CN110286502B - Presbyopia vision correction device - Google Patents

Abstract

The invention relates to the field of optics technology, and discloses a vision correction device for presbyopia, so as to optimize the use experience of users and realize convenience and light weight. The device of the present invention comprises: a linear polarizer, a first flat lens based on an electronically controlled birefringent material, and a 1/4 wave plate located between the linear polarizer and the first flat lens; A voltage control system for a flat lens, so that the first flat lens: in the case of no electric field when the circuit corresponding to the voltage control system is disconnected, realizing a non-zero diffracted light beam of the same order is equivalent to converging the light beam with a real focus by a convex lens; In the case of the saturated electric field corresponding to the closed circuit of the voltage control system, the function equivalent to the flat window is realized.

Description

Presbyopia vision correction device

technical field

The invention relates to the field of optical technology, in particular to a vision correction device for presbyopia.

Background technique

The core principle of the vision correction device is to diversify or focus the ambient light incident on the human eye to a certain extent through the optical system, so that the imaging beam can finally be focused on the retina of the human eye. Existing vision correction technical solutions generally use traditional curved concave/convex lenses to achieve beam divergence/focusing. The defects are: 1. The thickness of the lens is large and bulky, especially for high myopia above 1000 degrees, the thickness of the edge of the lens can often be reduced. Reach about 10mm; 2. The curved lens is not an ideal optical system and cannot form a perfect image, and there will inevitably be aberrations, which will make the scene perceived by the human eye deviate from the actual.

It is worth noting that presbyopia is the same as hyperopia, both of which are difficult to see near things, and need to wear a convex lens to help correct it. But there are essential differences between the two. Hyperopia is a refractive error, which is a pathological phenomenon, while presbyopia is a natural physiological phenomenon of human aging. Hyperopia's nearsightedness and farsightedness have defects, especially for severe farsightedness that exceeds the eye's ability to accommodate, it is necessary to wear glasses to correct nearsightedness and farsightedness at the same time. Presbyopia cannot see near clearly, but it is normal to see far. Wearing glasses is mainly to correct nearsightedness. You don’t need to wear glasses when you see far. You need to take off and wear glasses back and forth in daily life. In reality, there are also patients with double vision defects who suffer from both myopia and presbyopia, and cannot see both distant and near scenes clearly. If equipped with two glasses of nearsightedness and farsightedness, it is very inconvenient to carry and switch back and forth; ordinary positive and negative bifocal glasses that integrate farsightedness and nearsightedness correction functions have serious visual field defects, and the present invention aims to solve the above problems.

SUMMARY OF THE INVENTION

The purpose of the present invention is to disclose a vision correction device for presbyopia, so as to optimize the user's use experience and realize convenience and light weight.

In order to achieve the above purpose, the present invention discloses a vision correction device for presbyopia, comprising:

a linear polarizer, a first plate lens based on an electronically controlled birefringent material, and a quarter wave plate between the linear polarizer and the first plate lens; and

A voltage control system for switching the flat lens so that the first flat lens:

In the case of no electric field corresponding to the disconnection of the voltage control system circuit, realizing a non-zero same-order diffracted light beam is equivalent to converging the light beam with a real focus by a convex lens;

In the case of a saturated electric field corresponding to the closed circuit of the voltage control system, a function equivalent to a flat window is realized.

Further, the present invention also includes a second flat lens arranged adjacent to the first flat lens, and the rotation directions of the fast axis of the second flat lens and the first flat lens are opposite to each other in the absence of an electric field , so that: when the first flat lens and the second flat lens are replaced in the absence of an electric field, when the incident light of the same polarization state converges after passing through the first flat lens, the incident light of the polarization state passes through the When the incident light of the same polarization state diverges after the second plate lens, or the incident light of the same polarization state diverges after passing through the first plate lens, the incident light of the polarization state converges after passing through the second plate lens; the voltage control system also uses when a saturation voltage is applied to the first flat lens, the second flat lens is kept in an electric field-free condition; and when a saturation voltage is applied to the second flat lens, the first flat lens is kept in an electric field-free condition Happening. In this way, the problems of myopia and presbyopia existing in the user at the same time can be solved.

