JP2743464B2 - Electronic sunglasses - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to electronic sunglasses that control light transmittance by utilizing the electro-optic effect of a liquid crystal material.

[Conventional technology]

Sunglasses that have been widely used in the past as variable transmittance sunglasses are those that disperse the photochromic substance in the lens or make a photochromic thin film on the surface of the lens, using the property of coloring by the light of the photochromic substance. there were.

However, sunglasses using such a photochromic substance take a long time from irradiation of light to coloring in response to the light, such as when the headlights of an oncoming vehicle hit while driving a car at night. Has the disadvantage that the photochromic substance deteriorates over time, and the coloring does not disappear even in a dark place.

Many electronic sunglasses using the electro-optic effect of a liquid crystal material have been proposed as a means for solving the above-mentioned drawbacks of the photochromic sunglasses and providing a quick-response sunglass. Such electronic sunglasses are in the limelight as display devices that can be made thinner with low power consumption, and are based on the principles of currently widely used liquid crystal display devices, and the principles are as follows.

That is, a nematic liquid crystal is sealed between two substrates having transparent electrodes formed on the inner surface, and an alignment process is performed on the substrate surface so that liquid crystal molecules are brought into contact with one substrate and with the other substrate. Are oriented so as to be orthogonal to each other. As a result, the liquid crystal molecules in the middle twist spirally,
The incoming light is illuminated 90 degrees. When a polarizing plate is provided outside each of the two substrates, and its polarization axis is made parallel to the orientation direction of the substrate with which each is in contact (that is, the polarization axes of the two polarizing plates are made orthogonal), in that state, Transmits the incoming light. On the other hand, when a voltage is applied to the liquid crystal molecules, the liquid crystal molecules are oriented in a direction parallel to the direction of the voltage (ie, a direction perpendicular to the two substrates), so that the spiral state is eliminated and the incident light is emitted. Without passing through the liquid crystal molecules. However, since the polarization axes of the two polarizing plates are orthogonal to each other, the incident light passing through the liquid crystal molecules is blocked by the polarizing plate on the emission side.

Conversely, if the polarization axes of the two polarizers are set to be parallel, the incident light that has been applied at 90 degrees when no voltage is applied is cut off because it is orthogonal to the polarization axis of the output-side polarizer. In the state where a voltage is applied, incident light is not emitted and can be transmitted.

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

Such a principle is called a twisted nematic method, and most liquid crystal display devices that are currently widely used apply this principle, and most of the electronic sunglasses proposed so far also use this principle. It is an application. In conventional electronic sunglasses, such a twisted nematic liquid crystal panel is installed in a portion corresponding to a conventional lens, the surrounding brightness is detected, and a voltage is applied to the liquid crystal panel in accordance with the amount of light. The non-application is controlled to control the amount of transmitted light. Also, there has been proposed an electronic sunglass which uses a solar cell as a voltage source and applies a voltage to a liquid crystal panel only when the surroundings are bright, that is, only when an electromotive force is generated in the solar cell.

[Problems to be solved by the invention]

In this way, electronic sunglasses using liquid crystal panels
Although many proposals have been made in the past, they have not been put to practical use yet because of the following drawbacks.

That is, conventionally, a glass substrate was generally used as a substrate of a liquid crystal panel. This is because there is a problem of strength and, in the case of a liquid crystal display device, in order to make the display contrast uniform, it is necessary to make the gap between the two substrates enclosing the liquid crystal so-called a cell gap uniform.

However, a liquid crystal panel using such a glass substrate is too heavy to be used for electronic sunglasses, and further requires a circuit and a power supply for driving the liquid crystal panel. And there is a disadvantage that it cannot withstand long-time continuous wearing. As a more serious problem, there is a problem in safety that the glass substrate is easily broken, so that the glass substrate is likely to be broken by an impact and cause serious damage to an eyeball and a face.

Further, in the twisted nematic system, when light is blocked, incident light is blocked almost safely. In the case of a display device, this is preferable in order to improve the display contrast, but in the case of sunglasses, since the field of view has become zero, it cannot be used, especially when driving a car, etc. Is a serious problem because of the danger of serious accidents.

