JPS6161129A - Liquid crystal spectacles - Google Patents

Abstract

PURPOSE:To compensate the change of the refractive index of liquid crystal due to temperature change on the basis of the orientation control of the liquid crystal by forming an applied voltage control means for variably controlling a voltage applied to the liquid crystal on the basis of detecting signals from a liquid crystal temperature detecting means and a temperature detecting means. CONSTITUTION:A pair of liquid crystal spectacles 1 are constituted with a spectacle part and a control part 3 for compensating the change of a focal distance due to the change of a refractive index based upon the temperature change of liquid crystal of the spectacle part. The right and left lens parts 4 of the spectacle part are formed by sealing liquid crystal 11a, 11b between a common transparent plate 8 and projected surface-like transparent plates 10a, 10b through spacers 9a, 9b respectively. A liquid crystal temperature detected by a temperature sensor 16 is compared with a reference value obtained when a prescribed focal distance is previously set up through a temperature detection processing part 17 by a comparator 18 and the compared result is inputted to an applied voltage control circuit 19. The circuit 19 controls the voltage to be applied to the liquid crystal 11a, 11b by a variable voltage output circuit 21 through a characteristic compensating circuit 20. Consequently, the orientation of the liquid crystal is controlled and the change of the refractive index of the liquid crystal can be compensated by the temperature change.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to liquid crystal glasses that can automatically prevent the focal length 1i111 from deviating from a preset value due to temperature changes.

[Technical backstory of the invention and its problems] When the ability to adjust the focal length of the eyeballs deteriorates, such as with presbyopia, it is necessary to wear two types of glasses with different focal lengths, one for near distance and one for far distance. I try to use it, but it is inconvenient because I have to change the hook depending on the situation. In addition, some eyeglass lenses have regions with different focal lengths in a part of the upper part of the lens, so that they can cover appropriate ranges at both near and far distances. is part of the visual field [J, so it is difficult to see.

Further, when the crystalline lens is removed due to a disease such as cataract, it is inconvenient that several types of glasses with different focal lengths must be prepared and used depending on the situation.

For this reason, as disclosed in Japanese Patent Publication No. Sho 58-50339jQ, there is a system that can deal with this problem by using a voltage-controlled variable focal length lens using a liquid crystal.

The above conventional example is very convenient because it can be operated with low voltage and low power consumption, but when used as glasses, the surrounding temperature changes greatly depending on the season.
In addition, the temperature varies greatly depending on whether it is outdoors in summer or winter, or indoors in a cold room.

Therefore, due to temperature changes, the refractive index of the liquid crystal changes, causing the focal length to deviate from a preset value, resulting in the inconvenience that it becomes impossible to see clearly.

Therefore, the above two conventional examples have a drawback that the applied voltage may need to be adjusted every time there is a change in the ambient temperature.

[Objective of the Invention 1] The present invention was developed in view of the above-mentioned fish lυ, and it is an object of the present invention to provide liquid crystal glasses having a compensation means so that a preset focal length does not change even if the surrounding temperature changes. With the goal.

[Summary of the Invention 1 The present invention provides a liquid crystal temperature detecting means, which variably controls the voltage applied to the liquid crystal based on the output signal of the detecting means, and sets the refractive index of the liquid crystal due to temperature changes. Try to maintain the value.

[Embodiment 1 of the invention Hereinafter, the present invention will be specifically explained with reference to Eko.

FIGS. 1 to 4 relate to a first embodiment of the present invention.
The figure shows the configuration of the first embodiment, Fig. 2 shows the appearance of the first embodiment, Fig. 3 shows a plan view of Fig. 2, and Fig. 4 shows the voltage output from the applied voltage control circuit. This figure shows how the focal length of liquid crystal glasses, which exhibits temperature dependence, is maintained at a constant value by applying an electric current.

The liquid crystal glasses 1 of the first embodiment having the appearance shown in FIG. 2 include a glasses section 2 and a control section 3 that compensates for changes in focal length due to changes in refractive index accompanying temperature changes of the liquid crystal in the glasses section 2.
It consists of

The above-mentioned glasses part 2 has a structure shown in FIG. The left and right parts are fixed and rotatable at both ends of both lens frames.
The control unit 3 is provided, for example, on one lens frame side.