Alternatively, the birefringent material of the present invention may be made of liquid crystals or liquid crystal polymers.

The present invention has the following beneficial effects:

By switching the on-off state of the first flat lens, the presbyopic user can switch between the far and near vision without taking off the glasses, which can effectively improve the service life of the glasses while improving the user experience. At the same time, the structure of the present invention also has the function of making the final product lighter and thinner, so that the product based on the solution of the present invention also has an ultra-thin aesthetic effect.

Further, the present invention can use a flat lens whose fast axis orientation of birefringent material continuously changes ring by ring to realize the divergence or convergence of incident light, and realize the vision correction function equivalent to a concave lens or a convex lens; The phase is modulated to achieve aberration-free imaging while effectively avoiding the dependence on the thickness of the lens, so that the product of the present invention has a wide range of vision adjustment.

The present invention will be described in further detail below with reference to the accompanying drawings.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 is a functional schematic diagram of realizing a convex lens with a flat lens disclosed in an embodiment of the present invention;

2 is a schematic diagram of a model of a flat lens disclosed in an embodiment of the present invention based on a change in the direction of the fast axis;

3 is a schematic diagram of periodic changes in the direction of the fast axis based on the radial direction of the flat lens disclosed in the embodiment of the present invention;

4 is a functional schematic diagram of realizing a concave lens with a flat lens disclosed in an embodiment of the present invention;

5 is a schematic diagram of a component arrangement and an application scenario of presbyopia based on close-up measurement disclosed in an embodiment of the present invention;

6 is a schematic diagram of a component arrangement and an application scenario of presbyopia based on distant view detection disclosed in an embodiment of the present invention;

FIG. 7 is a schematic diagram of a component arrangement and an application scenario of a presbyopia combined myopic user based on distance measurement according to an embodiment of the present invention.

Detailed ways

The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

Example 1

This embodiment discloses a vision correction device for presbyopia, comprising: a linear polarizer, a first flat lens based on an electronically controlled birefringent material, a quarter wave plate located between the linear polarizer and the first flat lens, and a A voltage control system for switching flat lenses. Optionally, the birefringent material in this embodiment is made of liquid crystal or liquid crystal polymer.

In this embodiment, the voltage control system is specifically used to control the switching state of the first flat lens, so that the first flat lens can achieve a non-zero electric field when the circuit corresponding to the voltage control system is disconnected without an electric field, as shown in FIG. 1 . A diffracted beam of the same order is equivalent to a convex lens converging the beam with a real focus. On the other hand, if the first flat lens is under the condition of the saturated electric field corresponding to the closed circuit of the voltage control system, the function equivalent to the flat window is realized.

Optionally, as shown in FIG. 2 , the first flat lens in this embodiment is a ring-shaped symmetrical structure with the optical axis of the lens as the center. And in the case of no electric field, the first flat lens controls the periodic change of the fast axis direction of the birefringent material corresponding to each ring from 0 to 180 degrees, and the fast axis direction of the birefringent material on the same ring is consistent, so that The incident light is subjected to geometric phase modulation based on the change of polarization state to realize beam diffraction and deflection.

As shown in Figure 2 and Figure 3, the direction of the fast axis of the birefringent material between the adjacent rings of the first flat lens changes continuously, and the direction of the fast axis changes from 0 to 180 degrees as a change period, and the change speed is positive with the radius. Correlation, so that the diffraction angle corresponding to the same diffraction order of each ring increases with the increase of the radius of the ring, thereby realizing that the non-zero diffraction beam of the same order is equivalent to the convex lens converging the beam with a real focus.

