both the right lens 50R and the left lens 50L, the transmission axis of the polarizing plate 120 is parallel to each other in the horizontal direction.

  With such a configuration, the right lens 50R and the left lens 50L rotate the polarization direction of light from the outside (refer to the arrow for the traveling direction) 90 ° to the left by the liquid crystal cell 110 when no voltage is applied, and the liquid crystal cell 110 Of the light that has passed through, only the horizontal linearly polarized light component passes through the polarizing plate 120. In FIG. 4 and the like, for the sake of understanding of the invention, the liquid crystal cell 110 and the polarizing plate 120 are shown apart for convenience, but in actuality they are in close contact.

As shown in FIG. 5, the control device 30 is a device that periodically switches and controls the direction of the transmission axis of linearly polarized light by applying a pulse voltage to the liquid crystal cells 110 of the right lens 50R and the left lens 50L. 32A and a control board 31A connected to the battery 32A via a main switch 35A.
The control board 31A includes a pulse generator 36a, a frequency control device 36b, a pulse width control device 36c, a setting selection unit 36d, a liquid crystal cell driver 36e, an LCD driver 36f, and a setting storage unit 39.

  The setting storage unit 39 stores a duty ratio of a pulse (a time ratio for applying a voltage to the liquid crystal cell 110 of the right lens 50R and the left lens 50L), a frequency, and the like.

  The setting selection unit 36d is connected to a sleep switch 35B, a down switch 35D, an up switch 35C, and a mode switch 35E. The mode switch 35E is a switch that is switched every time the duty change mode for changing the duty ratio and the frequency change mode for changing the frequency are pressed. In the duty change mode, the duty ratio can be changed within a range of 1 to 99% by operating the down switch 35D and the up switch 35C. Further, when the mode switch 35E is pressed to enter the frequency change mode, the frequency of the pulse signal can be set in the range of 1 to 500 Hz, for example, by operating the down switch 35D and the up switch 35C. The setting storage unit 39 stores the currently selected setting when the sleep switch 35B is pressed during operation.

  The duty ratio read from the setting storage unit 39 is output to the pulse width control device 36c, and the frequency is output to the frequency control device 36b. The frequency of the pulse signal generated by the pulse generator 36a is changed by the operation of the frequency control device 36b. The pulse signal generated by the pulse generator 36a is output to the pulse width control device 36c, and the pulse width is changed by the pulse width control device 36c before being output to the liquid crystal cell driver 36e.

  The liquid crystal cell driver 36e amplifies the pulse signal input from the pulse width control device 36c to the operating voltage of the liquid crystal cell 110 and outputs it to them. The output terminal of the liquid crystal cell driver 36e is connected in parallel to the respective liquid crystal cells 110 of the right lens 50R and the left lens 50L. Note that the polarity of the voltage applied from the liquid crystal cell driver 36e to the liquid crystal cell 110 is alternately switched as is well known. This polarity switching is performed at an appropriate frequency that does not depend on the frequency of the pulse.

  The setting information read by the setting selection unit 36d is output to the LCD driver 36f and displayed on the display unit 38 by the LCD driver 36f. As described above, when the sleep switch 35B is pressed during the operation of the polarization switching glasses 1, the setting selection unit 36d stores the current setting in the setting storage unit 39, and the pulse generator 36a, the frequency control device 36b, The operations of the pulse width controller 36c, the setting selector 36d, the liquid crystal cell driver 36e, and the LCD driver 36f are stopped. When the sleep switch 35B is pressed again during the stop state, the stored current setting is read and the operation is started again with the setting before the stop. When the power is turned off by the main switch 35A, the setting storage unit 39 resets the changed setting value, and when the power is turned on next time, the preset duty ratio and frequency are read out. The preset duty ratio is, for example, 50%, and the frequency is 50 Hz or more, for example, 60 Hz.

The operation of the polarization switching glasses 1 configured as described above will be described.
The user wears the polarization switching glasses 1 on the head in the same manner as normal glasses, and presses the main switch 35A to turn on the control board 31A. The control board 31A reads the duty ratio and frequency as preset initial values from the setting storage unit 39, and outputs them to the frequency control device 36b and the pulse width control device 36c. The frequency controller 36b changes the frequency of the pulse signal generated by the pulse generator 36a, and the pulse generator 36a generates a pulse signal according to this frequency and outputs it to the pulse width controller 36c. The pulse width control device 36c outputs a pulse signal whose pulse width has been changed to the liquid crystal cell driver 36e. The liquid crystal cell driver 36 e converts the input pulse signal into a voltage suitable for the operation of the liquid crystal cell 110 and outputs the voltage to the liquid crystal cell 110. In addition, the LCD driver 36f displays the setting name on the display unit 38.

