CN116212251A

CN116212251A - Light feeding device

Info

Publication number: CN116212251A
Application number: CN202211665245.7A
Authority: CN
Inventors: 吴丹磊; 陈荡荡; 和超
Original assignee: Beijing Yingtong Mingmu Information Technology Co ltd; Beijing Airdoc Technology Co Ltd
Current assignee: Beijing Yingtong Medical Technology Co ltd; Beijing Yingtong Mingmu Information Technology Co ltd; Beijing Airdoc Technology Co Ltd
Priority date: 2022-12-09
Filing date: 2022-12-23
Publication date: 2023-06-06
Also published as: CN116195965A; CN219185643U; CN219398737U; CN219185642U; CN116139414A; CN116549867A

Abstract

The present disclosure discloses a light feeding apparatus comprising: a red light source operative to generate red light for illuminating a fundus of a user; and a projection light path operative to receive the red light and project the red light toward the user's fundus, wherein the projection light path comprises a diffractive optical element device and a fixation light source, wherein the diffractive optical element is operative to deflect the red light in a direction such that the projection light path projects a spot of light at a predetermined region of the user's fundus; and the fixation light source is operative to illuminate the projected light path for directing the user to fixate on a spot center. By the scheme, personalized nursing light can be provided, and a user is guided to accurately watch the light spot center, so that efficient red light irradiation is realized, and eye axis growth is effectively restrained.

Description

Light feeding device

Technical Field

The present disclosure relates generally to the field of optical projection and imaging technology. More particularly, the present disclosure relates to a light feeding device.

Background

Eye axis growth is one of the major factors responsible for myopia in the human eye, especially for young people in rapid onset of age. Researches show that the long-wave red light of 650 nanometers (nm) is directly irradiated on the retina, so that the increase of the length of the eye axis can be effectively inhibited. Therefore, the irradiation of retina with red light has a positive effect on the prevention and control of myopia in teenagers.

There are some nursing devices currently on the market for myopia prevention and control. Such devices typically employ a dual barrel construction, one for each eye. Through the setting of mechanical structure, can adjust the interval between the binocular in order to adapt to the position of people's eye to the red light image coincidence that makes both eyes see. For illustrative purposes only, fig. 1 shows the basic light path structure of such a nursing device in the case of a single barrel. As shown in fig. 1, after exiting from the red light source, the red light enters the human eye through the light transmitting element and irradiates on the retina. In terms of selection and setting of the red light source, the red light source is generally selected as an LED light source or a laser light source having a wavelength around 650 nm. In addition, the light-transmitting element may be a transparent protective window plate or may be a light-transmitting lens to further converge or diverge the light beam emitted by the light source.

The working principle of the red light irradiation in the light feeding device is that the red light in the 650nm wave band has strong penetrability, and the red light simultaneously acts on the choroid after penetrating the retina. Since 650nm red light has a warming effect, bottleneck-like stenosis at the arteriole opening of the choroidal leaflet is opened, and blood flow into the leaflet is increased, thereby increasing microcirculation blood volume. Because the choroid thickness is increased without hypoxia of the sclera, the thinned choroid can be restored to normal thickness, sufficient oxygen is provided for the sclera and blood circulation of the fundus is improved, and myopia degree is not increased. In addition, 650nm red light can enable retinal epithelial pigment cells to secrete dopamine, so that excessive increase of an eye axis is effectively inhibited.

Although having remarkable effect on myopia prevention and control, the current light-feeding technology has some obvious defects. In particular, the currently commonly used red light source is a similar point light source, whether it is a light emitting LED or a laser diode, so that the light emitting area is small. When looking directly at the light source or observing the light source image after lens transformation, the human eye adjusts the central concave to face the light source itself, and sees a circular spot with higher central brightness, as shown in fig. 2. When the eye adjusts the photopic position to make the light source image clear, the size of the central bright spot is reduced, and the brightness of the bright spot is further increased, so that the visual stimulus to the eye is increased and the eye is further uncomfortable.

In addition to the fact that the smaller size of the light source causes stronger visual stimuli from the direct-view light source, this approach has a negative impact. In particular, when more red light energy is concentrated in the center of the macular region, the red light energy of the peripheral macular region is very weak. Thus, the illumination of the choroid in the macular area is unevenly stimulated, which in turn results in warming and uneven stimulation of the choroid, which ultimately affects the practical effect of red light irradiation to inhibit eye axis growth.