Preferably, the first flat lens in this embodiment is also used for: deflecting the incident left-handed circularly polarized light into outgoing right-handed circularly polarized light, and/or deflecting the incident right-handed circularly polarized light into outgoing left-handed circularly polarized light . Specifically, for example, the first flat lens can be used for:

If the incident left-handed circularly polarized light can be deflected into right-handed circularly polarized light corresponding to the -1 diffraction order output, the incident right-handed circularly polarized light can also be deflected into left-handed circularly polarized light corresponding to the +1 diffraction order output; or

If the incident left-handed circularly polarized light can be deflected into a right-handed circularly polarized light corresponding to the +1 diffraction order, the incident right-handed circularly polarized light can also be deflected into a left-handed circularly polarized light corresponding to the -1 diffraction order.

Further, in the case of no electric field, referring to the corresponding relationship between FIG. 1 and FIG. 4 , the first flat lens is also used for:

If the incident left-handed circularly polarized light is deflected into a right-handed circularly polarized light corresponding to the -1 diffraction order, which is equivalent to the convex lens converging the beam with a real focus, the incident right-handed circularly polarized light can also be deflected into a corresponding + The left-handed circularly polarized light emitted from the 1st diffraction order is equivalent to a concave lens and diverges the light beam with a virtual focus.

Or, in the case of no electric field, referring to the corresponding relationship between FIG. 1 and FIG. 4 , the first flat lens is also used for:

If the incident right-handed circularly polarized light is deflected into a left-handed circularly polarized light corresponding to the -1 diffraction order, which is equivalent to the convex lens converging the beam with a real focus, the incident left-handed circularly polarized light can also be deflected into a corresponding +1 The right-handed circularly polarized light emitted from the diffracted order is equivalent to a concave lens and diverges the light beam with a virtual focus.

Different from the case of no electric field, in the case of a saturated electric field in the first flat lens of this embodiment, the long axis direction of the birefringent material corresponding to each ring is controlled to be parallel and aligned with the direction of the applied electric field, so that the flat lens changes. For ordinary parallel windows.

In addition, in the actual product deployment process, the lens adjacent to the user's eyes can be a flat lens or a linear polarizer. Most of the light entering the retina is the same for both deployments. The difference is that if the light entering the retina first passes through the linear polarizer, it is equivalent to filtering out part of the light by the linear polarizer first, turning it into linearly polarized light, and then converting the linearly deflected light into a 1/4 wave plate. (Left or right) circularly polarized light, and the final output from the flat lens is also (right or left) circularly polarized light. If the light entering the retina is first incident from the flat lens and then exits from the linear polarizer, the light emitted by the external natural light through the flat lens includes both left-handed circularly polarized light and right-handed circularly polarized light, and the two The diffraction angles are opposite. The specific situation can be one of the following types of settings:

Type 1. When the beam is incident from the end face of the polarizer, the angle between the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate is 45°, so that the polarization state of the outgoing beam from the wave plate is left-handed circularly polarized light.

Type 2. When the beam is incident from the end face of the polarizer, the angle between the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate is -45°, so that the polarization state of the outgoing beam from the wave plate is right-handed circularly polarized light.

Type 3. When the beam is incident from the end face of the flat lens, the angle between the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate is +45°, so that the outgoing beam of the linear polarizer is the same as the fast axis of the 1/4 wave plate. Linearly polarized light with an included angle of +45°.

Type 4. When the beam is incident from the end face of the flat lens, the angle between the polarization direction of the linear polarizer and the fast axis of the 1/4 wave plate is -45°, so that the outgoing beam of the linear polarizer is the same as the fast axis of the 1/4 wave plate. Linearly polarized light at an angle of -45°.

For details, please refer to the following actual usage scenarios:

As shown in Fig. 5, the presbyopia correction device of Example 1 is composed of linear polarizer 1, 1/4 wave plate 2 and first flat lens 3 in sequence along the z direction, and the three are attached together to form a coaxial optical system. Among them, the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate are -45 ゜, and the fast axis of the 1/4 wave plate is on the x-axis. On the first flat lens, a voltage control system 4 is also provided, which can choose not to pressurize or pressurize the flat lens through on and off operations.

