JP2018045076A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a cross cylinder without requiring a mechanical mechanism for rotation or switching.SOLUTION: An optical device comprises: a pair of glass substrates 121 and 122 that is arranged with a gap; a transparent polar liquid 132 that is encapsulated between the pair of the glass substrates 121 and 122 and has a first refractive index; a transparent non-polar liquid 133 that is separated from the polar liquid 132, and has a second refractive index; an electrode that applies a voltage between the glass substrates 121 and 122; a control unit that controls an in-plane distribution between the glass substrates 121 and 122 of the voltage; and a lens that is formed by any of the polar liquid 132 or the non-polar liquid 133. The lens is configured to adjust the in-plane distribution to thereby have a first optical characteristic in a first radial direction, and a second optical characteristic in a second direction diameter different from the first radial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical device that can be used as a VCC (Variable cross cylinder).

  A CC (Cross cylinder) is known as an optical device used for astigmatism inspection (see, for example, Patent Document 1).

JP 05-176893 A

  In the inspection of astigmatism, it is necessary to rotate the cross cylinder. Normally, the rotation of the cross cylinder is mechanically performed manually or using a drive source such as a motor. There is also a method of preparing a plurality of cross cylinders and switching them. In any case, a high-precision movable part for machine control is required, the cost is high, and the entire apparatus is enlarged. In addition, since it is a precision machine, maintenance is required to maintain its performance. In addition, the manual method has problems such as the burden on the inspector and variations in accuracy due to skill, and is not common in the present age.

  In such a background, an object of the present invention is to provide a cross cylinder that does not require a mechanical mechanism for rotation and switching.

  The invention according to claim 1 is a pair of light-transmitting substrates disposed with a gap, a transparent polar liquid having a first refractive index sealed between the pair of substrates, and the A nonpolar liquid that is transparent from the polar liquid and has the second refractive index, an electrode that applies a voltage between the pair of substrates, and a controller that controls an in-plane distribution of the voltage between the pair of substrates And a lens formed of the polar liquid or the nonpolar liquid, and the lens has a first optical characteristic in a first radial direction by adjusting the in-plane distribution, An optical device having a second optical characteristic in a second radial direction different from the first radial direction.

  The invention described in claim 2 is the invention described in claim 1, characterized in that the electrode includes a plurality of electrodes arranged radially. According to a third aspect of the present invention, in the second aspect of the present invention, a cross cylinder is formed by a shape of an interface between the polar liquid and the nonpolar liquid.

  The invention according to claim 4 is the invention according to claim 3, wherein the cross cylinder is rotated by changing the in-plane distribution of the voltage between the pair of substrates. The invention described in claim 5 is characterized in that in the invention described in claim 3 or 4, astigmatism information of the eye to be examined is acquired from the control parameter of the cross cylinder.

  The invention according to claim 6 controls the in-plane distribution of the voltage between the pair of substrates based on astigmatism information of the eye to be examined in the invention according to any one of claims 1 to 5. The lens formed of the polar liquid or the nonpolar liquid is an astigmatism correcting lens that corrects astigmatism of the eye to be examined.

  According to the present invention, a cross cylinder that does not require a mechanical mechanism for rotation and switching can be obtained.

It is a principle figure which shows the principle of embodiment. It is a figure which shows the electrode structure of embodiment. It is a block diagram of a control system. It is an example of the lens implement | achieved by embodiment. It is an example of the lens implement | achieved by embodiment. It is an example of the ophthalmologic apparatus using invention.

(Constitution)
FIG. 1 shows a cross-sectional structure of a liquid optical device 100 using the invention. The liquid optical device 100 can be used as a VCC (Variable cross cylinder). In the present specification, the cross cylinder is a lens whose power of two meridians is ± 0.50D, and VCC (Variable cross cylinder) is a lens that can vary the power of two meridians. The shape of the liquid optical device 100 viewed from the direction of the optical axis has a substantially circular appearance. The liquid optical device 100 is configured by using a pair of glass substrates 121 and 122 arranged to face each other with a gap. The substrate may be other than glass as long as it is a material having visible light permeability. For example, a transparent plastic material can be used as the substrate.