In view of this, there is a need to provide a solution for eye-feeding to provide targeted or personalized red illumination of the fundus to effectively inhibit eye axis growth.

Disclosure of Invention

To address at least one or more of the technical problems noted above, the present disclosure, in various embodiments, proposes a light feeding scheme for myopia prevention and control so as to achieve efficient red light illumination.

In particular, the present disclosure provides a light feeding apparatus for myopia prevention and control comprising: a red light source operative to generate red light for illuminating a fundus of a user; and a projection light path operative to receive the red light and project the red light toward the user's fundus, wherein the projection light path comprises a diffractive optical element device and a fixation light source, wherein the diffractive optical element is operative to deflect the red light in a direction such that the projection light path projects a spot of light at a predetermined region of the user's fundus; and the fixation light source is operative to illuminate the projected light path for directing the user to fixate on a spot center.

In one embodiment, the predetermined region of the user's fundus comprises a predetermined region of the macular region, wherein the predetermined region is divided according to the angle of the macular region.

In one embodiment, the projection light path includes: and a conjugate mirror group arranged between the exit end of the diffraction optical element device and the fundus of the user so that the position of the diffraction optical element device for deflecting the red light in the direction forms optical conjugate with the pupil position of the user.

In another embodiment, the conjugate mirror group includes a first conjugate mirror and a second conjugate mirror, wherein a front focal point of the first conjugate mirror is located at the diffractive optical element device, a back focal point of the first conjugate mirror coincides with a front focal point of the second conjugate mirror, and a back focal point of the second conjugate mirror is located at a pupil of the user.

In yet another embodiment, an intermediate image plane is formed where the back focal point of the first conjugate mirror coincides with the front focal point of the second conjugate mirror, and the projection optical path includes: a first beam splitter disposed between the first conjugate mirror and the intermediate image plane and configured to receive a light beam from a fixation light source to achieve optical conjugation of the fixation light source with a pupil location of a user.

In one embodiment, an intermediate image plane is formed where the back focal point of the first conjugate mirror coincides with the front focal point of the second conjugate mirror, and the projection optical path includes: and a second beam splitter disposed between the intermediate image plane and the second conjugate mirror and configured to receive a light beam from a fixation light source to achieve optical conjugation of the fixation light source with a pupil position of a user.

In one embodiment, the light feeding device further comprises: and the collimating mirror is arranged between the red light source and the diffraction optical element device and is used for converging and collimating the red light emitted by the red light source.

In another embodiment, the light feeding device further comprises: and the switching mechanism is operated to switch one of the diffraction optical element devices with the corresponding micro-nano structure into the projection light path according to different projection requirements.

In yet another embodiment, the different projection requirements correspond to spots having different preset patterns, and the spots having different preset patterns are generated based on different micro-nano structured diffractive optical element devices.

In one embodiment, the preset pattern includes a circular pattern or a ring pattern, wherein the ring pattern includes a ring with uniform color, a ring with gradually lighter color from outside to inside, a ring composed of a plurality of concentric circles with unequal radii, a ring composed of a plurality of line segments arranged radially around the same center, a ring composed of a grid pattern, or a ring composed of a lattice.

In one embodiment, the light feeding device further comprises a drive mechanism operative to perform at least one of the following drive to effect refractive compensation of the user's human eye by focusing: driving the second conjugate mirror to move relative to an intermediate image plane formed at a front focal point of the second conjugate mirror; and driving the red light source, the first conjugate mirror, the diffractive optical element device, the fixation light source, the first or second beam splitter and/or the collimator mirror to move relative to an intermediate image plane formed at a front focal point of the second conjugate mirror.

In one embodiment, the light feeding device further comprises a fixation projection lens operative to project a light beam from the fixation light source in a lens projection at the intermediate image plane location, the drive mechanism operative to drive movement of the first conjugate mirror and the diffractive optical element device relative to an intermediate image plane formed at a front focal point of the second conjugate mirror.

With the light feeding apparatus for myopia prevention and control provided above, embodiments of the present disclosure utilize diffractive optical element devices ("DOEs") to angularly deflect incident red light while maintaining the directionality of its laser light, thereby allowing a spot to be projected at a predetermined area of a user's fundus while introducing a fixation light source to direct the user's gaze at the center of the spot. Thus, aspects of the present disclosure may guide a user to accurately focus on a personalized or customized spot. When the personalized light spots are annular patterns, namely annular light spots are formed, the scheme disclosed by the invention can be convenient for the annular light spots projected on the fundus of a user to form red light annular energy distribution of a specific peripheral macular area avoiding the central concave of the macular area so as to realize efficient red light irradiation, thereby effectively inhibiting the growth of the ocular axis.