The upper left lens portion 4 or the right lens portion 5 has a structure as shown in an enlarged scale in FIG. 1, for example.

A common transparent plate 8 formed of a glass plate or the like is fixed to the frame 6, and spacers 9a are provided on both sides thereof.

Liquid crystals 11a and 11b having the same characteristics are sealed between, for example, convex transparent plates 10a and 10b with a lens 9b interposed therebetween, thereby forming variable focal length lenses 12a and 12b.

In each of the lenses 12a and 12b, when no voltage is applied, the liquid crystal molecules are aligned parallel to the transparent plate 8,
Moreover, the directors (coinciding with the optical axis) indicating the average orientation direction of the liquid crystal are orthogonal to each other in lenses 12a and 12b.In other words, the orientation direction of each liquid crystal molecule in each lens 12a and 12b is rubb in the direction of the arrow A in Figure 1 and in the direction B with a vertical line in this direction A.
in.

The orientation directions A and B are perpendicular to the direction of incident light.

Transparent electrodes 13a and 13b are provided on both sides of the common transparent plate 8 by coating with Sn02, etc., and each transparent plate 10a formed of a glass plate or the like facing the transparent plate 8 is provided with transparent electrodes 13a and 13b.
, 10b are also provided with transparent electrodes 14a, 14b.

The two outer electrodes 14a and 14b are electrically connected to each other by a lead wire or the like and are connected to a ground terminal.

Further, both inner electrodes 13a and 13b are also connected to each other.

Both variable focal length lenses 12a and 12b having the above structure constitute a variable focal length lens that does not require the use of a polarizing plate, as described below.

The incident light can be decomposed into two mutually orthogonal polarized components, namely, an alignment direction in the direction of the arrow in the lens 12a in FIG. 1 and an alignment direction in the direction of the arrow B in the lens 12b. First, the arrow Δ of the lens 12a, which is one component of the necessary light,
When a polarized light component whose orientation direction is flat 1j is incident on the lens 12a, this light ray component becomes an extraordinary ray with respect to the lens 12a.

Therefore, when a voltage is applied to the lens 12a in this state, the liquid crystal molecules gradually change their orientation in a direction perpendicular to the electrode surface according to the voltage, so that only the lens 12a refracts the extraordinary ray component. The ratio changes continuously from the value for extraordinary light to the value for ordinary light, and is affected by the variable focal length.

The extraordinary light component for this lens 12a is the lens 12b.
Since it becomes an ordinary light component, the refractive index of Mika 4J does not change and is not affected by the variable focal length. Therefore, keep going straight. On the other hand, the other incident light component, that is, the component corresponding to ordinary light with respect to the lens 12a, has no change in the apparent refractive index and is not affected by the variable focal length effect in the lens 12a, but it becomes extraordinary light in the lens 12b. As the corresponding components change, the refractive index of the lens changes, similar to when extraordinary light enters the lens 12a (described above), and the effect of changing the focal length is affected. Lens 12a and lens 1
Since the same voltage is applied to 2b, the effect of varying the focal length 111 equal to n is exerted on each polarization component. Therefore, two variable focal length lenses 12a, 1
By overlapping the optical axes of the liquid crystals 11a and 11b in 2b so that they are perpendicular to U, the lens can function as a variable focal length lens for polarized light in any direction (t'7), and a polarizing plate can be used. A lens is constructed in which the focal length can be varied regardless of the polarization direction of incident light without causing any damage. In other words, a bright lens with high light utilization efficiency is constructed, even for natural light that is not linearly polarized, without using a polarizing plate.

Note that each of the variable lenses 12a and 12b has liquid crystals 11a and 11b.
The magnitude of lb is different between the center and the periphery, and the electric field when a certain voltage is applied is different between the center and the periphery.
It is known that the refractive index depends on the applied voltage but not on the applied electric field, and by controlling the applied voltage, it is generally possible to realize a lens with a uniform refractive index change.