  An active electrode layer 123 and a high dielectric film 124 are laminated on the lower glass substrate 121. FIG. 2 shows an outline of the active electrode layer 123 as viewed from the optical axis direction. The active electrode layer 123 has a central circular area as an active matrix electrode and areas other than the central area as radial electrodes. The active matrix electrode has a plurality of electrodes arranged in a lattice pattern. The radial electrode has a shape in which 72 longitudinal electrodes are arranged radially at intervals of 5 °. The number of divisions of the radial electrodes is not limited to the number illustrated in FIG. Increasing the number of divisions enables more accurate control, but the structure becomes complicated.

  The active matrix electrode and the radial electrode that constitute the active electrode layer 123 are configured by a transparent conductive film (ITO film). A thin film transistor to be determined is connected. This structure is the same as that of an active matrix liquid crystal display. Each of the electrodes constituting the active matrix electrode and the radial electrode can vary the level of the applied voltage in addition to the presence or absence of voltage application. The change in the level of the applied voltage may be continuous or may be a plurality of stepped steps.

  Returning to FIG. 1, as the high dielectric film 124, for example, PVdF (polyvinylidene fluoride) or PTFE (polytetrafluoroethylene) is used. A water repellent film 125 is disposed in contact with the high dielectric film 124. The water repellent film 125 is a film having water repellency, and for example, Teflon AF (registered trademark) or Cytop is used.

  A ring member 126 is disposed in contact with the water repellent film 125. The ring member 126 is a ring-shaped member and is in contact with the water repellent film 125 and the high dielectric film 127, and an internal space 128 is formed inside thereof. The upper high dielectric film 127 is in contact with the upper transparent conductive film (ITO film) 129, and the transparent conductive film 129 is in contact with the upper glass substrate 122. The transparent conductive film 129 is uniformly provided on the entire surface of the region that effectively functions as an optical member. The periphery of the ring member 126 is sealed with a sealing material 130, and the internal space 128 is a sealed space.

  On the side of the internal space 128 of the high dielectric film 127, a hydrophilic film 131 is disposed. The hydrophilic film 131 is a film having a hydrophilic function, and is made of an inorganic dispersion such as trisilanol or silica. The internal space 128 is filled with a transparent aqueous polar liquid 132 and a transparent nonpolar liquid 133. Specific examples of the polar liquid 132 include water and methanol. Examples of the nonpolar liquid 133 include oils such as hydrocarbon-based synthetic oils and silicone oils. The polar liquid 132 and the nonpolar liquid 133 are transparent, have a difference in refractive index, and have a property of separating without being mixed with each other like water and oil. In this example, the refractive index of the nonpolar liquid 133 is set so as to be higher than the refractive power of the polar component liquid 132, and the lens is configured by the portion of the nonpolar liquid 133. Of course, the lens may be configured by the portion of the polar liquid 132 by setting the refractive index of the nonpolar liquid 133 to be smaller than the refractive power of the polar component liquid 132.

  The size of each part is an example, but the effective surface of the liquid optical device 100 (the region that functions effectively as a lens) is a circle having a diameter of about 25 mm to 40 mm, and the thickness of the glass substrates 121 and 122 is 0.1 to 0.1 mm. The thickness of the high dielectric film 124 is 0.5 to 5 μm, the thickness of the water repellent film 125 is several to 500 nm, and the height of the internal space (the distance between the water repellent film 125 and the hydrophilic film 131) is 0. 0.1 to 5 mm, the thickness of the high dielectric film 127 is 0.3 to 5 μm, the thickness of the hydrophilic film 131 is several to 500 μm, and the thickness of the transparent conductive film 129 is 10 to 200 nm. Examples of the dimensions of each part of the active electrode layer 123 include values adopted in known active matrix substrates for liquid crystal displays.

  The nonpolar liquid 133 portion constitutes a lens. The shape of the lens composed of the nonpolar liquid 133 can be controlled. For example, when a relatively high voltage is applied on the outer peripheral side of the active electrode layer 123 and a relatively low voltage is applied near the center, the lens formed of the nonpolar liquid 133 has a cross-sectional shape shown in FIG. It becomes a convex lens. This is obtained as a result of the nonpolar liquid 133 concentrating near the center because the polar liquid 132 concentrates on the outer peripheral side where the electric field density is large.