In some embodiments, by using a conjugate lens group (a 4F system described later), all angles of light energy generated by DOE diffraction can be conjugated (i.e. "projected") to the pupil into the human eye, thereby ensuring the nursing light power of the eye. In addition, by controlling the design of the magnification of the relevant lens group and the diffraction angle of the DOE device in the projection light path, the scheme disclosed by the invention can also realize the accurate control of the light in a specific area of the human eyes.

Further, in some embodiments, movement of the associated components in the disclosed light feeding apparatus may be driven by a drive mechanism to effect refractive compensation and determination of the base diopter of the human eye to facilitate detection of diopter.

Drawings

The above, as well as additional purposes, features, and advantages of exemplary embodiments of the present disclosure will become readily apparent from the following detailed description when read in conjunction with the accompanying drawings. Several embodiments of the present disclosure are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar or corresponding parts and in which:

FIG. 1 shows a schematic optical path diagram of a prior art light feeding device;

FIG. 2 shows a red light visual effect and energy distribution diagram of a prior art light feeding device;

FIG. 3 illustrates an optical schematic of a nursing device for myopia prevention and control of the present disclosure;

FIG. 4 shows a red light visual effect and energy distribution diagram of a light feeding device of an embodiment of the present disclosure;

FIG. 5 shows a schematic view of the focal position of a nursing device of an embodiment of the present disclosure;

FIG. 6 shows a schematic optical structure of a nursing device of one embodiment of the present disclosure;

FIG. 7 shows a schematic optical structure of a nursing device of another embodiment of the present disclosure;

FIG. 8 shows a schematic view of the axial spacing of a nursing device of an embodiment of the present disclosure;

FIG. 9a shows a schematic diagram of adjusting focus to achieve eye diopter compensation according to one embodiment of the present disclosure;

FIG. 9b shows a schematic diagram of adjusting focus to achieve refractive power compensation of a human eye in accordance with another embodiment of the present disclosure;

FIG. 9c shows a schematic diagram of an adjusted focus to achieve refractive power compensation of a human eye in accordance with yet another embodiment of the present disclosure;

FIG. 10 shows a schematic optical structure of a switchable DOE nursing device of an embodiment of the present disclosure; and

fig. 11 illustrates various exemplary diagrams of annular spots of embodiments of the present disclosure.

Detailed Description

The following description of the embodiments of the present disclosure will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the disclosure. Based on the embodiments in this disclosure, all other embodiments that may be made by those skilled in the art without the inventive effort are within the scope of the present disclosure.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the present disclosure is for the purpose of describing particular embodiments only, and is not intended to be limiting of the disclosure. As used in the specification and claims of this disclosure, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the term "and/or" as used in the present disclosure and claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As used in this specification and the claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to detection" depending on the context. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a [ described condition or event ]" or "in response to detection of a [ described condition or event ]".

Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

Exemplary application scenarios

The prior art light-feeding treatment apparatus generally employs a basic light path structure as shown in fig. 1, which is not ideal for the light-feeding effect of the human eye. The inventor finds through analysis and research that a key factor affecting the light feeding effect of the existing light feeding treatment equipment is that light source energy sources in human eyes are too concentrated and unevenly distributed. As described in the foregoing background, the light source in the light-feeding therapeutic apparatus has a small light-emitting area, and when looking directly at the light source or observing the light source image after lens conversion, the human eye adjusts the fovea to face the light source itself, and sees a circular spot with a high central brightness as shown in fig. 2. When the eye adjusts the photopic position to make the light source image clear, the size of the central bright spot can be reduced, and the brightness of the bright spot can be further increased, and the visual stimulus is increased to cause discomfort to the eye. In addition, the light source energy is distributed more intensively in the center of the macular region of the human eye, and is distributed weaker in the peripheral macular region. Thus, when the illumination stimulus to the choroid in the macular area is uneven, this in turn results in a warming effect and uneven stimulus to the choroid, and finally affects the actual effect of the red light irradiation to suppress the increase of the ocular axis.

Therefore, the inventor finds that an innovative light feeding device capable of projecting a light spot in a preset area of the fundus of a user and facilitating the user to watch the light spot correctly can be constructed, so that efficient red light irradiation can be realized, and the eye axis growth can be effectively restrained.

