JPH0250123A - Electronic sunglasses - Google Patents

Abstract

PURPOSE:To realize the electronic sunglasses which are used practically by specifying the twist angle of liquid crystal panels as an orienting direction and aligning the orienting direction with the axes of absorption or polarization of a couple of polarizing plates, specifying the angle to the axis of polarization of the object-side polarizing plate of a left or right eye liquid crystal panel, and using a solar battery as a power source. CONSTITUTION:The twist angle of the liquid crystal panels 1 which are made of synthetic resin as their base materials and employ a twist nematic system has an orienting direction of 60-80 deg. to 100-120 deg., and the orienting direction is aligned with the axes E and D of absorption or polarization of the couple of polarizing plates. Then a smaller angle between the angles to the axes of polarization of the object-side polarizing plates of the left and right eye liquid crystal panels is set to <45 deg. and the solar battery 2 is used as the power source for driving the liquid crystal panel 1. Consequently, the value of minimum transmissivity can be adjusted and the variation width of the transmissivity is freely set, so the electronic sunglasses which are free from a feeling of physical disorder are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to electronic sunglasses that control light transmittance by utilizing the electro-optic effect of a liquid crystal material.

[Conventional technology 1] Sunglasses with variable transmittance have been widely used in the past by utilizing the property of otochromic substances to be colored by light, by dispersing photochromic substances in the lenses, or by dispersing photochromic substances on the surface of the lenses. These were sunglasses made with a photochromic thin film.

However, sunglasses made with photochromic substances take a long time to react to and become colored after being exposed to light (for example, when you are driving at night and are hit by the headlights of an oncoming car). However, the photochromic material deteriorates over time, and the coloring does not disappear even in a dark place.

In order to overcome these drawbacks of photochromic sunglasses and provide sunglasses with a quick response, many electronic sunglasses that utilize the electro-optic effect of liquid crystal materials have been proposed. Such electronic sunglasses have attracted attention as display devices that can be made thin with low power consumption, and are based on the principles of liquid crystal display devices that are currently widely used.The principles are as follows.

Then, 2 temporary IA nematic liquid crystals with transparent electrodes formed on the inner 1+1 surfaces are sealed, and the substrate surfaces are subjected to alignment treatment, so that the liquid crystal molecules are separated from the part in contact with one substrate and the part in contact with the other substrate. The portions in contact with the substrate are oriented so as to be perpendicular to each other. As a result, the liquid crystal molecules in the middle twist in a spiral, allowing the incident light to shine through a 90-degree angle. A polarizing plate is provided on the outside of each of the two substrates, and the polarization axis is parallel to the orientation direction of the substrate that is in contact with each other (i.e.,
When the polarization axes of the two polarizing plates are perpendicular to each other), in that state, the incoming light of Q1 is transmitted. On the other hand, when a voltage is applied to liquid crystal molecules, the liquid crystal molecules align in a direction parallel to the direction of the voltage (that is, a direction perpendicular to the two substrates).
The spiral state is eliminated and the incident light passes through the liquid crystal molecules without being rotated. However, since the polarization axes of the two polarizing plates are perpendicular to each other, the incident light that has passed through the 1(U product molecule) is blocked by the polarized light beam on the output side.

Conversely, if the polarization axes of the two polarizing plates are made parallel,
When no voltage is applied, the incident light shines 90 degrees,
Since it is perpendicular to the polarization axis of the polarizing plate on the output side, it is blocked, and when a voltage is applied, the incident light is not rotated and can be transmitted.

In either of the above methods, it is possible to control whether light is transmitted or blocked depending on whether or not a voltage is applied.

This principle is called the twisted nematic method,
Most of the liquid crystal display devices that are currently widely used are based on this principle, and many of the electronic sunglasses that have been proposed so far are also based on this principle. Conventional electronic glasses are equipped with a twisted nematic panel (corresponding to a conventional lens), which detects the brightness of the surrounding area and adjusts the LCD panel according to the amount of light. This section controls the application or non-application of voltage to the terminal and controls the amount of light transmitted.
: Uses solar cells as a source, and when the surroundings are bright :゛su,
That is, electronic sunglasses have also been proposed in which voltage is applied to the liquid crystal panel only when an electromotive force is generated in the solar cell.

(Problem to be solved by the invention 1) In this way, electronic sunglasses using a liquid crystal panel have 1
Although many proposals have been made since then, they have not yet been put into practical use due to the following drawbacks.

