CN115414001B

CN115414001B - Projection device based on cornea reflection, cornea photo-projector, cornea topography instrument and detection method thereof

Info

Publication number: CN115414001B
Application number: CN202210975134.XA
Authority: CN
Inventors: 于航; 王立峰; 陈海银
Original assignee: Hangzhou Weixiao Medical Technology Co ltd
Current assignee: Hangzhou Weixiao Medical Technology Co ltd
Priority date: 2022-08-15
Filing date: 2022-08-15
Publication date: 2023-05-05
Anticipated expiration: 2042-08-15
Also published as: CN115414001A; WO2024037035A1

Abstract

The invention discloses a projection device based on cornea reflection, a cornea photo-projector, a cornea topographic map instrument and a detection method thereof, and belongs to the field of ophthalmology. The invention comprises a light source mechanism, a platy projection disk and a first movement mechanism, wherein the light source mechanism is provided with a light output end, the light source mechanism is used for outputting a hollow cone beam taking a preset eye axis as an axis at the light output end and projecting annular light on a first side of the projection disk, and the first movement mechanism contracts and expands the annular light by adjusting the relative positions of the light output end and the projection disk in the preset eye axis direction; the cornea on the second side of the projection disk receives the annular light to form reflected light, the reflected light passes through the reflecting part of the projection disk, and the reflecting part is positioned at the center of the annular light and is coaxial with the annular light. In the invention, the projection device based on cornea reflection realizes the functions of the existing Placido module with lower manufacturing cost.

Description

Projection device based on cornea reflection, cornea photo-projector, cornea topography instrument and detection method thereof

Technical Field

The invention relates to the field of ophthalmology, in particular to a projection device based on cornea reflection, a cornea photo-projector, a cornea topographic map instrument and a detection method thereof.

Background

The corneal topography is characterized in that the surface of the cornea is taken as a local topography, and different methods are adopted for recording and analyzing, and the topography is called as the corneal topography because of the seemingly-shaped topography of the surface of the topography. The corneal topography can reflect the morphological changes of the cornea surface, and the type of curvature and astigmatism of the cornea of a detector can be judged from the topography of the front and rear surfaces of the cornea, and even whether keratoconus is likely to occur can be found in advance.

Corneal topographers are devices for detecting corneal topography, and Placido-based corneal topographers are widely used. The Placido disk is made of transparent materials and comprises a conical cylinder structure with a small hole in the middle, and a plurality of concentric rings (respectively, a bright ring and a dark ring) are arranged on the inner surface of the conical cylinder, wherein the dark ring is used for shielding light spots and is formed by spraying organic ink; the bright ring is used for transmitting light. The cornea topography instrument based on the Placido disk further comprises an illumination system, a camera system and an image processing system, wherein the cornea topography instrument projects concentric circular images on the Placido disk onto the surface of a cornea, the cornea generates reflected light, the camera system collects the reflected light to form a virtual image and inputs the virtual image into the image processing system, the image processing system processes the virtual image to obtain a cornea topography, specifically, the illumination system irradiates the Placido disk, light enters the cornea through the bright ring, the light reflected by the cornea passes through a small hole in the center of the Placido disk and enters the camera system, and image information collected by the camera system is fitted or subjected to other processing through the image processing system to obtain the cornea topography.

In clinical examination of the cornea, in addition to analyzing the cornea condition of a subject by acquiring a corneal topography, some information of the subject's cornea can be acquired by observing the morphology of the cornea. The Chinese patent publication No. CN207136833U published in 3/27/2018 discloses a handheld Placido cornea photo-graph, which uses Placido disc to project light to cornea of observed person, and the light reflected by cornea of observer is captured by observer after amplified by objective lens and ocular lens, as basis for judging astigmatism information.

From the above, it is known that the conventional Placido-based corneal topographer and corneal photo-projector both include a Placido module formed by the Placido disc and an illumination system, the Placido module is equivalent to a projection device for projecting toward the cornea, and the Placido module captures information of cornea reflection by projecting annular light toward the cornea, but the Placido module has the following drawbacks:

(1) The Placido disk needs to process a bright ring and a dark ring which are arranged alternately, and the manufacturing precision is greatly limited by materials and processes, so that the processing precision of the Placido module is difficult to improve; especially, placido discs applied to a cornea map instrument are irregular in shape, and a bright ring and a dark ring are arranged on the inner surface of a conical cylinder in a ring mode, so that requirements of manufacturing accuracy on materials, processing technology and processing equipment are improved;

(2) At present, the number of Placido disc rings is generally 24-34, the machining precision of each ring is required to be 10um, and the process for machining high-precision bright rings and dark rings on Placido discs is complex, so that the machining cost of Placido modules is high;