Exemplary light feeding device scheme

In view of the above, embodiments of the present disclosure provide a light feeding apparatus that guides a user to look at the center of a spot by using a DOE device to angularly deflect incident red light while maintaining the directionality of its laser light, thereby allowing the spot to be projected at a predetermined area of the user's fundus, and simultaneously introducing a fixation light source. In particular, in some embodiments, the micro-nano structure of the DOE device may be changed according to projection requirements, such that the present disclosure may provide personalized spots with different preset patterns. In other words, the scheme of the disclosure can realize accurate control of the nursing operation in a specific area by innovatively introducing a DOE device. In order to achieve a flexible and versatile illumination of the nursing light, the present disclosure may also utilize the above-mentioned switching mechanism to effect switching of multiple DOE devices so that a personalized spot with a preset pattern may be obtained quickly. In one implementation scenario, aspects of the present disclosure may provide an annular spot with a customized pattern through a DOE device. Thus, aspects of the present disclosure may achieve a red annular energy distribution of a particular peripheral macular region that avoids the fovea of the macular region.

In a scenario where the personalized spot is a circular spot, the scheme of the present disclosure may provide illumination with a uniform distribution of red light energy throughout the macular region. In a scene that the personalized light spot is an annular light spot, the scheme disclosed by the invention can guide a user to accurately watch the annular light spot, so that the annular light spot projected on the fundus of the user can form red light annular energy distribution of a specific peripheral macular area avoiding the central concave of the macular area, and the efficient red light irradiation is realized, so that the eye axis growth is effectively inhibited. In addition, as will be described later, the fixation light source of the present disclosure may be set according to different application scenarios and/or user preferences, for example, may be set at different positions of the projected light path or set to emit light of different colors, so that flexible light path arrangement and different user experiences may be achieved.

Fig. 3 shows a schematic optical path diagram of a nursing device for myopia prevention and control in accordance with embodiments of the present disclosure. As shown in fig. 3, a nursing device 301 may include a red light source 302 and a transmission light path, which illustratively contains a DOE (Diffractive Optical Element, "DOE") device 303 and a fixation light source 304. From a reading of the context, it will be appreciated that the projected optical path of the present disclosure may add additional optics depending on the application requirements, build an optical path suitable for the innovative principles of the present disclosure or make changes to the exemplary optical path structure of the present disclosure, while still falling within the scope of the present disclosure. In addition, for clarity of illustration of the optical path principle of the nursing device, a user's human eye (or fundus) 305 is also schematically shown in fig. 3.

For ease of understanding, fig. 3 further illustrates a human eye fundus structure. In particular, the figure shows the angular distribution of the macular region of the fundus. For example, it has an angular distribution of 15 degrees for all macular regions; for the peripheral macular area, it has an angular distribution of 8 degrees; for the fovea, it has an angular distribution close to 5 degrees. For such angular distribution, the micro-nano structure of the DOE device may be tailored accordingly to produce, when introduced into the projection optical path of the present disclosure, a spot corresponding to the aforementioned region of the specific angular distribution of the macular region. With respect to custom fabrication of DOE device micro-nano structures, it is within the scope of the prior art. This application does not describe this too much in order to avoid unnecessarily obscuring aspects of the present disclosure.

During the nursing period, the aforementioned red light source 302 operates to generate red light for illuminating the fundus of the user. In some implementations, the red light source 302 may employ a laser diode or other electronic device capable of producing a coherent light source. It should be noted that the specific type of the red light source is not limited in this disclosure, and may be selected according to actual requirements.

In application, the projection light path described above may be operative to receive red light and project the red light toward the fundus of the user. To this end, the projection light path of the present disclosure may specifically include a DOE device 303 and a fixation light source 304. In one embodiment, based on the physical characteristics and functionality of the DOE device 303, it may be precisely operable to deflect the aforementioned red light in a direction such that the projected optical path may project an annular spot at the user's fundus 305. For this purpose, a specific directional deflection of the red light can be obtained, for example, by processing the micro-nano structure of the DOE device for specific requirements. Further, the illustrated fixation light source 304 is operable to illuminate the projected light path for guiding the fixation spot center. Specifically, when the fixation light source 304 is acting in the projected light path, a fixation point may be generated at the center of the spot to guide the human eye to focus on the fixation point. In some embodiments, the fixation light source 304 may employ the same light source as the red light source 302, or may employ a light source of a different color than red light, such as green, blue, etc., as previously described, so that the human eye is more likely to focus on the annular spot center and obtain a user experience similar to its preferences.