A thermistor is provided at the periphery of one of the lens parts (for example, 4). Thermal light bulbs such as thermocouples and resistance temperature detectors (16) are installed (
) so that the temperature of one lens 12b can be detected.

For example, when a thermistor is used as the temperature sensor 16, it is possible to connect the constant voltage source of the temperature detection processing section 17 in series with a reference resistor to extract a detection signal voltage whose resistance value changes depending on the temperature. (Of course, a Boyston bridge structure is also possible.) Further, when the temperature sensor 16 is formed of a thermocouple, the difference signal output from the compensation cold junction (constant temperature junction) of the temperature detection processing section 17 corresponds to the drought. Signal outputs corresponding to these temperatures are output from the temperature detection processing section 17, and are compared with a voltage Vs corresponding to a reference temperature when a predetermined focal length is set in advance by a comparator 18. A difference signal voltage is output as a comparison output. This comparison output corresponds to the amount of deviation from a predetermined temperature when the focal length is set in advance, and is input to the applied voltage control circuit 19.

The upper applied electric juice control circuit 19 is composed of a characteristic correction circuit 20 and a variable voltage output circuit 21, and the output of the variable voltage output circuit 21 is applied to the inner electrodes 13a and 13b. ing.

The single variable voltage output circuit 21 outputs A from the DC/AC converter 22 (or oscillator) according to the control voltage level applied to its control end (converts DC from DC power supply V to AC).
The voltage level (amplitude) of the C output is varied and outputted. Therefore, by outputting a predetermined voltage for a predetermined temperature and applying it to each liquid crystal 11a, 11b, the refractive index is controlled so that each lens portion 4.5 has a set focal length. In addition, the refractive index of each liquid crystal 11a and 11b changes due to a temperature change of each liquid crystal 11a and 11b, and the focal length changes according to a signal based on the detection signal level of the temperature sensor 16. An output voltage is applied to compensate (prevent) by controlling the alignment of liquid crystal molecules. For example, when a nematic liquid crystal PCB is used as the liquid crystals 11a and 11b, in the confusion region of room humidity, as the temperature increases, the refractive index decreases especially for temperature-dependent abnormal rays. The firing distance increases. This change in focal length due to temperature change can be prevented by reducing the applied voltage to increase the refractive index and prevent the focal length from changing due to temperature change. Since the humidity change mentioned above can usually change over several tens of degrees, the temperature change for that change area is J:
A characteristic correction circuit 20 is provided to accurately compensate for changes in focal length.

For example, when the focal length changes as shown by the broken line a in Figure 4 due to a change in the hot water level, in order to compensate for this change, the output signal of the comparator 18 is applied to the variable voltage output circuit 21 to variably control the output voltage. In this case, it is generally difficult to completely compensate for the temperature change using this control, as shown by the dashed line in the figure. In the first embodiment, by interposing a characteristic correction circuit 20 for correcting this deviation,
As shown by the solid line C in the figure, the influence of temperature change can be compensated for (M can be canceled).

When the first embodiment configured as described above is used in an environment where the ambient temperature changes, even if the refractive index of the liquid crystals 11a and 11b forming each lens portion 4.5 changes, the temperature will not change. The applied voltage is detected by the sensor 16, and the applied voltage control circuit 19 is controlled based on this detection signal, so that the applied voltage is automatically variably controlled so as to eliminate changes in focal length due to temperature changes.

Therefore, even when the diopter adjustment function of the person using the first embodiment is degraded, the person using the first embodiment can avoid being unable to focus due to temperature changes.

FIG. 5 shows a second embodiment of the invention. In this embodiment, a pair of focal length variable lenses 32a and 32b in each of the left and right lens sections 31 (only one is shown in the figure) are formed using plano-convex lenses 33a and 33b.

In other words, in the focal length variable lenses 12a and 12b shown in FIG.
t) is housed in a parallel plate, and a variable focal length lens 328, 32b is formed by liquid crystals 34a, 34b whose refractive index is variable and biconvex lenses 33a, 33b.