In addition, twisted nematic liquid crystal panels
It is well known that it has a viewing angle dependency, that is, a property that light transmittance changes depending on a viewing angle. In the case of a display device, it is not a big problem if it is installed at a relatively distant place and at an almost constant angle,
In the case of electronic sunglasses, the liquid crystal panel is located very close to the eyeball, and the angle between the line of sight and the liquid crystal panel changes greatly because the eyeball moves when looking around. 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 shading or unevenness, and the feeling of wearing is remarkably deteriorated.

Furthermore, as a problem unique to electronic sunglasses, it is necessary to separately manufacture liquid crystal panels for the right eye and the left eye and attach them separately to the frame, at which time the directions of the polarization axes for the right and left eyes are changed. If it deviates, there is a problem that the transmission amounts of the left and right lights are different, and the wearing feeling is remarkably deteriorated.

This problem can be solved by manufacturing so that the directions of the left and right polarization axes match.However, it may be possible to manufacture safely so that they can be made by highly skilled workers. This is not possible when manufacturing at low cost.

As described above, electronic sunglasses using a liquid crystal panel have a problem that they cannot be put into practical use due to various factors, regardless of the fact that many engineers have long proposed and conducted research.

An object of the present invention is to solve such various problems that have made practical use difficult, and to provide electronic sunglasses that can withstand practical use.

[Means for solving the problem]

The electronic sunglasses of the present invention are electronic sunglasses utilizing the electro-optical effect of liquid crystal, wherein the electronic sunglasses have a transmittance variable portion configured using a twisted nematic liquid crystal panel made of a synthetic resin as a base material, and the liquid crystal panel has a twist angle. 60 ° or more and 80 ° or less, or 100
The alignment direction is not less than 120 ° and not more than 120 °, and the absorption direction or the polarization axis of the pair of polarizing plates is matched with the alignment direction.

In addition, the liquid crystal panel for the right eye has a variable transmittance portion composed of two twisted nematic liquid crystal panels made of synthetic resin as base materials, and the polarization axis of the objective side polarizing plate of the liquid crystal panel for the right eye and the liquid crystal panel for the left eye. The smaller angle of the angle formed between the polarization axis of the objective-side polarizing plate and the polarization axis is less than 45 °.

Further, a solar cell is used as a power supply for driving the liquid crystal panel.

Also, the light receiving area S of the solar cell is in a range represented by the following equation.

S ≦ 24 cm ² [Effect] The weight of the spectacles is not limited to sunglasses, but has an important meaning when actually worn. That is, as the weight increases, the feeling of wearing the glasses deteriorates, and it becomes difficult to wear them for a long time. Desirable weight as glasses is 50 g or less, when using a synthetic resin base material for the lens in ordinary glasses, 30
g. Since electronic sunglasses are different from ordinary glasses, they are composed of a liquid crystal panel, a power supply unit, a drive-control circuit unit, their mounting parts, and a large number of parts. Therefore, it is necessary to limit the weight of each part as much as possible. desirable.

In the present invention, as a method of reducing the weight of the electronic sunglasses, a careful investigation was conducted on a liquid crystal panel and a solar cell which are considered to be the most effective in reducing the weight of the constituent parts.

The following results were obtained for the liquid crystal panel. When a synthetic resin substrate and a glass substrate were used as the substrate of the liquid crystal panel, it was found that the glass substrate was about twice as heavy with the same shape and thickness. When actually measuring the weight a prototype liquid crystal panel in a lens shape of the sunglasses, the variable transmittance portion at which the lens portion as the dimension thickness 2 mm, with an area 26cm ^2, when the glass substrate 16.2g synthetic resin substrate At that time, it weighed 7.9 g. From this, it is possible to reduce the weight of about 16 g with both eyes by simply changing the base material from glass to synthetic resin in the liquid crystal panel used in actual electronic sunglasses.

Since the liquid crystal panel is used as a variable transmittance portion of electronic sunglasses, that is, as a lens portion, it is necessary to consider not only weight but also safety. When the base material of the liquid crystal panel is glass, it is very dangerous when broken. Therefore, in order to obtain safety, the thickness of the variable transmittance portion must be set to be thicker than that of the synthetic resin. This also has a negative impact on weight.