-V However, in the past, a tunorasu substrate was generally used as a substrate for a liquid crystal panel. This is due to strength issues and, in the case of liquid crystal display devices, in order to make the display contrast uniform, it is necessary to make the gap between the two substrates in which the liquid crystal is sealed, so-called cell gap, uniform.

However, liquid crystal panels using such glass substrates are too heavy to use in electronic sunglasses, and additional circuits and power supplies are required to drive the liquid crystal panels, which increases the weight of the glasses as a whole and reduces the comfort of wearing them. It has the disadvantage that it worsens the condition and cannot withstand continuous wear for long periods of time. A more serious problem is that the glass substrate is easily damaged, so there is a high risk of damage due to impact, resulting in fatal damage to the eyeballs and face, which is a safety issue.

Furthermore, in the twisted nematic method, when the light is blocked, the incident light is almost completely blocked.

In the case of a display device, this is preferable because it improves the display contrast, but in the case of sunglasses, if the visibility becomes zero, it cannot be used, especially when driving a car. This poses a serious risk of causing a serious accident and is a serious matter.

Furthermore, it is well known that twisted nematic liquid crystal panels have viewing angle dependence, that is, the light transmittance changes depending on the viewing angle. In the case of a display device, it is not a big problem if it is installed relatively far away and viewed at a nearly constant angle, but in the case of electronic sunglasses, the liquid crystal panel is located extremely close to the eyeballs. Furthermore, because the eyeballs move when viewing the surroundings, the angle between the line of sight and the liquid crystal panel changes significantly. As a result, the transmittance changes depending on the direction of the line of sight, which is perceived by the user as a change in a-tone or unevenness, which significantly worsens the feeling of wearing, making it impractical for practical use.

Furthermore, a problem unique to electronic sunglasses is that it is necessary to manufacture one product panel separately for the right eye and the left eye, and attach it to the frame separately. If the direction is misaligned, the amount of light transmitted on the left and right sides will be different, resulting in a problem of significantly worsening the wearing comfort.

This problem will be solved if the left and right polarization axes are manufactured in the same direction, but it may be possible to manufacture them in a way that perfectly matches them if they are made by hand by highly skilled workers, but it is not possible with mass production. This is not possible if you are trying to manufacture it cheaply.

As mentioned above, electronic sunglasses using liquid crystal panels are
Although many engineers have proposed and researched this technology since ancient times, it has been difficult to put it into practical use due to various factors.

An object of the present invention is to provide electronic sunglasses that can be put to practical use by solving various problems that have made it difficult to put them into practical use.

[Means for Solving the Problems] The electronic sunglasses of the present invention improve the electro-optic effect of liquid crystals by II.
In the electronic sunglasses used in I, a) the base material of the liquid crystal panel constituting the variable transmittance section is made of synthetic resin, b) the liquid crystal panel is constructed by the twisted nematic method, and C) the twist of the liquid crystal panel using the twisted nematic method is used. r
Strike angle is 60° or more and 80° or less, or 100° 1 above 1
having an alignment direction of 20° or less, and matching the absorption axis or polarization axis of the pair of polarizing plates with the alignment direction; d) the polarization axis of the objective side polarizing plate of the liquid crystal panel for six eyes and the left eye;
The smaller of the angles formed by the polarizing plate on the objective side of the liquid crystal panel (with respect to the polarization axis) is less than 45'', and a solar cell is used as a power source to drive the liquid crystal panel.
Atsushi.

Further, the solar cell is characterized in that the light-receiving area S is within the range expressed by the following formula.

S≦24crn' [Function 1] The weight in B fi2 has an important meaning not only in sunglasses but also in actual use. That is, the more the weight increases, the worse the wearing feeling of the glasses becomes, and the more difficult it becomes to wear them for a long time. A desirable weight for eyeglasses is 50 g or less, and when a synthetic resin base material is used for the lens of ordinary eyeglasses, the weight is about 30 g1iii. Electronic sunglasses differ from regular glasses in that they require a liquid crystal panel, power supply, and drive.
Since it is composed of a control circuit section, a mounting section thereof, and many other parts, it is desirable to limit the weight of each part as much as possible.

In the present invention, as a method for reducing the weight of electronic sunglasses,
We conducted extensive research on liquid crystal panels and solar cells, which are considered to be the most effective components for weight reduction.