(3) The width of the ring on the Placido disk directly influences the detection precision of the cornea topography instrument and the observation result of the cornea photo instrument, the smaller the width of the ring is, the higher the detection precision is, but the reduction of the width of the ring has higher challenges in technical research and development and configuration of matched processing technology;

(4) The precision of the Placido module is not adjustable, and in specific application, a fixed Placido disc is arranged on a cornea topographic map instrument and a cornea photo instrument, parameters of a bright ring and a dark ring of the Placido disc are not adjustable, so that the detection precision of the cornea topographic map instrument and the observation precision of the cornea photo instrument are also not adjustable, correspondingly, the cornea topographic map instrument with low precision is suitable for the working condition with high requirements on the precision of the cornea topographic map, and the cornea photo instrument with low precision has the risk of misdiagnosis;

(5) Subject to the working principle of Placido discs, the information obtained by the corneal topographer and the corneal photo-lithographer is only the corneal information at the positions corresponding to the bright ring of Placido, and is not continuous information characterizing the surface morphology of each position of the cornea. The corneal topographer needs to fit the intermittent information through a complex image processing algorithm to obtain a topographic map. Thus, the data output by the corneal topographer and the corneal imager do not fully truly represent the actual situation at all locations of the cornea.

Disclosure of Invention

It is an object of the present application to provide a projection device, a cornea imager, a cornea topography apparatus and a method for detecting the same, which output information of cornea reflection by projecting annular light to the cornea, which is an alternative to the Placido module composed of the existing Placido disc and the illumination system, and which has the effect that the manufacturing accuracy is independent of materials, processing technology and processing equipment, and the manufacturing cost is low.

In order to achieve the above object, the present invention provides the following technical solutions.

The projection device based on cornea reflection comprises a light source mechanism, a platy projection disk and a first movement mechanism, wherein the light source mechanism comprises a light output end, the light source mechanism is used for outputting a hollow cone light beam taking a preset eye axis as an axis at the light output end and projecting annular light on a first side of the projection disk, and the first movement mechanism is used for shrinking and expanding the annular light by adjusting the relative position between the light output end and the projection disk in the preset eye axis direction; the cornea positioned on the second side of the projection disc receives the annular light to form reflected light, and the reflected light can pass through the reflecting part of the projection disc and then change the light path; the reflecting portion is located at the center of the annular light and is coaxial with the annular light.

Optionally, the light source mechanism includes light source module and plastic module, the light source module can emit parallel light, the plastic module is used for with the parallel light turns into hollow cone beam.

Optionally, the diameter of the parallel light emitted by the light source module is adjustable, and the thickness of the hollow cone beam output by the shaping module changes along with the change of the diameter of the parallel light.

Optionally, the light source module includes light source, first lens module, second lens module and third lens module, first lens module is used for receiving the parallel light of light source, the second lens module is used for propagating light between first lens module and the third lens module, the third lens module is used for outputting parallel light in predetermine the eye axis direction, first lens module and/or second lens module and/or the position of third lens module is adjustable.

Optionally, the light source module further includes a second movement mechanism and/or a third movement mechanism, where the second movement mechanism is used to drive the first lens module to move along the preset eye axis direction, and the third movement mechanism is used to drive the second lens module to move along the preset eye axis direction.

Optionally, the light source module is a continuous zoom beam expander.

Optionally, the shaping module comprises a conical lens opposite to the shaping module, and parallel light of the light source module is converted into a hollow conical light beam through the conical lens; or,

the shaping module comprises a mounting piece and a plurality of conical lenses, wherein the conical lenses are mounted on the mounting piece, and the mounting piece is used for adjusting the positions of the conical lenses so that the axis of any conical lens coincides with the preset eye axis.

Optionally, the first movement mechanism drives the projection disk to move relative to the light source mechanism, or the first movement mechanism drives the light source module and the shaping module to move together relative to the projection disk, or the first movement mechanism drives the shaping module to move relative to the light source module and the projection disk.

Optionally, the first motion mechanism includes a driving module and a detection feedback module, the driving module is used for adjusting the relative positions of the light source mechanism and the projection disk in the preset eye axis direction, and the detection feedback module is used for obtaining the relative displacement of the light source mechanism and the projection disk; the detection feedback module comprises a linear grating ruler.

Optionally, the first surface of the projection disk facing the light source mechanism is a plane, a sphere, an ellipsoid, a paraboloid, a hyperboloid, an aspheric surface or a free-form surface; wherein, the spherical radius is between 100mm and 300 mm;

the second surface of the projection disk, which faces away from the light source mechanism, is a plane.

Optionally, at least one of a first surface of the projection disk facing the light source mechanism and a second surface facing away from the light source mechanism is frosted;

the projection disk is made of glass or plastic.

A cornea imager comprising the projection device based on cornea reflection and an observation module, wherein the observation module comprises an incident end and an observation end, reflected light passes through the reflection part and then enters the incident end, and propagates to the observation end along a preset direction under the action of the incident end, and the preset direction is inclined or vertical relative to the direction of the preset eye axis.