For illustrative purposes only, the energy distribution of an annular spot with a fixation point is shown in fig. 4, where a fixation light source acts in the projected light path to form a spot in the middle of the annular region (in the middle of the fovea of the macular area in the figure) for fixation function, with an energy cross-sectional distribution as shown in curve 401. It can be seen that when the user gazes at the annular spot, the user may gaze at the center of the annular spot under the guidance of the fixation light source, and the annular spot projected on the fundus 305 of the user may avoid the central recess of the macular region and be uniformly distributed in the peripheral macular region, the energy cross-section distribution of which is shown as curve 402. Therefore, high-efficiency red light irradiation can be realized, and meanwhile, the stimulation of vision caused by the concentration of energy in a central concave part can be avoided, and the annular light spots distributed on the periphery based on the energy can generate uniform illumination stimulation on the veins of a macular region, so that the warm effect and the uniform stimulation on the choroid are ensured, and the effective light-feeding treatment on human eyes is realized. It will be appreciated that for a circular spot, it may provide a nursing light with an even distribution of red light energy throughout the macula area.

FIG. 5 shows a schematic view of the focal position of a nursing device of an embodiment of the present disclosure.

In one exemplary application, divergent red light generated by a red light source (e.g., a red laser light source) is collimated out by a collimating mirror and impinges on a DOE device. The red light is emitted from the DOE device, enters a 4F optical system composed of a first conjugate mirror and a second conjugate mirror, and projects a light spot from the 4F optical system to a predetermined area (such as a certain angle distribution area of a macular region) of the fundus of the user. Specifically, as shown in fig. 5, in the 4F system, the front focal point of the first conjugate mirror is located at the diffractive optical element device, the back focal point of the first conjugate mirror coincides with the front focal point of the second conjugate mirror, and the back focal point of the second conjugate mirror is located at the pupil of the user. Wherein the front focal point of the first conjugate mirror is located at the DOE device, i.e. where the red light produces an angular distribution. And the back focus of the first conjugate mirror coincides with the front focus of the second conjugate mirror, and the red light deflected by the DOE device generates a converged intermediate image plane at the focus, so as to obtain the energy distribution of the predetermined pattern (such as a circle or a ring). The purpose of this arrangement is to optically conjugate the position of the DOE device where the red light is angularly deflected with the pupil position of the human eye so that all light generated by the DOE device can enter the pupil of the human eye, and to optically conjugate the energy spatial distribution of the intermediate image plane with the fundus of the human eye and to project the energy distribution of the intermediate image plane onto the fundus retina.

It can be seen that, the DOE device generates an angular deflection corresponding to the predetermined region of the fundus, and simultaneously maintains the specific directionality of the laser, and in combination with the subsequent 4F system, the scheme of the present disclosure can conjugate the light energy of all angles generated by the DOE device diffraction to the pupil to enter the human eye, so as to effectively ensure the light power of the light entering the eye, and obtain the myopia prevention effect which cannot be achieved by the light-feeding device in the prior art.

As mentioned previously, the scheme of the present disclosure can also achieve precise control over the area of human eye nursing by controlling the magnification of the 4F system and the design of the diffraction angle of the DOE device. For this reason, in some embodiments, the diameter of the collimated light spot of the red light is set to be D1, the maximum deflection half angle that can be achieved by the DOE device is set to be f1 for the focal length of the first conjugate mirror in the θ 1,4F system, f2 for the focal length of the second conjugate mirror, D2 for the pupil diameter of the human eye, and the maximum included angle between the red light entering the pupil and the optical axis is set to be θ2. Based on such a setting, the conjugate magnification of the 4F system of the present disclosure is m=f2/F1, whereby there is a correspondence relationship of D2/d1=m, θ1/θ2=m. Based on this, for the determined fundus illumination angle range θ2 and pupil diameter D2, the diffraction angle θ1 of the matching DOE and the diameter D1 of the collimated light spot can be selected according to the focal length ratio of the 4F system. Meanwhile, different collimation spot diameters can be realized by selecting different divergence angles of red light sources (such as red laser diodes) and focal lengths of the collimation lenses.

FIG. 6 shows a schematic optical structure of a nursing device of one embodiment of the present disclosure. It will be appreciated that FIG. 6 is a specific implementation of the light device of FIG. 3. Accordingly, the foregoing detailed description in connection with fig. 3 applies equally as well to the following.