Regarding the liquid crystal panel, the following results were obtained. When a synthetic resin base material and a glass base material are used as the base material of a liquid crystal panel, the glass base material is approximately twice as heavy for the same shape and thickness.1-11.

When we actually made a prototype liquid crystal panel with the lens shape of sunglasses and measured its weight, the lens part, which is the transmittance variable part, had a thickness of 2 mm and Mi 26 cm', and the glass base material weighed 16.2 g. Synthetic solid fat base material 0:00, 79g
It became. From this, it is possible to reduce the weight of both eyes by approximately 16 g simply by changing the base material of the liquid crystal panel used in actual electronic sunglasses from glass to synthetic resin.

Since the liquid crystal panel is used as the transmittance variable part, that is, the lens part, of electronic sunglasses, it is necessary to consider not only the weight but also safety. If the base material of the liquid crystal panel is glass, it is very dangerous if it breaks, so in order to ensure safety, the thickness of the variable transmittance part must be set thicker than that of synthetic resin. This also becomes a negative factor in terms of weight.

Various methods can be used to use a synthetic resin base material as a base material for a liquid crystal panel. For example, a transparent electrode film such as an ITO film is directly provided on a synthetic resin base material, and after alignment treatment is performed. , a method in which liquid crystal is sealed between synthetic resin base materials fixed with spacers, and a polarizing plate is bonded to form a liquid crystal panel, and a film-like liquid crystal panel in which the base material is made of synthetic 134 resin film is used. If a film-like liquid crystal panel is suitable for strength, a separately formed composite material (oil base material) is attached to one or both sides of the film-like liquid crystal panel with a transparent adhesive to form a liquid crystal panel. There are methods to make the transmittance variable part, but it is sufficient that most of the transmittance variable part is made of synthetic resin.6 The shape of the base material may be a flat plate or a slope with curvature. If it is desired to serve as a lens, it is also possible to use a lens-shaped base material having a curvature that matches the power of 1 degree.

Regarding solar cells, the weight can be reduced by defining the light-receiving area of the solar cell. The lower limit of the light-receiving area is determined by the performance of the solar cells and the power required to drive the liquid crystal panel, but the upper limit is limited by heavy engineering.

When defining the light-receiving area of a solar cell, the weight balance with the pond components is a condition, so the weight 1 of the other components was investigated.

The frame of the sunglasses consists of a frame that supports the transmittance variable part and a temple part that is used as an ear hook, and both the cell frame and the metal frame are light, weighing about 17g.

The weight of the transmittance variable part depends on its area and thickness, but the area for normal sunglasses is 26 Cm' 1ii7rF.
Since it does not change with i, it mainly depends on the thickness. When a component panel is made of synthetic resin, it is easily deformed by external force, so a thickness of at least 2 mm is required. This was discovered through investigation by applying various external forces to the liquid crystal panel. Therefore, as mentioned above, the weight of the liquid crystal panel serving as the variable transmittance section is about 8 g for one eye, and about 16 g for both eyes.

The total weight of the frame and variable transmittance part is about 33g, but to obtain sunglasses that are comfortable to wear, the total weight is 50g.
It is desirable that the total weight of the remaining parts, the solar cell, the circuit, and the mounting part of the solar cell and the circuit is 5.
The condition is that it is 0g - 33g = 17g or less.

It is possible to reduce the weight of the circuit part to less than 1g using integration technology, so the weight of the solar cell and circuit mounting part can be reduced to 1g or less.
It is necessary to keep the weight under 6g.

As the light-receiving area of a solar cell increases, its mounting area also increases. Even if the mounting part is made of a lightweight synthetic resin, if the mounting part is required to have a strength that can withstand λ for practical use, measurements have shown that the ff1ffi of the mounting part and the solar cell will be approximately the same weight. In other words, if the weight of the solar cell is 8 g or less, electronic sunglasses that are comfortable to wear can be obtained.

A solar cell made of amorphous silicon formed on a glass substrate, which is inexpensive and widely used, weighs a relatively thick 1 m
Since it is about 0.3g per 1cm' in a m-1.2mm storage, the light-receiving area of the solar cell is about 24cr.
It is desirable that it be n' or less.

Of course, the weight values mentioned above will vary depending on the material and size of each part, but the average value is 24
cm' was determined. Furthermore, in terms of design, a value larger than this is not preferable because the area of the solar cell becomes too large.