  On the other hand, when a low voltage is applied on the outer peripheral side of the active electrode layer 123 and a high voltage is applied near the center, the lens composed of the nonpolar liquid 133 becomes a concave lens having a cross-sectional shape shown in FIG. This is obtained as a result of the polar liquid 132 concentrating on the center side where the electric field density is large, so that the nonpolar liquid 133 is thin near the center and thick at the outer periphery.

  The electrodes constituting the active electrode layer 123 shown in FIG. 2 can individually adjust the voltage application level. Here, the voltage application profile in the cross section along the X-axis direction in FIG. 2 has the form shown in FIG. 1A, and the voltage application profile in the cross section along the Y-axis in FIG. If the shape is different from 1 (A), lenses having different shapes can be obtained in the cross section along the X axis and the cross section along the Y axis. Further, the center position of the convex lens and the concave lens can be decentered from the center by adjusting the applied voltage distribution. In addition, a lens having a cross-sectional shape with broken symmetry can be realized.

  Further, in the above embodiment, by adjusting the voltage gradient in the Y-axis direction, the cross section along the X axis is the convex lens in FIG. 1A, and the cross section along the Y axis functions as a lens. A cylindrical lens that does not work can be obtained. An example of this cylindrical lens is shown in FIG.

  The function of the cross cylinder can be realized by the above principle. In this configuration, a mechanical movable part is not required for the reversal or rotation of the cross cylinder, and the reversal or rotation of the cross cylinder is performed by electric control by a drive signal supplied to the active electrode layer 123.

  In the simplest control, the axial angle pitch (rotational angle pitch) of the cross cylinder in FIG. 2 is 5 ° (since the radial electrodes are 5 ° pitch). In the active electrode layer 123 shown in FIG. 2, the rotation angle of the cross cylinder can be adjusted in steps smaller than 5 °. However, in this case, the potential of the radial electrode needs to be varied in multiple steps or continuously.

  FIG. 4A shows an example of lenses having different spherical powers in two axes orthogonal to the optical axis (two radial directions intersecting at 90 °). FIG. 4B shows an example in which a cylindrical lens (cylindrical lens) is realized. The lenses shown in FIGS. 4A and 4B can be realized by adjusting the potential of each electrode of the active electrode layer 123. 4 shows a state in which the lens is cut into a rectangle so that the cross section can be easily understood, but the shape of the lens when the liquid optical device 100 is actually viewed from the direction of the optical axis is circular. Depending on how the voltage is applied, an elliptical or distorted circular lens is also possible.

  Two optical devices having the configuration of the liquid optical device 100 of FIG. 1 can be prepared and used by overlapping them on the optical axis. In this case, a lens in which the concave cylindrical lens and the convex cylindrical lens shown in FIG. 5 are arranged orthogonally can be obtained. The lens of FIG. 5 can be applied to a lens for correcting astigmatism.

(Control system)
A control system of the liquid optical device 100 will be described. FIG. 3 shows a control device 200 that controls the liquid optical device 100. The control device 200 functions as a computer and includes a CPU, a memory, and various interfaces. The arithmetic unit 200 is configured using a general-purpose microcomputer, but a part or all of the arithmetic unit 200 may be configured with a dedicated electronic circuit.

  The control device 200 includes a parameter input unit 201, a calculation unit 202, and a control signal generation unit 203. The parameter input unit 201 receives information on the S value, C value, and A value of the eye to be examined. Here, the S value is a spherical power (−myopia, + farsightedness), and is a refractive power of a concave lens / convex lens used for correction of myopia or hyperopia. The C value is an astigmatism power, and is a refractive power of a cylindrical lens used for astigmatism correction. The A value is obtained by quantifying the angle at which the cylindrical lens for astigmatism enters between 1 ° and 180 °. The C value and the A value are parameters that define the state of astigmatism and are examples of astigmatism information.