  Accordingly, a pulse voltage is applied to the liquid crystal cell 110 at a selected frequency and a predetermined peak voltage in accordance with the control signal shown in FIG. FIG. 6 shows a signal when the duty ratio is 50% as an example, but when the duty ratio is larger than 50%, the time of the peak voltage V1 is long, and conversely, when the duty ratio is larger than 50%. The pulse width is changed so that the time of the peak voltage V1 is shortened. The voltage corresponding to the pulse signal in the form of FIG. 6 is applied to the liquid crystal cells 110 of the right lens 50R and the left lens 50L in the same phase.

The light transmission state of the right lens 50R and the left lens 50L according to the state of light from the outside and the state of voltage application to the liquid crystal cell 110 will be described with reference to FIGS.
As shown in FIG. 7A, when linearly polarized light having a horizontal polarization plane from the outside enters the right lens 50R and the left lens 50L when no voltage is applied to the liquid crystal cell 110, the linearly polarized light is converted into the liquid crystal cell. 110 is rotated 90 ° to the left and becomes linearly polarized light having a vertical polarization plane. Therefore, it cannot pass through the polarizing plate 120 having a horizontal transmission axis.
On the other hand, as shown in FIG. 7B, when a linearly polarized light having a horizontal polarization plane from the outside enters the right lens 50R and the left lens 50L when a voltage is applied to the liquid crystal cell 110, the linearly polarized light is The liquid crystal cell 110 passes through without being rotated. Therefore, it can pass through the polarizing plate 120 having a horizontal transmission axis.

As shown in FIG. 8A, when linearly polarized light having a polarization plane in the vertical direction from the outside enters the right lens 50R and the left lens 50L when no voltage is applied to the liquid crystal cell 110, the linearly polarized light is converted into the liquid crystal cell. 110 is rotated 90 ° to the left to become linearly polarized light having a horizontal polarization plane. Therefore, it can pass through the polarizing plate 120 having a horizontal transmission axis.
On the other hand, as shown in FIG. 8B, when linearly polarized light having a polarization plane in the vertical direction from the outside enters the right lens 50R and the left lens 50L when a voltage is applied to the liquid crystal cell 110, the linearly polarized light is The liquid crystal cell 110 passes through without being rotated. Therefore, it cannot pass through the polarizing plate 120 having a horizontal transmission axis.

  Therefore, for example, when a pulse voltage having a frequency of 60 Hz and a duty ratio of 50% is applied to the liquid crystal cell 110, about 50% of linearly polarized light having a horizontal polarization plane is removed, and linearly polarized light having a vertical polarization plane is also removed. Approximately 50% is removed (actually less than 50% due to the transmittance of the polarizer). Further, linearly polarized light having an oblique polarization plane is also removed by about 50% in total because the vertical component and horizontal component are each removed by 50%. For this reason, the polarization switching glasses 1 of this embodiment can remove about 50% of unpleasant reflected light regardless of the orientation of the polarization plane.

  When the user wants to preferentially remove linearly polarized light having a horizontal polarization plane, the state shown in FIG. 7A, that is, the voltage non-application time may be increased. Good. Conversely, if the user wants to remove linearly polarized light with a vertical polarization plane preferentially, the state shown in FIG. 8B, that is, the voltage application time can be lengthened. Make it bigger.

  The frequency of the pulse voltage should be 50 Hz or more, more preferably 60 Hz or more in normal use, and thereby flicker can be eliminated, and there is no problem even if the frequency is high such as 100 Hz or 200 Hz. . When it is desired to inspect the rotation state, phase, etc. of the rotating object using the change in the transmission state of polarized light, the frequency may be set according to the rotation speed of the rotating object. In such a case, the frequency is smaller than 50 Hz. It is good also as a frequency.