Furthermore, in the present invention, the viewing angle dependence of the twisted nematic 1F panel, the variable transmittance, and the 1iR1
By improving the lower limit, we created a liquid crystal panel that can withstand practical use as electronic sunglasses.

Improvements were made mainly in the following two areas.

Regarding the twist angle in the twisted nematic method and the scissor angle of the polarizing plate.

2 Refractive index anisotropy △n and distance between the substrates holding the liquid crystal! 1
Regarding the product △nci of ild, in the case of the twisted nematic method, the twist angle and the sandwiching angle of the polarizing plate were often 90 degrees in conventional applications such as display elements.In the present invention, the twist angle of the liquid crystal panel using the twisted nematic method It has an orientation direction with an angle of 60° or more and 80" or less, or 100° or more and +20° or less, and the orientation direction matches the absorption axis or polarization axis of the pair of polarizing plates. When used as sunglasses, the minimum A transmittance of 2% or more is desirable without darkening.

By freely setting the twist angle and the sandwiching angle of the polarizing plate within the range of 60° to 80°, or 100° to 120°, the minimum transmittance can be reduced to 2% for ease of use.
You can choose between ~20%. Furthermore, in order to reduce the viewing angle dependence and improve the steepness of the voltage-transmittance characteristics, a large twist angle in the range of 100 to 120 degrees may be used.

Δ11·d was set to a value that reduces viewing angle dependence. Δ
The value of n-d is the eight points of △n-d value at the minimum value of the transmittance on the △n-d dependence curve (Figure 2) of the transmittance of the liquid crystal panel.
It is set at points B and C, but setting at point A, which is the smallest value, is not often used because the distance between M% of the liquid crystal panel becomes too short, and it is generally set at points B and C, which are easier to manufacture. The target is set. However, viewing angle dependence is a big problem with glasses such as electronic sunglasses, so in the present invention, △n・d
It is desirable to use the value at point A, which is the smallest value of .DELTA.n-d may vary by 025, which is the value at point A, centering on point A.

Next, in the present invention, considering the use of the polarizing plate in eyeglass lenses, we also studied the direction of the polarization axis of the polarizing plate and determined the direction so that it would be easier to use as eyeglasses.

In the case of a twisted nematic liquid crystal panel, two polarizing plates are used. At this time, if the directions of the polarization axis of the right eye objective (11 polarizing plate) and the polarization axis of the left eye objective side polarizing plate are greatly misaligned, the transmittance of the reflected light will differ between the right and left eyes, and the actual When I look at the 1st world through the liquid crystal panel, it feels very strange.I put polarizing plates on my right and left eyes, and I looked at the reflected light by changing the angle of the polarization axis of the polarizing plates on my right and left eyes. When the smaller angle between the polarization axes of the left and right polarizing plates was less than 45°, there was less discomfort.

The sense of discomfort is completely eliminated when the angle is 20 degrees or less, and it is desirable that the smaller angle between the polarization axes of the left and right polarizing plates is 20'' or less.

〔Example] Hereinafter, the present invention will be explained in detail based on Examples.

However, the present invention is not limited thereto.

Example-1 FIG. 1 is a front view of a liquid crystal panel in an example of the present invention. The liquid crystal panel 1 was constructed as follows. △ between the board rubbed in the D direction and the board rubbed in the E direction.
A nematic liquid crystal with n (refractive index anisotropy) of 0078 doped with an appropriate amount of a dispensable chiral substance was placed between the substrates 1
The gap agent was sealed with a scatter seal at tilt 7 u. The angle θ between the rubbing direction and E is 110°
And so. The rubbed substrate was coated with a 0-order polarizing plate made of a synthetic resin film base material with an electrically conductive surface made of an ITO film from both sides, with the polarization axis of the polarizing plate aligned with the rubbing direction shown above. I pasted it. A polarizing plate attached to a substrate rubbed in the D direction has its polarization axis aligned in the same direction as the D direction, and a polarizing plate attached to a substrate rubbed in the E direction is
The polarization axis is aligned in the same direction as the E direction. As shown in FIG. 1, the polarization axes of the right eye and the left eye are arranged in the same direction.

The liquid crystal panel obtained in this way is not strong enough to be used as a transmittance variable part of sunglasses, and is easily scratched. I glued it. Outside the adhesive surface 101
An ultraviolet ray curing type Bartco-1 layer was previously applied to the surface of 1 and cured.