Various methods can be used to use a synthetic resin substrate as the substrate of the liquid crystal panel. For example, a transparent electrode film such as an ITO film is directly provided on a synthetic resin base material, alignment treatment is performed, liquid crystal is sealed between synthetic resin base materials fixed with spacers, and a polarizing plate is attached. How to form a panel. In addition, if a film-shaped liquid crystal panel whose base material is made of a synthetic resin film is used, or if the film-shaped liquid crystal panel is concerned in terms of strength, a separately formed synthetic resin base material may be used. There is a method in which a transparent adhesive is applied to one or both sides of the liquid crystal panel to form a liquid crystal panel and a variable transmittance portion. However, it is sufficient that most of the variable transmittance portion is formed of a synthetic resin. The shape of the substrate may be a flat plate or a plate having a curvature. When it is also desired to correct vision, it is also possible to use a lens-shaped substrate having a curvature that matches the power.

The weight of the solar cell 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 cell and the power required to drive the liquid crystal panel, but the upper limit is limited by weight.

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

The frame of sunglasses consists of a frame that supports the variable transmittance part and a vine part that is used for ears. Both the cell frame and the metal frame are light and weigh about 17 g.

The weight of the transmittance variable part depends on its area and thickness,
Since the area of ordinary sunglasses does not change at around 26 cm ² , it mainly depends on the thickness. When a liquid crystal panel is made of synthetic resin, it is easily deformed by external force.
2mm is needed. This was found as a result of various investigations by applying external force to the liquid crystal panel. Therefore, as described above, the weight of the liquid crystal panel as the transmittance variable portion is about 8 g per eye,
For both eyes, it will be around 16g.

The total weight of the frame and the transmittance variable section is about 33 g, but it is desirable that the total weight is 50 g or less in order to obtain sunglasses with a good feeling of wearing, so the remaining parts such as solar cells, circuits, solar cells The total weight of the circuit mounting part is 50 g
The condition is -33g = 17g or less.

It is possible to reduce the weight of the circuit to less than 1g by integrated technology, so the solar cell and circuit
It is necessary to keep the weight below g.

As the light receiving area of the solar cell increases, its mounting portion also increases. The measurement results show that even when the mounting portion is formed of a lightweight synthetic resin, the weight of the mounting portion and the weight of the solar cell will be substantially the same if the mounting portion is required to have practical strength. In other words, the weight of the solar cell is 8g
If it is below, the weight of the electronic sunglasses with a good wearing feeling can be obtained.

Solar cells with amorphous silicon formed on inexpensive and widely used glass substrates weigh 1m, which is relatively thick
Since the thickness of the solar cell is about 0.3 g per 1 cm ² with a thickness of m-1.2 mm, the light receiving area of the solar cell is desirably about 24 cm ² or less.

Of course, the weight values described so far vary depending on the material and size of each part, but the average value is 24 cm
Determined ² . Further, in the design, a value higher than this is not preferable because the area of the solar cell is too large.

Further, in the present invention, the viewing angle dependency of the twisted nematic liquid crystal panel and the upper and lower limits of the variable transmittance are improved to provide a liquid crystal panel that can be used practically as electronic sunglasses.

 Improvements were mainly made for the following two points.

1. Twist angle in the twisted nematic method and the pinch angle of the polarizing plate. 2. Product Δnd of the refractive index anisotropy Δn and the distance d between the substrates holding the liquid crystal. Twisted angle and the polarizing plate in the twisted nematic method. The conventional scissor angle was 90 ° for many applications such as display devices. In the present invention, the twist angle of the liquid crystal panel using the twisted nematic method has an orientation direction of 60 ° or more and 80 ° or less, or 100 ° or more and 120 ° or less, and the orientation direction and the absorption axis or the polarization axis of the pair of polarizing plates. Was matched. When used as sunglasses, a minimum transmittance of 2% or more is desirable without darkening. Set the twist angle and the scissor angle of the polarizing plate at 60 ° or more and 80 ° or less, or 100 ° or more and 120 °
By freely setting the following ranges, the minimum transmittance that is easy to use in use can be selected from 2% to 20%. In order to further reduce the viewing angle dependence and improve the steepness of the voltage-transmittance characteristics, a large twist angle of 100 to 120 is required.
The range of ° may be used.