  In this way, according to the polarization switching glasses 1 of the present embodiment, linearly polarized light entering from the outside can be removed at a rate corresponding to the duty ratio regardless of the direction of the polarization plane. For example, with conventional polarized glasses, only the reflected light from a horizontal surface such as the road surface and water surface could be removed, but the reflected light from the glass surface of the building could also be removed and used by the pilot Even in this case, a uniform polarization removal state can be obtained regardless of the attitude of the airplane and the attitude of the pilot. Even in the scattered light caused by fine particles such as smoke and water vapor, the scattered light can be uniformly removed regardless of the posture of the user.

  In addition, since the polarization switching glasses 1 periodically switch the direction of the transmission axis of polarized light, the polarized light of the specific polarization plane is only removed at a rate corresponding to the duty ratio, and not all are removed. Intense reflected light (polarized light) remains. Therefore, it can be visually recognized no matter how the polarization plane of light emitted from the liquid crystal display is set. Further, since all the reflected light is not removed, the reflected light from other aircraft can be visually recognized, and when observing a wet object, the shape can be accurately visually recognized while leaving moderate reflected light. In addition, scattered light caused by fine particles such as smoke and water vapor can be seen moderately, so that it is possible to suppress unnecessary approach even in the case of toxic fine particles.

  Further, in the polarization switching glasses 1, the polarization transmission axes of the right lens 50R and the left lens 50L are parallel, the twist angles of the left and right liquid crystal cells 110 are the same, and the control device 30 is the same as the left and right liquid crystal cells 110. Since the phase voltage is applied, the user sees the same image with the left eye and the right eye. For this reason, the user is less likely to feel fatigue and can use it for a long time in driving a vehicle or in sports. Rather, since unpleasant reflected light and scattered light are appropriately removed, driving and play can be continued without feeling tired.

  Moreover, since the polarization switching glasses 1 can change the duty ratio and frequency of the voltage applied to the liquid crystal cell 110, it is possible to obtain a field of view according to the user's preference.

Although an example of the polarization switching glasses of the present invention has been described above, the polarization switching glasses are not limited to the above-described form, and can be appropriately modified and implemented.
For example, in the above embodiment, both the duty ratio and the frequency of the voltage applied to the liquid crystal cell 110 are configured to be changeable. However, only one of the duty ratio and the frequency may be configured to be changed. A configuration that cannot be changed is also possible.

  In the above embodiment, the duty ratio (preset value) at startup is set so as to remove the linearly polarized light in the vertical direction and the linearly polarized light in the horizontal direction at the same ratio. The transmission axis of the polarizing plate 120 and the duty ratio of the voltage applied to the liquid crystal cell 110 may be set so as to remove a large amount of linearly polarized light in the horizontal direction. For example, in the embodiment, the duty ratio at the time of activation may be smaller than 50%. According to such a configuration, since the polarization plane is mainly removed from the linearly polarized light, a good field of view can be obtained in a normal situation where light enters from above. The same applies even if the transmission axis of the polarizing plate 120 is horizontal and the duty ratio of the voltage applied to the liquid crystal cell 110 is greater than 50%.

  Further, as shown in FIG. 9, the liquid crystal cell 150 and the polarizing plate 160 may be arranged in this order on the rear side of the polarizing plate 120. The liquid crystal cell 150 includes a transparent substrate 150A and a transparent substrate 150B, and has the same configuration as the liquid crystal cell 110. The polarizing plate 160 has a transmission axis oriented in a direction perpendicular to the transmission axis of the polarizing plate 120. The control device 30 applies a voltage to the liquid crystal cell 150 simultaneously with applying a voltage to the liquid crystal cell 110. This voltage is a continuous DC voltage (the polarities are alternately switched). Moreover, the control apparatus 30 is comprised so that the voltage applied to the liquid crystal cell 150 can be adjusted by the user (it can adjust also in the state which does not apply a voltage).

According to such a configuration, in the embodiment described with reference to FIGS. 7 and 8, in a state where some linearly polarized light in FIG. 7B and FIG. A predetermined proportion of the linearly polarized light transmitted through the polarizing plate 120 can be removed by the polarizing plate 160. Further, the ratio of the removal rate of linearly polarized light in the vertical direction and the removal rate of linearly polarized light in the horizontal direction can be changed according to the magnitude of the voltage applied to the liquid crystal cell 150.
That is, the transmittance (brightness for the user) can be adjusted by the liquid crystal cell 150 and the polarizing plate 160 added in this modification, and the removal rate for each direction of the polarization plane of linearly polarized light can be adjusted. Can do.
Note that the direction of the transmission axis of the polarizing plate 160 may be parallel to the polarizing plate 120.