A corneal topographer, comprising:

the corneal reflection-based projection device of any one of the above;

and the imaging module is used for receiving the reflected light and image information.

Optionally, the imaging module includes a first end and a second end, wherein the first end is configured as a beam splitter structure for receiving the reflected light and transmitting the reflected light to the second end, and the first end to the second end are arranged along a direction perpendicular to the preset eye axis.

Optionally, the imaging module includes a beam splitter element, an imaging lens group and an image sensor, the reflected light is reflected into the imaging lens group by the beam splitter element, and the imaging lens group focuses the light on the image sensor.

The optional first motion mechanism is used for driving the shaping module to move relative to the light source module and the projection disc, the imaging module and the shaping module are arranged to be relatively static, and the spectroscope element is provided with a through hole for the light output end to pass through.

Optionally, the first movement mechanism is configured to drive the shaping module and the imaging module together to move relative to the light source module and the projection disk, and the beam splitter element and the image sensor are configured to be stationary relative to the shaping module, and the imaging lens group is configured to move between the beam splitter element and the image sensor to focus light on the image sensor.

Optionally, the corneal topography instrument further comprises an image processing module for calculating and/or analyzing the image information;

the cornea topography instrument further comprises a mounting cover, a mounting cavity is formed by the mounting cover in a surrounding mode, and the projection device based on cornea reflection and the imaging module are arranged in the mounting cavity.

A method of corneal topography detection implemented using a corneal topography instrument as defined in any one of the preceding claims for detecting a cornea located on a second side of the projection disc, the method comprising the steps of:

controlling the first movement mechanism to drive the light output end and the projection disk to move relatively for a first distance in the preset eye axis direction, and controlling the imaging module to shoot and obtain a plurality of image information during the period;

and superposing the image information.

Optionally, the controlling the first movement mechanism drives the light output end and the projection disk to relatively move a first distance in the preset eye axis direction, and during that, the imaging module is controlled to shoot and obtain a plurality of image information:

the first movement mechanism is used for outputting electrodeless movement and controlling the first movement mechanism to drive the projection disk to move at a uniform speed for a first distance relative to the light output end, and the imaging module shoots according to a preset frequency.

The projection disc and the light output end are controlled to move relatively for a plurality of times to reach the relative movement amount of the first distance, the movement amount of each relative movement of the projection disc and the light output end is the same, and the imaging module is controlled to shoot at the gap between the two relative movements.

Optionally, the step of driving, by the first movement mechanism, the light output end and the projection disk to relatively move in the preset eye axis direction by a first distance, and controlling the imaging module to capture and obtain a plurality of image information during the period further includes:

and adjusting the initial distance between the light output end and the projection disc, and/or adjusting the relative movement speed between the light output end and the projection disc, and/or adjusting the shooting frequency of the imaging module, so that the outer diameter of the annular light corresponding to the (n+1) th shooting of the imaging module is equal to the inner diameter of the annular light corresponding to the (n) th shooting.

Compared with the prior art, the beneficial effect of this application lies in:

(1) Because the projection disc only needs to adopt the light-transmitting plate, such as a frosted glass plate, the existing mature product can be directly adopted, the shape of the conical cylinder body does not need to be processed, organic ink does not need to be sprayed to shield light, and the light source mechanism and the first movement mechanism do not need to develop special processing equipment and working procedures for processing, so that the manufacturing precision of the projection device based on cornea reflection does not depend on the materials and the production process of the projection disc, the first movement mechanism and the light source mechanism, and the problem that the manufacturing precision is difficult to improve due to the limitation of the materials and the process does not exist.

(2) The annular light projected to the cornea is generated by emitting a hollow cone beam through a light source mechanism, only one beam of annular light is arranged on a projection disc under each transient state, the cornea correspondingly outputs a group of reflected light, a plurality of groups of reflected light can be obtained by capturing a plurality of transient states, and comprehensive and accurate cornea form information can be obtained after the information of each group of reflected light is overlapped; under the condition that the relative movement of the projection disk and the light source mechanism is the same for a certain distance, the ring width of the annular light is reduced, the interval duration between two adjacent transients is reduced, the number of groups of reflected light is more, the effect of increasing the number of rings of the conventional Placido disk is the same, namely, the detection precision is improved, but the ring width of the annular light is reduced, the interval duration between the two adjacent transients is reduced without complex technology, and the implementation is easy.

(3) When capturing a plurality of transients to obtain a plurality of groups of reflected light, the relative positions between the projection disk and the light output end are adjusted, so that the radial sizes of the annular light in adjacent transients are partially overlapped or seamlessly connected, the information of the whole cornea can be obtained after the reflected light in a plurality of transients is overlapped, and compared with intermittent data output by the conventional Placido disk, the data of the projection device based on cornea reflection are continuous and more accurate.