Δn · d is set to a value that reduces the viewing angle dependency. Δ
The value of n · d is the Δn · d value A point at the minimum value of the transmittance in the Δn · d dependency curve (FIG. 2) of the transmittance of the liquid crystal panel,
The setting at the point A, which is the smallest value, is set at the points B and C. The distance between the electrodes of the liquid crystal panel is too short and is not often used, and is generally used at the points B and C which are easy to manufacture. Is set to However, in eyeglasses such as electronic sunglasses, the viewing angle dependency becomes a significant problem, and therefore, in the present invention, Δn · d
It is desirable to use the value at point A, which is the smallest value of. The value of Δn · d may vary about point A by about 0.25 of the value of point A.

Next, in the present invention, considering the use of a polarizing plate as a spectacle lens, the direction of the polarization axis of the polarizing plate was also studied to determine a direction that would make it easier to use as spectacles.

In the case of a twisted nematic liquid crystal panel, two polarizing plates are used. At this time, if the direction of the polarization axis of the objective-side polarizing plate for the right eye and the direction of the polarization axis of the objective-side polarizing plate for the left eye are significantly different, the transmittance for reflected light differs between the right eye and the left eye,
When you actually look at the outside world through the liquid crystal panel, you feel a sense of strangeness. When the polarizing plate was applied to the right and left eyes, and the angle of the polarizing axis applied to the right and left eyes was changed and the reflected light was viewed, the angle between the polarizing axes of the left and right polarizing plates was determined. When the smaller angle was less than 45 °, there was less discomfort. The sense of incongruity is completely eliminated when the angle is 20 ° or less, and the smaller one of the angles formed by the polarization axes of the left and right polarizers is 20 °.
It is desirable that:

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Embodiment 1 FIG. 1 is a front view of a liquid crystal panel according to an embodiment of the present invention. The liquid crystal panel 1 was configured as follows. A nematic liquid crystal to which an appropriate amount of a right-handed chiral substance is added such that Δn (refractive index anisotropy) is 0.078 between a substrate rubbed in the D direction and a substrate rubbed in the E direction is applied at a distance between the substrates of 7 μm. Then, the gap agent was sealed by scattering seal.
The angle θ between the rubbing directions D and E was 110 °. As the rubbed substrate, a synthetic resin film substrate having an electrically conductive surface made of an ITO film was used. Next, put the polarizing plate from both sides,
The polarizing plate was attached so that the polarization axis of the polarizing plate coincided with the rubbing direction described above. The polarizing plate to be attached to the substrate rubbed in the D direction is aligned with the polarization axis in the same direction as the D direction, and the polarizing plate to be attached to the substrate rubbed in the E direction is in the same direction as the E direction.
The polarization axes are aligned. 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 1mm thick because it is weak in strength and easily scratched when used as a variable transmittance part of sunglasses
Were bonded from both sides using an ultraviolet-curing adhesive. An ultraviolet-curable hard coat layer was provided and cured on the outer surface other than the adhesive surface.

The transmittance variable section obtained as described above had a transmittance of 8.11% when a voltage was applied (5 V Static) and 35% when the voltage was released. The driving characteristics were such that when 2.5 V to 3 V was applied, the transmittance was saturated to about 8%, and the current consumption was 50 μA. Circuit design was performed based on these drive characteristics, and the light receiving area of the solar cell was determined.

FIG. 3 is a circuit diagram in one embodiment of the present invention. It comprises a solar cell 2, a voltage detection circuit 3, an oscillation circuit 4, a liquid crystal drive circuit 5, and a liquid crystal panel 1. The oscillation circuit 4 is NA
This is a CR oscillation circuit including ND gates 11 and 12, a capacitor 8, and a resistor 9. (The present invention does not limit the type of the oscillation circuit.
This is shown as an example. In addition, the liquid crystal drive circuit 5 includes NAND gates 13 and 14 for controlling the output and drivers 15 and 16. Details of the voltage detection circuit 3 are omitted. The power supply protection capacitor 7 is connected in parallel with the circuit.