When the human eye observes a nearby object, the incident natural light from the outside has a larger opening angle to the human eye and is in a divergent state. The natural light becomes linearly polarized light after passing through the linear polarizer, and the angle between the polarization direction and the fast axis of the 1/4 wave plate is -45゜. The light emitted from the 1/4 wave plate is right-handed circularly polarized light. At this time, the switch of the voltage control system is in an off state, and the first flat lens plays a converging role. The right-handed circularly polarized light is incident on the first flat lens based on the geometric phase. After the convergence of the right-handed circularly polarized light by the first flat lens, the divergence angle of the outgoing light becomes smaller, similar to the distant object beam. The human eye can be clearly imaged on the retina of the human eye, thereby correcting the defect of presbyopia.

When presbyopia patients need to observe distant objects, they can freely choose to switch the device of this embodiment to a non-presbyopia correction state. As shown in Figure 6, when the human eye observes a distant object, the external incident natural light has a small opening angle to the human eye. At this time, you can choose to close the switch, and the voltage control system starts to apply a saturation voltage to the first flat lens. Under the action of the saturation voltage, all the liquid crystal polymer molecules in the flat lens are aligned in one direction, and have no converging effect on the incident right-handed circularly polarized light, which is equivalent to a flat glass lens. clear image.

Embodiment 2

In this embodiment, on the basis of the above-mentioned first embodiment, the following product improvements are made for users who have both presbyopia and myopia. The specific improvement includes: adding a second flat lens adjacent to the first flat lens in the above-mentioned device, and the rotation directions of the fast axis of the second flat lens and the first flat lens are opposite to each other when there is no electric field.

In this way, when the first flat lens and the second flat lens are replaced without an electric field, when the incident light of the same polarization state passes through the first flat lens and converges, the incident light of the polarization state passes through the second flat lens. After the lens is divergent, or the incident light of the same polarization state is divergent after passing through the first flat lens, the incident light of the polarization state is converged after passing through the second flat lens.

Preferably, as a matching improvement, the voltage control system of this embodiment keeps the second flat lens in a state of no electric field when applying a saturation voltage to the first flat lens; and when applying a saturation voltage to the second flat lens, keeps the first flat lens The flat lens is in an electric field free condition. As a simple alternative, those skilled in the art can think of using two sets of voltage control systems to control the first and second flat lenses respectively, and such deformations belong to the protection scope of the present invention.

Based on the specific application scenario of this embodiment, reference may be made to FIG. 7 .

As shown in FIG. 7 , the vision correction device of this embodiment is composed of a linear polarizer 1, a 1/4 wave plate 2, a first flat lens 3, and a second flat lens 5 in turn along the z direction, and the four are attached together. Form a coaxial optical system. Among them, the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate are -45 ゜, and the fast axis of the 1/4 wave plate is on the x-axis. Wherein, the second plate lens diverges the right-handed circularly polarized light, and the first plate lens converges the right-handed circularly polarized light. On the two flat lenses, a voltage control system is also connected, and one of the flat lenses can be selected to be pressurized while the other flat lens is not pressurized through on and off operations. Specifically include:

When a patient with presbyopia and myopia and double vision defect observes a near scene (not the state shown in Figure 7), it is necessary to correct the presbyopia. At this time, the selector switch only needs to be switched to the second flat lens that diverges for right-handed circularly polarized light. The electronic control system starts to apply the saturation voltage to the second flat lens. Under the action of the saturation voltage, all the liquid crystal polymer molecules in the second flat lens are aligned in one direction and have no divergence effect on the incident right-handed circularly polarized light, which is equivalent to a flat glass lens. The first flat lens has no effect on the incident right-handed circularly polarized light Polarized light converges, thereby correcting presbyopic vision defects.