  Further, as shown in FIG. 10, in the right lens 50R and the left lens 50L, as shown in FIG. 10, a polarizer is used to reduce or adjust the proportion of linearly polarized light to be removed. A liquid crystal cell 220 made of guest-host type liquid crystal can be obtained. At this time, the control device 30 is configured to apply a voltage to the liquid crystal cell 220. Similarly to the liquid crystal cell 110, the liquid crystal cell 220 includes transparent substrates 210A and 210B provided with alignment films, and transparent electrodes 205A and 205B are provided on the opposing surfaces of the transparent substrates 210A and 210B. Yes.

  The control device 30 applies a voltage to the liquid crystal cell 220 simultaneously with applying a voltage to the liquid crystal cell 110. The voltage applied to the liquid crystal cell 220 is a continuous DC voltage (the polarities are alternately switched). The magnitude of this voltage is preferably adjustable by the user.

There are two types of guest-host type liquid crystal: positive type guest host and negative type guest host. N-type nematic liquid crystal is used and vertically aligned is called positive type guest host. P type nematic liquid crystal The one that is used and subjected to the horizontal alignment treatment is called a negative type guest host.
The guest / host type liquid crystal used here is a positive type guest host, and when no voltage is applied, the dichroic dye corresponding to the guest of the guest / host is aligned in the direction perpendicular to the substrate, and light is hardly absorbed. On the other hand, when a voltage is applied, light is absorbed and the transmittance decreases.

Therefore, when no voltage is applied to the polarization switching glasses according to the modified example, the state is similar to the state without the polarizing plate, and the user can see the outside world in a bright state.
When the polarization switching glasses are operated, the guest / host type liquid crystal absorbs light. This absorptivity (that is, light transmittance) can be adjusted by a voltage applied to the liquid crystal cell 220. At the same time, the guest-host liquid crystal can function as a weak polarizer due to fluctuations in linearly polarized light caused by fluctuations in the liquid crystal. The strength of the polarizer can also be adjusted by the magnitude of the voltage applied to the guest / host type liquid crystal.

  For this reason, in the polarization switching glasses according to the modification, linearly polarized light can be removed at a certain rate regardless of the direction of the polarization plane of the linearly polarized light, as in the above-described embodiment. Then, the light absorptivity and the linearly polarized light removal ratio can be adjusted.

  In the polarization switching glasses of the present invention, as shown in FIG. 11, the first liquid crystal cell and the second liquid crystal cell (liquid crystal cell 110) have a twist angle 2θ of less than 90 °. The polarizer may be configured such that the transmission axis is inclined at an angle θ of less than 45 ° with respect to the vertical direction. In this case, the twist angle 2θ is preferably 60 to 85 °, for example. At this time, the transmission axis of the polarizer is preferably in a direction parallel or orthogonal to the rubbing direction of the alignment film.

  According to such a configuration, when no voltage is applied to the liquid crystal cell 110, the linearly polarized light from the outside rotates by 2θ around the optical axis, and thereafter, a component orthogonal to the transmission axis in FIG. Is cut off. For this reason, the linearly polarized light component in the vibration direction orthogonal to the straight line L1 in FIG. On the other hand, when a voltage is applied to the liquid crystal cell 110, the linearly polarized light from the outside passes through the liquid crystal cell 110 as it is, so that the linearly polarized light component orthogonal to the transmission axis in FIG. That is, since a large amount of linearly polarized light components that are relatively close to the horizontal direction are blocked, a good field of view can be obtained in a normal situation where light enters from above.

In addition, as shown in FIG. 12A, the polarization-switching glasses of the present invention are configured by integrating the first liquid crystal cell and the second liquid crystal cell as an integrated panel, and as shown in FIG. By configuring the polarizer and the second polarizer as an integrated polarizing plate (polarizer) 320, the right lens and the left lens may be configured integrally.
With this configuration, a wide field of view can be obtained.
Note that the liquid crystal cell in FIG. 12A has a twist angle of 90 ° to the left, and the polarizing plate 320 in FIG. 12B has a transmission axis in the vertical direction as an example.