The operation will be described below with reference to FIG. The solar cell 2 is
Amorphous silicon made capable of extracting an electromotive force of 0.7 V and a current value of 700 μA at 10,000 Lux per cm ² was used. An output voltage of 3V is enough to drive the liquid crystal panel, but it was set so that output voltage of 4V or more could be obtained at 10,000 Lux in relation to illuminance. Therefore, the light receiving area of a solar cell is 1 cm ² per cell.
A cell having a light receiving area of 6 was connected in series in six stages, and the cell area was set to 6 cm ² . When the detection level of the voltage detection circuit is set to 4 V, in this state, the output signal 6 is an off signal, and the same phase voltage is applied to the liquid crystal panel 1 so that the liquid crystal panel 1 is not turned on. 10,000 Lu
When the voltage exceeds x, the electromotive voltage of the solar cell becomes 4 V or more, and the output signal 6 of the voltage detection circuit 3 outputs an ON signal. Is applied to The driving frequency is determined by the resistor 9 and the capacitor 8, and several tens to several hundreds Hz are appropriate. The power supply protection capacitor 7 removes noise and ripples to the power supply, and is preferably about several tens of μF. Since the voltage detection circuit 3 is well known in various power supply ICs, battery voltage detection circuits, and the like, detailed description is omitted.

Further, as an application of the present invention, it is possible to make an improvement such as adding a volume so that the user can adjust the detection level of the voltage detection circuit. Further, the detection level may be provided with hysteresis so that the eye can be used to the change in light. For example, when going from a dark place to a bright place, the illuminance at the start of shading is high (the voltage is high when the voltage is on), and the reverse is low (the voltage is low when the voltage is off).
To do. This is also a measure to prevent sunglasses from flickering under critical conditions.

FIG. 4 is a perspective view showing one embodiment of the present invention, in which the solar cell 2 and the liquid crystal panel 1 are incorporated in a frame 17. D
Arrows indicate the polarization axis of the polarizing plate on the objective side, and arrow E indicates the polarization axis of the polarizing plate on the eyeball side. The polarization axes of the objective-side polarizing plate were set to be the same direction for the right eye and the left eye, and were arranged in the vertical direction. Further, the flat panels of the transmittance variable section for the right eye and the transmittance variable section for the left eye were not arranged on the same plane, but were arranged so that the angle between the streamlines was 25 °. When the transmittance variable portion was incorporated in the frame, an elastic adhesive was used so that stress from the frame was not applied. The total weight after assembly was 35.2 g. This weight is light as glasses,
The wearing feeling is at a good level.

Example 2 1 mm in thickness adhered to a film-like liquid crystal panel in Example 1.
In place of the flat acrylic plate, a lens made of diethylene glycol bisallyl carbonate resin was adhered to form a graded transmittance variable portion. The lens was produced by thermal polymerization. Actually, the following lenses are adhered to the objective side and the eyeball side of the liquid crystal panel so as to obtain a power as a whole. The lens bonded to the objective side has a convex radius of curvature of 13 cm and the concave surface has an infinite radius of curvature (that is, a flat surface) and a center thickness of 5 mm. The lens bonded to the eyeball side has an infinite convex radius of curvature. A lens with a center thickness of 1 mm and a concave radius of curvature of 10 cm was used. The frequency of the thus-obtained transmittance variable portion was measured to be -1.14 diopters.

The obtained transmittance variable section was assembled into a frame together with a solar cell and a circuit as in Example 1 to obtain sunglasses.

Example 3 The electrode substrate itself of the liquid crystal panel was formed into a lens shape, and the transmittance variable portion was provided with power. One substrate of the liquid crystal panel forms a mold with a convex surface with a radius of curvature of 5 cm and a concave surface with a radius of curvature of 7.5 cm.A polarizing plate is fixed in the mold, and a small amount of diethylene glycol bisallyl carbonate resin monomer and additives are added. Poured and obtained by thermal polymerization. The other substrate has a convex curvature radius of 7.5 cm and a concave curvature radius of 10 cm.
As in the case of the substrate obtained above, a polarizing plate was embedded and obtained by thermal polymerization. Next, an ITO film was formed on the surface having a radius of curvature of 7.5 cm by low-temperature sputtering, and the surface was subjected to an orientation treatment.
The rubbing direction of the alignment treatment was performed in accordance with the direction of the absorption axis or the polarization axis of the polarizing plate of each substrate. Then, the surface with a radius of curvature of 7.5 cm is opposed to the gap 7 μm in diameter.
The glass beads were scattered throughout, and fixed by a spacer so that the twist angle of the liquid crystal became 70 °. After the TN type liquid crystal was sucked in a vacuum atmosphere from the previously opened pinhole and the pinhole was closed, annealing was performed at 60 ° C. to obtain a transmittance variable portion. The power as a lens is +5.1
It was diopter.