When a patient with double vision defect observes a distant scene, the myopia needs to be corrected (as shown in Figure 7). At this time, the selector switch only needs to be switched to the first flat lens that converges the right-handed circularly polarized light, and the voltage control system Start applying the saturation voltage to the first flat lens. Under the action of the saturation voltage, all the liquid crystal polymer molecules in the first flat lens are aligned in one direction and have no converging effect on the incident right-handed circularly polarized light, which is equivalent to a flat glass lens. Divergence of polarized light, thereby correcting short-sighted vision defects.

Embodiment 3

Further, on the basis of the above-mentioned first and second embodiments, this embodiment makes intelligent improvements based on user experience. Specifically, it includes: setting a working mode sensor in the voltage control system to detect whether the user's head is a head-down action for observing a close-up view, or a head-up or looking-up action based on a long-range view; Adaptive electric field state switching. Optionally, the working mode sensor includes but is not limited to a level sensor or other sensors based on visual changes of the user's eyes.

Optionally, the voltage control system of this embodiment is further provided with a matching switch for the user to turn on or off the adaptive electric field switching based on the working mode sensor. Usually, this switch can both turn off the automatic switching function to avoid misjudgment, and also allow us to manually switch between the first and second flat lenses. In other words, the matching switch can be manual touch, remote control, or even voiceprint control. Similarly, in the above two embodiments, the on-off state control of the first flat lens and the second flat lens by the electric field control system can also be based on the same design.

To sum up, the presbyopia vision correction device disclosed by the above embodiments of the present invention has the following beneficial effects: by switching the switch state of the first flat lens, the presbyopia user can switch between the far and near vision without taking off the glasses, While improving the user experience, it can also effectively improve the service life of the glasses. At the same time, the structure of the present invention also has the function of making the final product lighter and thinner, so that the product based on the solution of the present invention also has an ultra-thin aesthetic effect.

In addition, the present invention is based on the filtering effect of the linear polarizer on light, which partially weakens the light intensity of retinal imaging, so that it is more suitable for use under strong light, and naturally integrates the function of sunglasses.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (12)