In this embodiment, the nursing device may include a red light source and a projection light path. The projection light path comprises a DOE device, a fixation light source and a conjugate lens group. The conjugate mirror group may be used to optically conjugate the position of the DOE device that deflects the direction of the red light with the user's pupil position. According to different application scenes, the conjugate lens group can be realized through the cooperation of a plurality of optical devices, and the specific position of the conjugate lens group in a projection light path can be set according to the specific structure of the conjugate lens group. For example, in some embodiments, the conjugate mirror group may be disposed between the exit end of the diffractive optical element device and the fundus of the user so as to optically conjugate the position of the diffractive optical element device that deflects the red light in the direction to the pupil position of the user.

Specifically, as shown in fig. 6, the foregoing conjugate lens group may include a first conjugate lens and a second conjugate lens, with a front focal point of the first conjugate lens being located at the diffractive optical element device, a back focal point of the first conjugate lens being coincident with a front focal point of the second conjugate lens, and a back focal point of the second conjugate lens being located at the pupil of the user. The first conjugate mirror and the second conjugate mirror can be of a single-piece or multi-piece mirror group structure. Further, the nursing device also includes a collimating mirror that may be disposed between the red light source and the diffractive optical element device. Thus, the red light emitted by the red light source is converged and collimated based on the collimating lens.

In fig. 6, an intermediate image plane is formed where the back focal point of the first conjugate mirror coincides with the front focal point of the second conjugate mirror. Further, the projection light path further includes a first beam splitter, a fixation projection lens, and a fixation light source. As an example, the fixation light source is arranged above the first spectroscope, and the first spectroscope is arranged between the first conjugate mirror and the intermediate image plane for receiving the light beam from the fixation light source from the fixation projection mirror to achieve optical conjugation of the fixation light source with the pupil position of the user. In other embodiments, the position of the first beam splitter may be adjusted according to design requirements. For example, as shown in fig. 7, a second beam splitter (which has similar physical characteristics and functions to the first beam splitter) may be disposed between the aforementioned intermediate image plane and the second conjugate mirror and configured to receive the light beam from the fixation light source to achieve optical conjugation of the fixation light source to the pupil location of the user.

It should be noted that fig. 7 is understood to be another specific implementation of the light feeding device in fig. 3, and the working principle of the light feeding device is the same as that of fig. 6, and the difference is only that the positions of the beam splitter and the fixation light source are different. For example, it is preferable to use a point light source of a color other than red light as the fixation light source, and introduce the fixation light source into the main optical path by using a spectroscope, and penetrate the second conjugate mirror to enter the human eye. The beam splitter is used for transmitting red light of the main light path and reflecting one path of the fixation light source so as to realize the combination of the two light beams. Next, the fixation light source is located at the front focal point of the second conjugate mirror so as to optically conjugate the fixation light source with the fundus. In some implementations, the beam splitter may include a dichroic mirror that splits light at a wavelength or a beam splitter that splits light at an energy ratio.

In practical use, when the human eye is in a normal refractive state (for example, the human eye is a normal human eye or a normal human eye compensated by wearing glasses, contact lenses, etc.), the optical element in the light feeding device (for example, fig. 6 or fig. 7) does not need to perform focusing operation, and the position of the optical element is relatively fixed. When the human eye is a near/far vision human eye, the nursing device can realize clear focusing by adjusting one group of elements so that the human eye can see the fixed point of view clearly. In principle, the main red light and the fixation light source in the light feeding device can generate a real image surface at the middle image surface position when passing through the projection light path. When the distance between the intermediate image plane and the front focus of the second conjugate mirror is relatively changed, the converging or diverging state of the red light output from the second conjugate mirror is changed. If the human eye is in a near vision state (i.e. a certain diopter exists), the parallel light output by the second conjugate mirror will fall in front of the retina of the human eye. In view of this, the solution of the present disclosure proposes to reduce the distance between the intermediate image plane and the front focal point of the second conjugate mirror so that the red light taken into the human eye from the second conjugate mirror is in a divergent state, so that the red light can be made to fall on the retina of the human eye. Therefore, the refraction compensation of human eyes can be realized by enabling the intermediate image surface where the red light and the fixation point are located to be offset from the front focal point of the second conjugate mirror in the optical axis direction.

Additionally or alternatively, the basic diopter information of the tested human eye can also be converted by the axial difference value (axial distance delta shown in fig. 8) between the front focus of the second conjugate mirror and the intermediate image plane. Here, the adjustment of the axial spacing may include an active feedback adjustment, such as a user actively adjusting the amount of refractive compensation based on the sharpness of the fixation point. In this case, the user can adjust the refractive compensation amount adjustment manually or electrically.