  Further, as shown in FIG. 13A, an IPS (In-Place-Switching) liquid crystal cell 410 may be used as the liquid crystal cell so that the appearance is not easily changed depending on the angle of light incident on the lens. The IPS liquid crystal cell 410 includes two transparent substrates 410A and 410B, and alignment films 405A and 405B that are rubbed in a predetermined direction are provided on the opposing surfaces of the transparent substrates 410A and 410B. The direction of each rubbing treatment of the alignment films 405A and 405B is shifted by 90 ° around the normal line of the IPS liquid crystal cell 410. As shown in FIG. 13B, the transparent substrate 410B has a first transparent electrode 430A formed in a comb-teeth shape and a second tooth formed in a comb-teeth shape so as to enter between the first transparent electrodes 430A. A transparent electrode 430B is provided.

  As is well known, liquid crystal is sealed between the alignment films 405A and 405B, and light passing through the IPS liquid crystal cell 410 has a predetermined twist angle when no voltage is applied between the transparent electrodes, here as an example. It is rotated at a twist angle of 90 ° to the left with respect to the traveling direction of light. On the other hand, when a voltage is applied between the first transparent electrode 430A and the second transparent electrode 430B, the major axis of the liquid crystal is aligned so as to follow the direction of the electric field, and passes through without rotating the polarization direction of light from the outside. Let Therefore, the basic action is the same as that of the polarization switching glasses 1 of the above embodiment, but when applying a voltage, since the major axis of the liquid crystal is parallel to the lens surface and does not become oblique, light from the outside world is There is little change in appearance when entering the surface diagonally, and a better field of view can be obtained.

DESCRIPTION OF SYMBOLS 1 Polarization switching glasses 10 Frame main body 30 Controller 50L Left lens 50R Right lens 105A Alignment film 105B Alignment film 110 Liquid crystal cell 110A Transparent substrate 110B Transparent substrate 120 Polarizing plate

Claims (8)

Polarized switching glasses comprising a right lens and a left lens, and a control device for controlling the right lens and the left lens,
The right lens includes a first liquid crystal cell that rotates linearly polarized light at a predetermined twist angle when no voltage is applied, and a first polarizer that is provided on the rear side in the traveling direction of light from the outside with respect to the first liquid crystal cell. With
The left lens includes a second liquid crystal cell that rotates linearly polarized light at a predetermined twist angle when no voltage is applied, and a second polarizer that is provided behind the second liquid crystal cell in the traveling direction of light from the outside. With
The transmission axes of the first polarizer and the second polarizer are parallel,
The twist angles of the first liquid crystal cell and the second liquid crystal cell are the same,
The control device is configured to intermittently apply the same phase voltage at a predetermined frequency to the first liquid crystal cell and the second liquid crystal cell,
Of light entering the first liquid crystal cell or the second liquid crystal cell from the outside, a state where a linearly polarized component intersecting a transmission axis of the first polarizer and the second polarizer is blocked, and with respect to the transmission axis The polarized light switching glasses, wherein the polarized light switching glasses are configured to periodically switch between a state in which linearly polarized light components intersecting in a direction shifted by the twist angle are blocked.   The polarized light switching glasses according to claim 1, wherein the twist angle is 90 °. The first liquid crystal cell and the second liquid crystal cell have a twist angle 2θ of less than 90 °,
2. The polarization switching glasses according to claim 1, wherein the first polarizer and the second polarizer are inclined at an angle θ of less than 45 ° with respect to a vertical direction.   The polarization switching glasses according to claim 3, wherein the twist angle 2θ is 60 to 85 °. The polarizer comprises a guest-host type liquid crystal,
The polarized light switching glasses according to any one of claims 1 to 4, wherein the control device is configured to apply a voltage to the guest-host type liquid crystal.   6. The control device according to claim 1, wherein the control device is configured to change at least one of a duty ratio for applying a voltage to the first liquid crystal cell and the second liquid crystal cell and the frequency. The polarized light switching glasses according to claim 1.   The transmission axis and a duty ratio for applying a voltage to the first liquid crystal cell and the second liquid crystal cell are set so as to remove more horizontal linear polarization than vertical linear polarization. The polarized light switching glasses according to any one of claims 1 to 6.   The first liquid crystal cell and the second liquid crystal cell are configured as an integral panel, and the first polarizer and the second polarizer are configured as an integral polarizer, so that the right lens and the left lens are The polarized light switching glasses according to any one of claims 1 to 7, wherein the polarized light switching glasses are integrally formed.

Images