The transmittance variable portion obtained as described above had a transmittance of 8.11% when 1i pressure was applied (5V 5tatic) and 35% when it was removed. What are the driving characteristics?

When 2.5V to 3V was applied, the transmittance was saturated to about 8%, and the current consumption was 50 uA. Based on these driving characteristics,
We designed the circuit and determined the light-receiving area of the solar cell.

FIG. 3 is a circuit diagram in one embodiment of the present invention. Solar cell 2, voltage detection circuit 3, oscillation circuit 4, liquid crystal drive circuit 5
, and a liquid crystal panel l. Oscillation circuit 4 is NA
This is a CR oscillation circuit consisting of ND gates 11 and 12, a capacitor 8, and a resistor 9. (The present invention does not limit the fffi type of the oscillation circuit. This is shown as an example.) In addition, the liquid crystal drive circuit 5 includes a NAND gate 13.1 that outputs 1li1.
4 and a driver 15.16. Voltage detection circuit 3
The details are omitted. A power protection capacitor 7 is connected in parallel to the circuit.

The operation will be described below with reference to FIG. The solar cell 2 is
Electromotive force 0.7V at 10,000 Lux per 1cm" iMf direct 7
An amorphous silicon filament capable of extracting 00 μA was used. An output voltage of 3V is sufficient to drive the liquid crystal panel, but in relation to the illuminance, it was set so that an output voltage of 4V or more could be obtained at 10,000 Lux. Therefore, the light-receiving area of the solar cell was set to 6 crn' by using cells with a light-receiving area of 1 cm" connected in series in 6 stages.The detection level of the voltage detection circuit was set to 4■. In this state, the output signal 6 is an off signal, and a voltage of the same phase is applied to the liquid crystal panel l, so it does not light up.When the voltage exceeds 10,000 Lux, the electromotive voltage of the solar cell becomes 4V or more, and the output of the voltage detection circuit 3 signal 6
In order to output an ON signal, the alternating current signal of the first oscillation circuit 4 is applied to the liquid crystal cell from the inverter 15, 16 in reverse phase. The drive frequency is determined by a resistor and a capacitor 8, with a value of several tens to hundreds of t (2 is suitable).The electric and primary f-protection capacitor 7 removes noise and ripple from the power supply, and has a value of about 10 uF. Good. Since the voltage detection circuit 3 is well known in various power supply ICs, battery voltage detection circuits, etc., detailed explanation will be omitted.

Further, as an application of the present invention, it is possible to make improvements such as adding a volume so that the detection level of the voltage detection circuit can be adjusted by the user himself. Furthermore, it is possible to provide hysteresis to the detection level to allow the eye to adjust to changes in light. For example, when you go from a dark place to a bright place, start blocking the light! 'lμ degree is high (voltage is high when it becomes on voltage)
In the opposite case, the brightness should be low (the voltage should be low when the off voltage is reached). This also serves as a measure to prevent sunglasses from flickering under critical conditions.

FIG. 4 is a perspective view of an embodiment of the present invention in which the solar cell 2 and the liquid crystal panel I are assembled into a frame 17. D
The arrow indicates the polarization axis of the polarizing plate on the object side, and the arrow E indicates the polarization axis of the polarizing plate on the eyeball side. The polarization axes of the objective-side polarizing plates were set in the same direction for the right eye and the left eye, and were arranged in the vertical direction. Furthermore, the flat panels of the right-eye transmittance variable section and the left-eye transmittance variable section were not placed on the same plane, but were arranged so that the angle formed by their respective streamlines was 25 degrees. When incorporating the transmittance variable section into the frame, an elastic adhesive was used to avoid stress from the frame. The total weight after assembly was 352 g.

This weight is light enough for eyeglasses, and it is comfortable to wear.

Example-2 1 mm thickness adhered to film-like liquid crystal panel in Example 1
Instead of the flat acrylic plate, lenses made of diethylene glycol bisallyl carbonate (1 resin each) were glued to create a prescription variable transmittance part.

The lens was made by thermal polymerization. In reality, the lenses shown below were glued to the object side and the eyeball side of the liquid crystal panel to obtain the power as a whole (objective rule). Use a lens with an infinite radius of curvature (that is, a flat surface) and a thickness of 5 mm at the center, and the lens S to be glued to the eyeball side is a lens with an infinite radius of curvature on the convex side and a radius of curvature on the concave side of lOcm and a center thickness of 1 mm. The power of the variable transmittance section created in this way is
When I added 111, it was -1.14 diopters.