In one embodiment, the foregoing correspondence between the axial distance Δ (mm) between the intermediate image plane and the front focal point of the second conjugate mirror and the human eye diopter D is: d=1000Δ/(f2+Δ)), wherein the focal length of the second conjugate mirror is f2 (mm). It will be appreciated that delta is positive when the intermediate image plane is referenced to and away from the front focal point of the second conjugate mirror.

Further, the aforementioned means for making the accommodation of the refractive power compensation of the human eye may be achieved by a variety of means. To this end, in some embodiments, the light feeding device of the present disclosure may also be provided with one or more drive mechanisms (e.g., stepper motors) that drive the second conjugate mirror to move relative to an intermediate image plane formed at the front focal point of the second conjugate mirror, and/or drive the red light source, the first conjugate mirror, the DOE device, the fixation light source, the first spectroscope (or the second spectroscope), and/or the collimator mirror to move relative to an intermediate image plane formed at the front focal point of the second conjugate mirror.

For example, for a nursing device having the structure shown in fig. 9a and 9b, the refractive compensation adjustment may be performed with front set focusing. As shown in fig. 9a and 9b, the driving mechanism can drive the relevant optical devices of the fixation light source and the red light feeding to link, so that the positions of the fixation light source and the intermediate image surface are kept consistent, and the intermediate image surface is offset from the front focus of the second conjugate mirror, thereby realizing refractive compensation adjustment. Specifically, the red light source, the first conjugate mirror, the DOE device, the fixation light source, the spectroscope (i.e., the first or second spectroscope) and the collimating mirror can be linked to realize refraction compensation adjustment.

Further, as shown in FIG. 9a, the nursing device may also include a fixation projection lens. The fixation projection lens is operable to project a light beam from a fixation light source at an intermediate image plane location in a lens projection manner. In the refractive compensation adjustment by means of front group focusing, the first conjugate mirror and the DOE device may also be driven to move by means of a driving mechanism with respect to an intermediate image plane formed at the front focal point of the second conjugate mirror. Because the alignment diameter of the collimated red light is insensitive to the change of the distance between the DOE devices, the collimating mirror, the red light source and the like can not be adjusted in the application scene.

For another example, the refractive compensation adjustment may also be performed by means of a back-group focusing. Specifically, the second conjugate mirror may be driven to move by a driving mechanism with respect to an intermediate image plane formed at a front focal point of the second conjugate mirror. As shown in fig. 9c, the axial position of the second conjugate mirror may be adjusted by a driving mechanism (moved left and right as shown) to achieve convergence and divergence of the nursing light entering the human eye, thereby compensating the diopter of the human eye.

Further, in some embodiments, the spots in the present disclosure may have different preset patterns according to different projection requirements, and each preset pattern corresponds to a micro-nano structured diffractive optical element device. As shown in fig. 10, in use, a switching mechanism (e.g., a slot mechanism for supporting the detachable mounting of the DOE device, etc.) may be provided in the light-feeding device, and one of the diffractive optical element devices having a corresponding micro-nano structure may be switched into the projection optical path according to the transmission requirements based on the switching mechanism.

In some implementations, the foregoing annular spot may have a preset pattern as shown in fig. 11. For example, the preset pattern may include a ring shape having a uniform color, a ring shape having a gradually lighter color from the outside to the inside, a ring shape composed of a plurality of concentric circles having different radii, a ring shape composed of a plurality of line segments arranged radially around the same center, a ring shape composed of a mesh pattern, or a ring shape composed of a lattice. It should be noted that fig. 11 is only an exemplary illustration of a portion of the preset pattern, and the preset pattern that may be provided by the annular light spot in the present disclosure is not limited thereto. For example, in some application scenarios, the annular spot of the present disclosure may also have a deformed, rotated, or combined pattern form of the pattern shown in fig. 11.

In summary, the solution of the present disclosure may achieve red illumination of a specific region of the fundus, and may reduce or equalize the red illuminance of the fovea, thereby avoiding causing intense visual stimulus. At the same time, the red light energy distribution in the peripheral macular area is also increased. In addition, a fixation point is generated by introducing a fixation light source to assist a user to aim at the center of the light spot area, and a visual target is provided for reading refractive information of human eyes. In addition, the basic refractive information of human eyes can be obtained in an active feedback mode of a user. It is emphasized that the description of the projected light path of the present disclosure is merely exemplary and not limiting, and that modifications of the light path to accommodate different application scenarios may also be made by those skilled in the art in light of the teachings of the present disclosure, while still falling within the scope of the present disclosure.