(First example)
By specifying the S value, the C value, and the A value, a VCC (Variable Cross Cylinder) using the liquid optical device 100 is obtained. The VCC using the liquid optical device 100 can electrically rotate the cross cylinder around the optical axis by electrical control. In the case of FIG. 2, the cross cylinder can be rotated in 5 ° steps. This rotation is controlled by a control signal supplied to the liquid optical device 100. At this time, only the polar liquid 132 and the nonpolar liquid 133 that moves passively according to the movement of the polar liquid 132 physically move, and there is no place where the mechanical parts move.

  Since the liquid optical device 100 can easily change one or more values of the S value, the C value, and the A value, the S value, the C value, and the electronic value can be changed electronically without replacing the physical lens. A lens in which one or more values of the A value are changed can be realized by changing the shape of the nonpolar liquid 133. Therefore, by using the liquid optical device 100, cross-cylinder optometry (inspection for astigmatism) can be performed more efficiently. That is, in the cross-cylinder type optometry, an operation of reversing and rotating the cross cylinder is necessary, but in the liquid optical device 100, this operation is performed by electrical control. Moreover, the change of the constant (change of one or more values of the S value, the C value, and the A value) can be easily performed by operating a switch or the like.

(Second example)
When the S value, C value, and A value of the eye to be examined are known, the liquid optical device 100 can be used to create a lens that can correct the myopia, hyperopia, and astigmatism of the eye to be examined. In this example, the S value, C value, and A value input to the parameter input unit 201 are sent to the calculation unit 202. Based on the input S value, C value, and A value, the calculation unit 202 calculates a lens shape that can correct these values to a prescribed value. The relationship between the S value, the C value, and the A value and the desired lens shape is examined in advance, and the data is stored in the memory of the control device 200. Based on this data, the calculation unit 202 calculates the shape of the lens.

  Further, the relationship between the shape of the lens and the voltage applied to each electrode in the liquid optical device 100 is also examined in advance, and the data is stored in the memory of the control device 200. Based on this data, the control signal generation unit 203 generates a control signal to be sent to the liquid optical device 100, and forms the lens having the shape calculated by the calculation unit 202 with the liquid optical device 100.

  According to this technique, a correction lens suitable for the subject eye can be created by the liquid optical device 100 by electrical processing based on the S value, C value, and A value of the subject eye. Further, since fine adjustment in the optical axis direction of the lens is possible, it is possible to obtain a lens in which optical characteristics that cannot be pursued by the S value, C value, and A value are adjusted according to the eye to be examined.

(Third example)
FIG. 6 shows an optometry apparatus 400. The optometry apparatus 400 has a function of performing astigmatism optometry (of course, other optometry functions may be provided). The optometry apparatus 400 includes a liquid optical device 100A and a liquid optical device 100B having the same structure and function as the liquid optical device 100 of FIG. Each of the liquid optical device 100A and the liquid optical device 100B is individually controlled by the control device 200 shown in FIG.

  The optometry apparatus 400 includes a parameter calculation unit 300. The parameter calculation unit 300 calculates the C value and A value of the eye to be examined. The C value is the power of astigmatism, and is the refractive power of the cylindrical lens used for astigmatism correction. The A value is an angle at which the cylindrical lens for astigmatism enters. The optometry apparatus 400 also has a function of inspecting the S value (spherical power (−myopia, + farsightedness)), but since this is the same as the existing optometry apparatus, description thereof is omitted.

  The inspection of the C value and the A value is performed as follows. The liquid optical devices 100A and 100B have a function of a cross cylinder that can change the setting of the angular position and the frequency. By utilizing this function, optometry using a cross cylinder target is performed to obtain the C value and the A value. The method for obtaining the C value and the A value is the same as in the known cross cylinder test. In the cross cylinder, the left and right are not inspected at the same time, and the cross cylinder target is displayed for each eye and inspected.

  That is, the power of the cylindrical lens realized there can be calculated from the control parameters of the liquid optical devices 100A and 100B when the optimal cylindrical lens is selected in the cross cylinder test. This is the calculation principle of the C value (astigmatism power: refractive power of a cylindrical lens used for astigmatism correction). Further, in the above state, the angle with respect to the reference direction (for example, the vertical direction) of the cylindrical lens realized there can be calculated from the control parameters of the liquid optical devices 100A and 100B. Thereby, the A value is obtained. In this way, the parameter calculation unit 300 calculates the C value and the A value for each of the left and right eyes.