The thus-obtained transmittance variable section was assembled into a frame together with a solar cell and a circuit in the same manner as in Example 1 to obtain sunglasses.

Example 4 An electronic sunglass was constructed in exactly 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. A solar cell 2, a liquid crystal panel 1, a power supply stabilizing capacitor 7 and capacitors 18, 19, resistors 20, 21, 22, 23, an oscillation circuit 4 including transistors 24 and 25, and a transistor 24;
And a liquid crystal driving circuit 5 comprising the liquid crystal driving circuit 25. Solar cell 2
Since no voltage is generated when light does not hit the, capacitors 18, 19, resistors 20, 21, 22, 23, transistor 24,
The oscillation circuit consisting of 25 does not oscillate. Therefore, the transmittance variable section 1 remains in a state of high transmittance. 1000 for solar cell 2
When light of ~ 5000Lux hits, transistors 24 and 2
5 oscillates, but the peak value of the collector voltage does not reach the ON potential of the liquid crystal, and the transmittance does not change. About 6000Lx for solar cell 2
When the above light is applied, the voltage reaches a voltage at which the liquid crystal is turned on, and the transmittance starts to change. As the light intensity further increases, the transmittance variable portion becomes darker, but becomes saturated at 10,000 Lx or more. This is different from the first embodiment in that the transmittance of the transmittance variable section changes continuously depending on the intensity of external light.

Example-5 In Example-1, except that the following antireflection film was provided on the eyeball side on the hardcoat of the acrylic plate with hardcoat adhered from both sides to fix the film-shaped liquid crystal panel, Electronic sunglasses were constructed in the same manner as in Example 1.

Before bonding to the liquid crystal panel,
Using a vacuum evaporation method, from the synthetic resin substrate side, SiO ₂ enters / 4,
The total thickness of ZrO ₂ and SiO ₂ is / 4, the ZrO ₂ layer is / 4, and the top layer is
The SiO ₂ layer was filled / 4. When the lens itself is colored like sunglasses, the light absorption of the lens is large, so that the reflection on the eyeball side is large and conspicuous. Even in the case of electronic sunglasses, just provide an antireflection film on the eyeball side,
Reflection from behind is not visible to the eyes and is not bothersome.

Example -6 The film-shaped liquid crystal panel obtained in Example 1 was about 100 m long.
It was sandwiched between two cylindrical plates of diethylene glycol bisallyl carbonate having a radius of curvature of 1 mm and having a thickness of 1 mm, and bonded using an ultraviolet curable adhesive. The obtained transmittance variable section was arranged so that the curve of the cylinder was in the vertical direction, and was incorporated into a frame. The polarizing axis of the polarizing plate used was the same as in Example-1.
And the others were arranged in the same manner as in Example 1.

Example -7 An electronic sunglass using a transmittance variable portion in which a flat acrylic plate is adhered to a film-like liquid crystal panel as shown in Example -1 is manufactured in comparison with Example -6 in which a curved surface is formed. There is an advantage that easy and inexpensive electronic sunglasses can be provided. However, in the case of sunglasses having a flat lens portion, the thickness of the sunglasses is lost, and the sense of quality is lost. In addition, there is a drawback that design restrictions are great and sunglasses with excellent fashion cannot be obtained.

Therefore, in the present embodiment, as shown in FIG. 6, a polycarbonate plate 62 formed with a curved surface having an appropriate curvature was attached to the front surface of the flat transmittance variable portion 61. 63 is a frame, and 64 is a solar cell. Although not shown, the circuit unit is also incorporated in the same manner as in the first embodiment.