1. a presbyopia vision correction device, is characterized in that, comprises: a linear polarizer, a first plate lens based on an electronically controlled birefringent material, and a quarter wave plate between the linear polarizer and the first plate lens; and A voltage control system for switching the flat lens so that the first flat lens: In the case of no electric field corresponding to the disconnection of the voltage control system circuit, realizing a non-zero same-order diffracted light beam is equivalent to converging the light beam with a real focus by a convex lens; In the case of a saturated electric field corresponding to the closed circuit of the voltage control system, a function equivalent to a flat window is realized; Wherein, the first flat lens has a ring-shaped symmetrical structure with the optical axis of the lens as the center, and is specifically used for: in the case of no electric field, respectively controlling the period of the fast axis direction of the birefringent material corresponding to each ring from 0 to 180 degrees To achieve the beam diffraction and deflection, the geometric phase modulation based on the polarization state change of the incident light is performed; Wherein, the direction of the fast axis of the birefringent material on the same ring of the first flat lens is consistent, the direction of the fast axis of the birefringent material between adjacent rings changes continuously, and the direction of the fast axis changes from 0 to 180 degrees as a change period, And the change speed is positively related to the radius, so that the diffraction angle corresponding to the same diffraction order of each ring increases with the increase of the ring radius, so that the non-zero diffraction beam of the same order is equivalent to the convex lens converging the beam with a real focus. 2. The vision correction device for presbyopia according to claim 1, wherein the first flat lens is specifically used for: controlling the long-axis direction of the birefringent material corresponding to each ring and the applied electric field in the case of a saturated electric field The directions are parallel and aligned so that the flat lenses are transformed into ordinary parallel windows. 3. presbyopia vision correction device according to claim 1, is characterized in that, described first flat lens is also used for: the left-handed circularly polarized light of incident is deflected into the right-handed circularly polarized light of exit, and/or the incident The right-handed circularly polarized light is deflected into outgoing left-handed circularly polarized light. 4. The vision correction device for presbyopia according to claim 3, wherein the first flat lens is also used for: If the incident left-handed circularly polarized light can be deflected into right-handed circularly polarized light corresponding to the -1 diffraction order output, the incident right-handed circularly polarized light can also be deflected into left-handed circularly polarized light corresponding to the +1 diffraction order output; or If the incident left-handed circularly polarized light can be deflected into a right-handed circularly polarized light corresponding to the +1 diffraction order, the incident right-handed circularly polarized light can also be deflected into a left-handed circularly polarized light corresponding to the -1 diffraction order. 5. The vision correction device for presbyopia according to claim 4, wherein, in the absence of an electric field, the first flat lens is also used for: If the incident left-handed circularly polarized light is deflected into a right-handed circularly polarized light corresponding to the -1 diffraction order, which is equivalent to the convex lens converging the beam with a real focus, the incident right-handed circularly polarized light can also be deflected into a corresponding + The left-handed circularly polarized light emitted from the 1st diffraction order is equivalent to a concave lens that diverges the beam with a virtual focus; or If the incident right-handed circularly polarized light is deflected into a left-handed circularly polarized light corresponding to the -1 diffraction order, which is equivalent to the convex lens converging the beam with a real focus, the incident left-handed circularly polarized light can also be deflected into a corresponding +1 The right-handed circularly polarized light emitted from the diffracted order is equivalent to a concave lens and diverges the light beam with a virtual focus. 6 . The vision correction device for presbyopia according to claim 5 , further comprising a second flat lens arranged adjacent to the first flat lens, and the second flat lens and the first flat lens are 6. 6 . In the absence of an electric field, the rotation directions of the fast axes are opposite to each other, so that when the first plate lens and the second plate lens are replaced in the absence of an electric field, the incident light of the same polarization state passes through the first plate When the lens is condensed after the lens, the incident light of this polarization state diverges after passing through the second flat lens, or when the incident light of the same polarization state diverges after passing through the first flat lens, the incident light of the polarization state passes through the second flat lens. Convergence after flat lens; The voltage control system is further configured to keep the second flat lens in a state of no electric field when a saturation voltage is applied to the first flat lens; and when applying a saturation voltage to the second flat lens, keep the second flat lens The first flat lens is in an electric field-free condition. 7. The vision correction device for presbyopia according to any one of claims 1 to 6, wherein the voltage control system can also be provided with a working mode sensor; The working mode sensor is used to detect whether the user's head is a head-down action for observing a close-up view, or a head-up or upward-looking action based on a long-range view; so that the voltage control system performs adaptive electric field state switching according to the corresponding detection result ; The voltage control system is also provided with a matching switch for the user to turn on or off the adaptive electric field switching based on the working mode sensor. 8. according to the arbitrary described presbyopia vision correction device of claim 1 to 6, it is characterized in that, when light beam is incident from polarizer end face, the angle between linear polarizer polarization direction and 1/4 wave plate fast axis direction is 45 ° , so that the polarization state of the outgoing beam from the wave plate is left-handed circularly polarized light. 9. The presbyopia vision correction device according to any one of claims 1 to 6, wherein when the light beam is incident from the end face of the polarizer, the angle between the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate is -45 °, so that the polarization state of the outgoing beam from the wave plate is right-handed circularly polarized light. 10. The vision correction device for presbyopia according to any one of claims 1 to 6, wherein when the light beam is incident from the end face of the flat lens, the angle between the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate is +45 °, so that the output beam of the linear polarizer is linearly polarized light with an included angle of +45° with the direction of the fast axis of the 1/4 wave plate. 11. The vision correction device for presbyopia according to any one of claims 1 to 6, wherein when the light beam is incident from the end face of the flat lens, the angle between the polarization direction of the linear polarizer and the fast axis direction of the 1/4 wave plate is -45 °, so that the outgoing beam of the linear polarizer is linearly polarized light with an included angle of -45° with the direction of the fast axis of the 1/4 wave plate. 12 . The vision correction device for presbyopia according to claim 1 , wherein the birefringent material is made of liquid crystal or liquid crystal polymer. 13 .

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