The other configurations are the same as the first embodiment between -1 and
The effects are almost the same.

According to this embodiment, even if the convex lens-shaped liquid crystals 11a and 11b in the first embodiment are not voltage dependent,
Even on a platform that exhibits electric field dependence of 1!1, the liquid crystal 34
Since the thickness of each part of a and 34b is made equal, there is an inconvenience and the thickness is 27 mm.

FIG. 6 shows a third embodiment.

This third embodiment is different from the first embodiment by allowing manual selection and setting of preset focal lengths. It is now configurable. The number that can be selected and set is not limited to the above three. ).

The above-mentioned focal length can be set by switching a switch SW, and by this switching, the applied voltage output from the variable voltage output circuit 21 at a predetermined temperature is set to be different.

Further, when the temperature changes, the characteristic correction in the characteristic correction circuit 20 can also be switched in conjunction with it so that the set focal length can be maintained.

This third embodiment is suitable for use by people who have had their crystalline lenses removed due to cataracts, for example, and does not require multiple glasses.
It has the advantage that only one piece is required. It is also suitable for use by people whose diopter adjustment function has deteriorated.

FIG. 7 shows a fourth embodiment of the invention. In this embodiment, in the lens portion 4 (or 5) of the first embodiment, a liquid crystal filling passage 35 communicating with each liquid crystal housing portion is provided in the frame 6 as shown in FIG. The liquid crystal is introduced into the filling passage 35 from the end thereof opening on the side surface of the frame 6, and then this end is closed, thereby making it possible to seal the liquid crystal into the cylinder.

Further, the temperature sensor 16 has 11 temperature detections near the enclosure path 35. In FIG. 7, the substantially circular broken line indicates the boundary when 14 liquid crystals are displayed.

The rest is the same as the first embodiment.

FIG. 8 shows a fifth embodiment of the invention.

This embodiment applies to the liquid crystal glasses 1 shown in FIG. 2, for example, on the front surface of the lens frame portion of the frame 6 (l--
Solar cells 4 such as Adolf 7 are attached to
The solar cell 41 uses the generated DC electromotive force to charge the DC power source V of the entire control unit 3. This charging is done by the electromotive force F If the voltage is larger than 1 iV, charging can be done through a diode to prevent backflow.Also, if the intensity of the incident light is weak, the power supply V
DC/AC that oscillates at low voltage when J is small:]
The voltage may be boosted by an inverter and then rectified. These may be switched manually, or it may be possible to detect whether the electromotive force F is greater than the voltage of the power supply V using an electromotive force [as a power source, and automatically switch based on the detection signal. You can also do it. Furthermore, if the control section can be driven by the electromotive force F, it may be automatically switched to the power source (2) so that it is directly driven.

The structures of the left and right lens parts according to the present invention are limited to those described above.
It may be of the structure shown in the figure.

Each lens on the left (-) in Figure 9 (only one shown) 5
1, the transparent plates 10d and 10b shown in FIG. 1 are concave transparent plates 52a and 52b, and the transparent plates 8 and 528. In addition, liquid crystals 53a and 53 are arranged in a concave lens shape between 8 and 52b.
F) may be enclosed with variable focal length lenses 54a and 54b which function as concave lenses.

Further, in FIG. 9, the liquid crystals 53a and 53b may be made into flat plate shapes, and the transparent plates 52a and 53b may be made into concave lens shapes.

In addition, to bring back the presence of the crystalline lens (lens) and to correct its focus, a plate-shaped lens is inserted between parallel plate-shaped transparent plates 8.55a, B, and 55b in Figure 10. LCD 56a,
56b may be enclosed -16=. Further, in each of the above-mentioned lens parts, it is also possible to form a Fresnel structure in which a sawtooth-like uneven part is provided on one electrode surface. For example, in the lens section shown in FIG. 10, a large number of sawtooth-shaped uneven portions are provided on the inner surface of each of the outer transparent plates 55a and 55b, and transparent electrodes are provided thereon (liquid crystal 56a, liquid crystal 56a, By forming a Fresnel structure in which unevenness is formed on the electrode surface in contact with one surface of each of the electrodes 56b, it is possible to improve the responsiveness of alignment of liquid crystal molecules to application of voltage.