The polycarbonate plate 62 may have an appropriate shape in accordance with a required design, and may have any size.
The material is not limited to polycarbonate, and a lightweight synthetic resin such as acryl can be appropriately selected and used.
Further, it can be colored into an appropriate color as required. The mounting method is not particularly limited, and any method such as adhesion, caulking, and screwing may be used. If it can be removed, it can be replaced according to the application, which is effective in further improving fashionability.

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

When the LCD panel and the frame are firmly fixed, the frame will be distorted depending on the size of the user's face when opening and closing the vine of the frame and the size of the user's face. The distance between the electrodes partially changes, resulting in a problem that interference fringes and uneven density occur on the liquid crystal panel.

Therefore, in the present embodiment, as shown in FIG. 7, the liquid crystal panel 71 and the frame 72 are joined and fixed using the elastomer 73. In the figure, reference numeral 74 denotes a liquid crystal layer, and 75 denotes a spacer for keeping the distance between the electrodes of the liquid crystal panel constant.
As the elastomer 73, a silicone rubber-based adhesive was used.

With such a structure, since the silicone rubber-based adhesive has elasticity, the strain generated in the frame 72 can be absorbed.

As in the past, when the edge of the liquid crystal panel was sandwiched in the groove of the frame and fixed firmly with screws, when the vine of the frame was opened and closed, interference fringes occurred on the liquid crystal panel. In the case of No. 1, no interference fringes or density unevenness that could be visually confirmed were generated.

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

Embodiment 9 FIGS. 8 and 9 show an embodiment of a structure for taking out electrodes of a liquid crystal panel.

As described above, the frame may be distorted in a normal use state, and may be subjected to an impact due to a drop or the like. For this reason, there is a problem that an external force is easily applied to a joint portion between the liquid crystal panel and the frame, and a connection portion of an electrode for electrically connecting the liquid crystal panel and a circuit is liable to be disconnected or a poor conduction.

In the present embodiment, as shown in FIGS. 8 and 9, the number of lead-out electrodes from the liquid crystal panel or the area of the lead-out electrode is increased to prevent disconnection or poor conduction.

FIG. 8 shows a case in which electrodes for connection at four locations are provided in one eye.

The method of taking out the electrodes from the transmittance changing portion 82 was performed by providing four projections on the base material of the liquid crystal panel and providing an ITO film, which is a counter electrode of the panel, to the projections by sputtering. A power supply circuit section 81 is formed together with a drive circuit using a solar cell as a power supply, and wiring from the circuit is extended through a lens frame to a position of an extraction electrode of a transmittance variable section. At this location, the 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 electrode was taken out from the transmittance variable section 92 by sputtering an ITO film to the edge of the liquid crystal panel.
That is, the entire edge of the transmittance variable section is an electrode. A power supply circuit unit 91 is formed using a solar cell as a power supply, and is connected to electrodes provided on the entire periphery of the lens frame. When the transmittance variable section is incorporated in the lens frame, the ITO film on the edge of the liquid crystal panel and the electrode of the lens frame come into contact with each other and are electrically connected.

The transmittance variable section uses a lens-like liquid crystal panel base material and uses a guest-host system.

In both FIGS. 8 and 9, two electrodes must be connected so that the electrodes can be taken out of the counter electrode of the liquid crystal panel. Although shown in a simplified manner in the figure, a pair of electrodes are always connected to the connection portions 83 and 93.

With the structure as shown in FIG. 8 and FIG. 9, the occurrence rate of disconnection failure that occurred when the frame was dropped or a force was forcibly applied to the frame was reduced. The rate of the drop was 5% when the disconnection rate after the drop test (dropping from a height of 1 m on the tile) when the electrode was provided in one place was 1% in FIG.
%, And that of FIG. 9 decreased to 0.2%.

〔The invention's effect〕

In the present invention, the weight of the electronic sunglasses can be reduced and the weight can be reduced to 50 g or less by using a synthetic resin as the base material of the liquid crystal panel constituting the variable transmittance portion and defining the light receiving area of the solar cell. Therefore, it was possible to obtain a material which was not tired even when worn for a long time, and which could sufficiently withstand actual use. Furthermore, by constituting the variable transmittance portion with a synthetic resin, the strength against destruction is increased and the safety is improved as compared with the case of glass.