  After calculating the C value and the A value, together with the separately acquired S value, these data are input to the control device 200, and the correction lens suitable for the eye to be examined is applied to the liquid optical devices 100A and 100B by the control described in relation to FIG. To achieve.

  A specific example will be described below. For example, as a result of the above-described cross cylinder test, it is assumed that the S value is +1.00 degrees, the C value is +1.00 degrees, and the A value is 180 degrees for the eye to be examined. In this case, the active electrode layer 123 is electronically controlled to adjust the potential of each electrode so that the lens shape corresponds to S value: +1.00 degrees, C value: +1.00 degrees, and A value: 180 degrees. To do. As a result, the shape of the nonpolar liquid 133 differs in the orthogonal radial direction (see, for example, FIG. 4), and a lens for correcting astigmatism corresponding to the S value, C value, and A value is obtained.

(Musubi)
As described above, the liquid optical device 100 shown in FIG. 1 includes a pair of glass substrates 121 and 122 arranged with a gap and a transparent first sealed between the pair of glass substrates 121 and 122. A polar liquid 132 having a refractive index and a nonpolar liquid 133 that is separated from the polar liquid 132 and having a second refractive index, an electrode for applying a voltage between the glass substrates 121 and 122, and a glass having the voltage A control unit 200 (see FIG. 3) that controls the in-plane distribution between the substrates 121 and 122 and a lens formed by the polar liquid 132 or the nonpolar liquid 133, the lens adjusting the in-plane distribution. Thus, the first optical characteristic as shown in FIG. 4 is provided in the first radial direction, and the second optical characteristic is shown in the second radial direction different from the first radial direction. .

  With this configuration, a cross cylinder that does not require a mechanical mechanism for rotation and switching can be obtained. In addition, since the lens shape can be electrically changed, a lens for correcting astigmatism can be obtained based on astigmatism information such as C value and A value.

  DESCRIPTION OF SYMBOLS 100 ... Liquid optical apparatus, 100A ... VCC for left eyes, 100B ... Liquid optical apparatus for right eyes, 121 ... Glass substrate, 122 ... Glass substrate, 123 ... Active electrode layer, 124 ... High dielectric film, 125 ... Water repellent Membrane, 126 ... Ring member, 127 ... High dielectric film, 128 ... Inner space, 129 ... Transparent conductive film, 130 ... Sealing material, 131 ... Hydrophilic film, 132 ... Polarized liquid, 133 ... Nonpolar liquid, 400 Ophthalmic apparatus .

Claims (6)

A pair of light-transmitting substrates arranged with a gap;
A transparent polar liquid having a first refractive index sealed between the pair of substrates and a nonpolar liquid having a second refractive index which is transparent and separated from the polar liquid;
An electrode for applying a voltage between the pair of substrates;
A controller that controls in-plane distribution of the voltage between the pair of substrates;
A lens formed of the polar liquid or the nonpolar liquid,
The lens has a first optical characteristic in a first radial direction by adjusting the in-plane distribution, and a second optical characteristic in a second radial direction different from the first radial direction. An optical device.   The optical apparatus according to claim 1, wherein the electrodes include a plurality of electrodes arranged radially.   The optical apparatus according to claim 2, wherein a cross cylinder is configured by a shape of an interface between the polar liquid and the nonpolar liquid.   The optical apparatus according to claim 3, wherein the cross cylinder is rotated by changing the in-plane distribution of the voltage between the pair of substrates.   The optical device according to claim 3, wherein astigmatism information of the eye to be examined is acquired from a control parameter of the cross cylinder. By controlling the in-plane distribution of the voltage between the pair of substrates based on astigmatism information of the eye to be examined, a lens formed of the polar liquid or the nonpolar liquid is corrected for astigmatism of the eye to be examined. The optical device according to claim 1, wherein the optical device is an astigmatism correcting lens.

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