In addition, for example, a plano-convex lens 33a shown in FIG.

The inside of the liquid crystal 34.33b is made concave. By making the a and 34b sides function as concave lenses, it is also possible to make a composite lens that functions as both a concave lens and a convex lens.

Also, it may be a combination of the above,
In addition, by overlapping the lenses, a variable focal length lens having both the functions of a convex lens and a concave lens can be realized.

Further, the Fresnel structure may be formed not only on one electrode surface but also on the other electrode surface.

Note that the control section 3 can also be structured so that it also serves as a part of the frame 6.

It is also possible to construct a variable focal length lens using a polarizer.

In addition, as shown in Fig. 10, electrodes are provided concentrically in the flat glasses part, and the voltage applied to the central part and the peripheral part is variably controlled to have slightly different values. Accordingly, it is possible to configure a variable focal length lens that functions as a convex lens or a concave lens, or has both functions.

Note that the configuration of the control section 3 is not limited to that shown in FIG. 1 or FIG. 6, and may have a different configuration. For example, the first
In the figure, a simplified version in which the output of the temperature detection processing section 17 is input directly to the applied voltage control circuit 19 also belongs to the present invention.

Note that the transparent plate, convex lens, etc. forming each lens portion are not limited to glass, and may be made of, for example, relatively hard plastic, elastic plastic, or a combination of these. Further, it can also be formed of a material that can cover the thermal expansion (thermal contraction) of the liquid crystal.

[Effects of the Invention] As described above, according to the present invention, a variable focus lens that can change the focal length according to the applied voltage using a liquid crystal, and changes in the focal length caused by temperature changes are Since the device is equipped with a means for temperature compensation by controlling the applied voltage based on the signal output of the detection means, even if the surrounding temperature changes, the focus will shift due to the temperature change, making it impossible to see clearly. It is possible to prevent +L from happening.

Also, one pair of glasses can cover multiple focal lengths, eliminating the need to carry multiple pairs of glasses all the time.
You can eliminate the hassle of changing J.

[Brief explanation of drawings]

FIGS. 1 to 4 relate to a first embodiment of the present invention.
The figure is a configuration diagram showing the configuration of the first embodiment, FIG. 2 is a perspective view showing the appearance of the first embodiment, and FIG. 3 is a plan view of the first embodiment.
FIG. 4 is a characteristic diagram for explaining the operation of the first embodiment, FIG. 5 is a configuration diagram showing the second embodiment of the present invention, and FIG. 6 is a characteristic diagram for explaining the operation of the first embodiment.
7 is a front view showing a part of the fourth embodiment of the present invention, FIG. 8 is a perspective view showing the fifth embodiment of the present invention, and FIG. 9 is a lens according to the present invention. FIG. 10 is a sectional view showing still another example of the structure of the lens portion according to the present invention. 1... Liquid crystal glasses 2... Glasses part 3... Control part 4, 5... Lens part 6... Room 8. 10a, 10b... Transparent plate 11a, llb... Liquid crystal

Claims (3)

[Claims] (1) In liquid crystal glasses using a liquid crystal whose refractive index changes as the alignment state of liquid crystal molecules changes when an external voltage is applied, a liquid crystal temperature detecting means and a detection signal from the temperature detecting means are used to detect the temperature of the liquid crystal. 1. Liquid crystal glasses, characterized in that the liquid crystal glasses are provided with applied voltage control means for variably controlling the applied voltage, thereby compensating for changes in the refractive index of the liquid crystal due to temperature changes by controlling the alignment of the liquid crystal. (2) The liquid crystal glasses according to claim 1, wherein the applied voltage control means includes a switching signal means that allows the focal length of the liquid crystal glasses to be set to a plurality of different values. (3) The liquid crystal glasses according to claim 1, further comprising a solar cell for charging the power source of the temperature detection means and the applied voltage control means.