Further, in the twisted nematic method, the twist angle was 60 ° or more and 80 ° or less, or the orientation direction was 100 ° or more and 120 ° or less, and the orientation direction was matched with the absorption axis or the polarization axis of the pair of polarizing plates. As a result, the value of the minimum transmittance can be adjusted, and the transmittance change width can be freely set. As a result, it was possible to obtain a transmittance variable portion that can be used for electronic sunglasses whose transmittance is actually variable. Further, the value of Δnd is defined as the point A in FIG. 1 where the corresponding Δnd is minimum among the minimum values of the transmittance in the Δnd dependency curve of the transmittance of the liquid crystal panel, and the twist angle and the sandwich angle of the polarizing plate are defined as With the above range, the viewing angle dependency of the liquid crystal panel is improved, and therefore,
The unevenness and shading caused by the change in the angle of view of the liquid crystal panel due to the movement of the eyes disappears, and electronic sunglasses that do not cause any discomfort even when worn can be obtained.

Further, by setting the smaller one of the angles formed by the polarization axis of the objective-side polarizing plate of the liquid crystal panel for the right eye and the polarization axis of the objective-side polarizing plate of the left-eye liquid crystal panel to less than 45 °, the right eye This eliminates the difference in the amount of reflected light incident on the left and right eyes and eliminates the sense of incongruity that the external world looks three-dimensional.

As described above, according to the present invention, it was possible to obtain, for the first time, electronic sunglasses that can be worn for a long time without discomfort.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a liquid crystal panel according to the present invention. FIG. 2 is a diagram showing the relationship between the transmittance of a liquid crystal panel and Δn · d. FIG. 3 is a circuit diagram showing one embodiment of a circuit in the electronic sunglasses according to the present invention. FIG. 4 is a perspective view showing an embodiment of the electronic sunglasses according to the present invention. FIG. 5 is a circuit diagram showing another embodiment of the circuit in 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 sectional view showing one embodiment of a fixing structure in the electronic sunglasses according to the present invention. 8 and 9 are views showing an embodiment of an electrode take-out structure in the electronic sunglasses according to the present invention. A, B, C... Value of Δn · d when transmittance takes a minimum value E, D... Rubbing direction of substrate and polarization axis of polarizing plate 1... Liquid crystal panel 2... Solar cell 3. Detection circuit 4 Oscillation circuit 5 Liquid crystal drive circuit 17 Frame

Continuation of the front page (31) Priority claim number JAN 63-67754 (32) Priority date May 23, 1988 (33) (33) Priority country Japan (JP) (31) Priority claim number No. 63-67755 (32) Priority date May 23, 1988 (33) (33) Priority claiming country Japan (JP) (31) Priority number No. 63-67756 (32) Priority date Showa 63 (1988) May 23 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 63-125171 (32) Priority date May 63, 1988 (1988) (33) Priority Claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 63-125172 (32) Priority date May 23, 1988 (33) (33) Priority claiming country Japan (JP) (31) Priority claim Number Japanese Patent Application No. 63-125174 (32) Priority Date May 23, 1988 (33) Priority Country Japan (JP)

Claims (4)

(57) [Claims] An electronic sunglass utilizing an electro-optic effect of a liquid crystal, comprising: a transmittance variable portion formed by using a twisted nematic liquid crystal panel made of a synthetic resin as a base material, wherein the liquid crystal panel has a twist angle of 60 °. More than 80 ° or less, or 100 °
Electronic sunglasses having an orientation direction of at least 120 ° and having the absorption direction or the polarization axis of the pair of polarizing plates coincide with the orientation direction. 2. An electronic sunglass using an electro-optic effect of liquid crystal, comprising a variable transmittance portion composed of two twisted nematic liquid crystal panels made of synthetic resin as a base material, and a liquid crystal panel for the right eye. Electronic sunglasses, wherein the smaller one of the angles formed between the polarization axis of the objective-side polarizing plate and the polarization axis of the objective-side polarizing plate of the liquid crystal panel for the left eye is less than 45 °. . 3. An electronic sunglass according to claim 1, wherein a solar cell is used as a power supply for driving said liquid crystal panel. 4. The electronic sunglass according to claim 3, wherein the light receiving area S of the solar cell is in a range represented by the following equation. S ≦ 24cm ²