As in Example 1, the obtained variable transmittance section was incorporated into a frame together with a solar cell and a circuit to obtain sunglasses.

Example 1 row-3 The electrode substrate of the liquid crystal panel itself was made into a lens shape, and the transmittance variable portion was given a dioptric power. One base material of the liquid crystal panel was molded with a convex surface having a radius of curvature of 5 cm and a concave surface having a radius of curvature of 7.5 cm, and a polarizing plate was fixed in the mold.
A small amount of diethylene glycol bisallyl carbonate resin monomer and additives were injected and thermally polymerized. The other base material had a convex surface with a radius of curvature of 7.5 cm and a concave surface with a radius of curvature of 10 cm, and was obtained by thermal polymerization by embedding a polarizing plate in the same manner as the previously obtained base material. Next, the radius of curvature is 7.5
Form ITOIIi on a cm surface by low temperature sputtering,
The surface was subjected to orientation treatment. The rubbing direction of the alignment treatment was performed in accordance with the direction of the absorption axis or polarization axis of the polarizing plate of each base material. After that, glass beads with a diameter of 7μ are scattered over the entire surface in one gap with the surfaces with a radius of curvature of 7.5cm facing each other, and the twist angle of the liquid crystal is adjusted to 70mm using spacers.
It was fixed at °. TN type liquid crystal was inhaled in a vacuum atmosphere through a pre-opened pinhole, the pinhole was closed, and annealing was performed at 60° C. to form a variable transmittance section. The power as a lens was +5.1 diopters.

As in Example 1, the variable transmittance section thus obtained was incorporated into a frame together with a solar cell and a circuit to obtain sunglasses.

Example 4 Electronic sunglasses were constructed in the same manner as in Example 1, except that the circuit configuration used in Example 1 was changed to the circuit configuration shown in FIG. 5. Solar cell 2. LCD panel l.

Electrical power stabilization capacitor 7 and capacitor 18.19,
Resistance 20.21.22.23. transistor 24.25
The liquid crystal drive circuit 5 includes an oscillation circuit 4 made up of a transistor 24 and a liquid crystal drive circuit 5 made up of transistors 24 and 25. Since no voltage is generated when the solar cell 2 is not exposed to light, the capacitor 18.
19. Resistor 20.21.22.23, transistor 2
The oscillation circuit consisting of 4.25 does not oscillate. Therefore, the transmittance variable portion l remains in a high transmittance state. solar cell 2
When the light of about 1000 to 5000 Lux hits,
Although the transistors 24 and 25 oscillate, the peak value of the collector voltage does not reach the ON potential of the liquid crystal, and the transmittance does not change. When the solar cell 2 is exposed to light of approximately 6,000 L or more, the voltage that turns on the liquid crystal is reached and the transmittance begins to change. As the light gets stronger, the transmittance variable part becomes darker, but at 1000
Above 0Lx, it becomes saturated. This differs from the first embodiment in that the transmittance of the variable transmittance section changes continuously depending on the intensity of external light.

Example-5 In order to fix the film-like liquid crystal panel in Example-1, both (
An electronic sun class was constructed in the same manner as in Example 1, except that the following antireflection film was provided on the eyeball side on the hard coat-attached acrylic slope bonded from step 11.

Before adhering to the liquid crystal panel, use a vacuum evaporation method on the hard coat from the synthetic resin base material side.

S i 02 is included/4, and the total film thickness of Zr0z and 5102 is included/4. ZrO2 layer included/4. The uppermost SiO□ layer was made to have a density of 1/4. (Here, large = 520 nm) If the lenses themselves are colored, such as sunglasses, the light absorption of the lenses is large, so the reflection on the eyeball side is very noticeable.In the case of electronic sunglasses, an anti-reflection film is also provided on the eyeball side. This will prevent the reflection from behind from entering your eyes and make it less bothersome.

Example-6 Approximately 100 film-like liquid crystal panels obtained in Example-1 were
It was sandwiched between two cylindrical diethylene glycol bisallyl carbonate plates having a radius of curvature of 1 mm and a thickness of 1 mm, and bonded together using an ultraviolet curable adhesive. The obtained transmittance variable part was installed in a frame so that the cylindrical curve was vertical. The polarizing axis of the polarizing plate used was the same as in Example-1, and the other components were arranged in the same manner as in Example-1.