While various embodiments of the present disclosure have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous modifications, changes, and substitutions will occur to those skilled in the art without departing from the spirit and scope of the present disclosure. It should be understood that various alternatives to the embodiments of the disclosure described herein may be employed in practicing the disclosure. The appended claims are intended to define the scope of the disclosure and are therefore to cover all equivalents or alternatives falling within the scope of these claims.

Claims

1. A nursing device, comprising:

a red light source operative to generate red light for illuminating a fundus of a user; and

a projection light path operative to receive the red light and project the red light toward the fundus of the user, wherein the projection light path comprises a diffractive optical element device and a fixation light source, wherein

The diffractive optical element is operative to deflect the red light in a direction such that the projection light path projects a spot at a predetermined region of the user's fundus; and

the fixation light source is operative to illuminate the projected light path for directing the user to fixate on a spot center.

2. The light feeding device of claim 1, wherein the predetermined area of the user's fundus comprises a predetermined area of the macular area, wherein the predetermined area is divided according to the angle of the macular area.

3. The light feeding device of claim 1, wherein said projection light path comprises:

and a conjugate mirror group arranged between the exit end of the diffraction optical element device and the fundus of the user so that the position of the diffraction optical element device for deflecting the red light in the direction forms optical conjugate with the pupil position of the user.

4. The light feeding device of claim 2, wherein the conjugate lens group comprises a first conjugate lens and a second conjugate lens, wherein a front focal point of the first conjugate lens is located at the diffractive optical element device, a back focal point of the first conjugate lens coincides with a front focal point of the second conjugate lens, and a back focal point of the second conjugate lens is located at a pupil of a user.

5. The light feeding device of claim 3, wherein an intermediate image plane is formed where a back focal point of said first conjugate mirror coincides with a front focal point of said second conjugate mirror, and said projection light path comprises:

a first beam splitter disposed between the first conjugate mirror and the intermediate image plane and configured to receive a light beam from a fixation light source to achieve optical conjugation of the fixation light source with a pupil location of a user.

6. The light feeding device of claim 3, wherein an intermediate image plane is formed where a back focal point of said first conjugate mirror coincides with a front focal point of said second conjugate mirror, and said projection light path comprises:

and a second beam splitter disposed between the intermediate image plane and the second conjugate mirror and configured to receive a light beam from a fixation light source to achieve optical conjugation of the fixation light source with a pupil position of a user.

7. The light feeding device of claim 1, further comprising:

and the collimating mirror is arranged between the red light source and the diffraction optical element device and is used for converging and collimating the red light emitted by the red light source.

8. The light feeding device of claim 1, further comprising:

and the switching mechanism is operated to switch one of the diffraction optical element devices with the corresponding micro-nano structure into the projection light path according to different projection requirements.

9. The light feeding device of any one of claims 3-7, wherein the different projection requirements correspond to spots having different preset patterns, and the spots having different preset patterns are generated based on different micro-nanostructured diffractive optical element devices.

10. The light feeding device of claim 9, wherein the predetermined pattern comprises a circular pattern or a ring pattern, wherein the ring pattern comprises a ring shape having a uniform color, a ring shape having a gradually lighter color from the outside to the inside, a ring shape composed of a plurality of concentric circles having different radii, a ring shape composed of a plurality of line segments arranged radially around the same center of a circle, a ring shape composed of a grid-shaped pattern, or a ring shape composed of a lattice.

11. The light feeding device of claim 8, further comprising a drive mechanism operative to perform at least one of the following drive to effect refractive compensation of a user's human eye by focusing:

driving the second conjugate mirror to move relative to an intermediate image plane formed at a front focal point of the second conjugate mirror; and

the red light source, the first conjugate mirror, the diffractive optical element device, the fixation light source, the first or second beam splitter, and/or the collimator lens are driven with respect to an intermediate image plane formed at a front focal point of the second conjugate mirror.

12. The light feeding device of claim 9, further comprising a fixation projection mirror operative to project a light beam from said fixation light source in a lens projection manner at said intermediate image plane location, said drive mechanism operative to drive movement of said first conjugate mirror and said diffractive optical element device relative to an intermediate image plane formed at a front focal point of said second conjugate mirror.