Example 7 Electronic sunglasses using a transmittance variable part made by bonding a flat acrylic plate to a film-like liquid crystal panel as shown in Example 1 are easier to manufacture than Example 6, which is formed into a single curved surface. There is an advantage that electronic sunglasses can be provided easily and inexpensively. However, sunglasses with flat lenses lose their thickness,
It loses its sense of luxury. In addition, there are significant design constraints,
The drawback is that it is not possible to obtain sunglasses with excellent fashionability.

Therefore, in this embodiment, as shown in FIG. 6, a polycarbonate plate 62 having a curved surface with an appropriate curvature is attached to the front surface of a flat variable transmittance section 61. 63 is a frame, and 64 is a solar cell. Although not shown, a circuit section is also incorporated in the same manner as in Example-1.

The polycarbonate plate 62 may have any shape and size depending on the required design.

The material is not limited to polycarbonate, and a lightweight synthetic resin such as acrylic can be appropriately selected and used.

Furthermore, it can also be colored in an appropriate color according to requirements. The mounting method is not particularly limited, and any method such as gluing, caulking, screwing, etc. may be used. Make it removable.

It can be replaced depending on the purpose, and is effective in improving fashion.

Example 8 FIG. 7 is a partial sectional view showing an example of a fixing structure for fixing a liquid crystal panel to an eyeglass frame.

If the LCD panel and frame are firmly fixed, distortion may occur in the frame depending on the opening and closing of the frame's temples or the size of the user's face. The spacing between the electrodes of the panel changes in one part, resulting in problems such as interference fringes or one-degree unevenness on the liquid crystal panel.

Therefore, in this embodiment, as shown in FIG. 7, a liquid crystal panel 71 and a frame 72 are bonded and fixed using an elastomer 73. In the figure, 74 indicates a liquid crystal layer, and 75 indicates a spacer for maintaining a constant distance between electrodes of the liquid crystal panel. As the elastomer 73, a silicone rubber adhesive was used.

With such a structure, since the silicone rubber adhesive has elasticity, it is possible to absorb distortion occurring in the frame 72.

In the conventional method, when the edge of the LCD panel was inserted into the groove of the frame and firmly fixed with screws, interference fringes appeared on the LCD panel when the frame's temples were opened and closed, but this example In the case of , no visible interference fringes or density unevenness occurred.

Similar results were also obtained when ethylene-propylene rubber was used as the elastomer 73. As the material of the elastomer, an elastic member or adhesive having elasticity sufficient to absorb the distortion of the frame may be used.

Example-9 Figures 8 and 9 show the electrode extraction IjI of the liquid crystal panel.
An example of the structure is shown below.

As mentioned above, the frame may be distorted during normal use, and may also be subjected to impact due to dropping or the like. Therefore, there is a problem that external force is easily applied to the joint between the liquid crystal panel and the frame, and the 'RtN connection part for electrically connecting the liquid crystal panel and the circuit is likely to be disconnected or have poor continuity.

In this example, as shown in FIGS. 8 and 9, the occurrence of disconnection or poor conduction is prevented by making the lead electrodes from one product panel imaginary or having a wide area. .

FIG. 8 shows a case where one eye is provided with electrodes for connection at four locations.

The electrodes were taken out from the transmittance variable section 82 by providing four protrusions on the base material of the liquid crystal panel, and then sputtering an ITO film, which was the counter electrode of the panel, to the protrusions. A solar battery is used as a power source, and a power circuit section 81 is formed together with a drive circuit, and wiring from the circuit passes through the lens frame and extends to the position of the extraction electrode of the transmittance variable section. At this location, the one circuit section and the transmittance variable section are electrically connected. The transmittance variable section used a TN type liquid crystal cell using a plastic film as a base material.

FIG. 9 shows a case where electrodes are provided all around the lens frame.

The electrodes were taken out from the transmittance variable section 92 by spacing the ITO film up to the edge of the liquid crystal panel. In other words, the entire edge of the variable transmittance section serves as an electrode.

A solar battery is used as the power source to form the power supply circuit section 91, and it is connected to a power supply circuit provided around the entire circumference of the lens frame.When the transmittance variable section is incorporated into the lens frame, the ITO at the edge of the liquid crystal panel The membrane and the electrode of the lens frame come into contact and are electrically connected.

The transmittance variable section uses a lens-shaped liquid crystal panel base material, and uses a guest-host method.

In both FIGS. 8 and 9, the electrodes must be connected at two locations in order to be taken out from the opposite electrode of the liquid crystal panel. Although shown simply in the figure, the connection parts 83 and 93 are always connected to one
Paired electrodes are connected.

With the structure shown in FIGS. 8 and 9, the incidence of wire breakage that would otherwise occur when dropped or when excessive force is applied to the frame has been reduced. The rate of decrease is 5% after a drop test (dropping from a height of 1m onto a tile) when an electrode is installed in one location, but it is 1% in the case shown in Figure 8.
, the one shown in FIG. 9 decreased to 0.2%.

[Effects of the Invention] The present invention provides a base t4 of a liquid crystal panel that constitutes a variable transmittance section.
By using synthetic resin and regulating the light-receiving area of the solar cells, the weight of the electronic sunglasses can be reduced to less than 50g. As a result, we were able to obtain a product that could be worn for a long time without causing fatigue, and was sufficiently durable for actual use. Furthermore, by constructing the transmittance variable part with synthetic resin, it has increased strength against breakage and improved safety compared to the case of glass. By setting the orientation direction to be less than or equal to 100° or more than 120°, and by matching the orientation direction with the absorption axis or polarization axis of the pair of polarizing plates, the minimum transmittance value can be adjusted and the transmittance change width can now be set freely. As a result, we were able to obtain a variable transmittance section that can actually be used in electronic sunglasses with variable transmittance. Furthermore, Δ
The value of nd is set as point A in Figure 1 where the corresponding Δnd is the smallest among the minimum values taken by the transmittance in the Δnd dependence curve of the transmittance of the liquid crystal panel, and the twist angle and the angle of the polarizing plate are If the range shown above is set, the viewing angle dependence of the liquid crystal panel will improve, and therefore the unevenness and shading that occur due to changes in the angle at which the liquid crystal panel is viewed due to the movement of the eyeballs will be eliminated, and it will no longer feel uncomfortable even when worn. You can get electronic sunglasses without.

In addition, by setting the smaller angle between the polarizing axis of the objective side polarizing plate of the right eye liquid crystal panel and the polarizing axis of the objective (p11 polarizing plate) of the left eye liquid crystal panel to be less than 45°, the right There is no difference in the amount of reflected light that enters the eye and the left eye, and the outside world no longer looks 3-dimensional, making it a practical electronic sunglass.

As described above, according to the present invention, for the first time, it has been possible to obtain electronic sunglasses that are comfortable to wear for long periods of time.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of a liquid crystal panel according to the present invention. FIG. 2 is a diagram showing the relationship between the transmittance of the liquid crystal panel and Δn−d. FIG. 3 is a circuit diagram showing an embodiment of the circuit in electronic sunglasses according to the present invention. FIG. 4 is a perspective view showing an embodiment of electronic sunglasses according to the present invention. FIG. 5 is a circuit diagram showing another embodiment of the electronic sunglasses according to the present invention. FIG. 6 is a perspective view showing another embodiment of the electronic sunglasses according to the present invention. FIG. 7 is a partial cross-sectional view showing an embodiment of the fixing structure in electronic sunglasses according to the present invention. FIG. 8 and FIG. 9 are diagrams showing an embodiment of the electrode extraction structure in the electronic sunglasses according to the present invention. Value of △n-d when transmittance takes minimum value Rubbing direction of substrate and polarization axis of polarized light Liquid crystal panel Solar cell voltage detection circuit Oscillation circuit Liquid crystal drive circuit Frame or more

Claims (2)

[Claims] (1) In electronic sunglasses that utilize the electro-optical effect of liquid crystals, a) the base material of the liquid crystal panel constituting the transmittance variable section is made of synthetic resin, b) the liquid crystal panel is constructed using a twisted nematic method, and c) the twisted nematic method is used. The twist angle of the liquid crystal panel used is 60° or more and 80° or less, or 100° or more12
have an alignment direction that is 0° or less, and match the absorption axis or polarization axis of the pair of polarizing plates with the alignment direction; d) the polarization axis of the object side polarizing plate of the right eye liquid crystal panel and the polarization axis of the left eye liquid crystal panel Electronic sunglasses, characterized in that the smaller angle between the object-side polarizing plate and the polarization axis is less than 45°, and e) a solar cell is used as a power source for driving a liquid crystal panel. (2) The electronic sunglasses according to claim 1, wherein the light-receiving area S of the solar cell is within a range expressed by the following formula. S≦24cm^2