Drawings

The technical features and advantages of the present invention may be more fully understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic view of a projection device based on corneal reflection according to embodiment 1 of the present invention;

FIG. 2 is a schematic view of a projection device based on corneal reflection according to embodiment 1 of the present invention;

FIG. 3 is a side view of a projection disk in accordance with an embodiment of the present invention;

FIG. 4 is a graph showing the comparison of the output beam of the shaping module according to embodiment 2 of the present invention, wherein the thickness of the hollow cone beam output by the shaping module is changed when the diameter of the parallel beam received by the shaping module is changed;

FIG. 5 is a structural comparison diagram of the light source module of embodiment 2 of the present invention under three transients;

FIG. 6 is a schematic view of the structure of a corneal topographer according to example 4 of the present invention;

FIG. 7 is a schematic view showing the structure of a corneal topographer according to example 5 of the present invention;

FIG. 8 is a schematic view showing the structure of a corneal topographer according to example 6 of the present invention;

FIG. 9 is a flow chart of a method for detecting corneal topography of example 7 of the present invention;

fig. 10 is a schematic view of a projection device based on corneal reflection according to an embodiment of the present invention.

Reference numerals

Light source mechanism 10

Light output end 101

Hollow cone beam 102

Light source module 103

First lens module 1031

Second lens module 1032

Third lens module 1033

Light source 1034

Shaping module 104, 104'

Projection disk 20

First side 201

Second side 202

Reflection unit 203

First surface 204

Second surface 205

First movement mechanism 30

Preset eye axis 40

Imaging module 50

First end 501

Second end 502

Spectroscope element 503

Through hole 5031

Imaging lens group 504

Image sensor 505

Reflected light 60

Cone lens 70 turntable 71 on shaping module 104

Detailed Description

Unless defined otherwise, technical or scientific terms used in the specification and claims should be given the ordinary meaning as understood by one of ordinary skill in the art to which the invention pertains.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art in a specific case.

In the description of the present invention, "structure" and "mechanism" are understood broadly, and "structure" is understood to mean a part or component, and mechanism is understood to mean a component. The "light source output end" is a virtual concept, and refers to the end of the light source mechanism, which is close to the projection disk.

In the description of the present invention, the "preset eye axis" is a hypothetical virtual line, which can be understood as a parameter set during the development and assembly of a product; in the application process, the actual eye axis corresponding to the cornea is leaned against the preset eye axis, and the cornea and the preset eye axis are overlapped in an ideal state, and the preset eye axis is represented by a solid line in fig. 1 and is used for intuitively representing the relative position relation of the cornea, the projection disc and the annular light. The lines containing double-headed arrows in fig. 1, 2 and 6-8 are used to illustrate the movement direction of the first movement mechanism, and also correspond to the direction corresponding to the preset eye axis.

Example 1

As will be understood with reference to fig. 1. The embodiment provides a projection device based on cornea reflection, which realizes the function of projecting cornea and can be used for equipment for measuring cornea morphology or observing cornea information. The projection device based on cornea reflection is used for emitting annular light towards the cornea for a plurality of times, and the cornea reflects the annular light for each time one by one; the light reflected by the cornea can be further collected and analyzed to obtain the data of the cornea morphology, and can be amplified and used as an observation object; the components receiving the reflected light 60 are illustrated in dashed boxes in fig. 1 in order to understand the application scenario of a projection device based on corneal reflection.

The projection device based on cornea reflection includes a light source mechanism 10, a plate-like projection disk 20, and a first movement mechanism 30. The projection disk 20 is a light transmissive product. The light source mechanism 10 is located on a first side 201 of the projection disk 20, and in an operating state, the cornea of the object to be detected is located on a second side 202 of the projection disk 20, i.e., the light source mechanism 10 and the cornea are separated on opposite sides of the projection disk 20. The light source mechanism 10 outputs a hollow cone beam 102 with the preset eye axis 40 as an axis at the light output end 101, and projects annular light with the preset eye axis 40 as an axis on the first side 201 of the projection disk 20. As shown in fig. 1, the hollow cone beam 102 is surrounded by light having a uniform thickness, wherein the thickness of the hollow cone beam 102 represents the dimension d of the light in the normal direction of the optical path. The thickness of the hollow cone beam 102 varies, so that the width of the annular light on the projection disk 20 varies. The cornea on the second side 202 of the projection disk 20 receives the annular light to form reflected light 60, and the reflected light 60 can be further reflected after passing through the reflecting portion 203 of the projection disk 20, and the propagation direction is changed so as to be convenient to collect or observe; the reflecting portion 203 is a part of the projection disk 20, and the reflecting portion 203 is located at the center of the annular light and is coaxial with the annular light in terms of the relative position, that is, the reflecting portion 203 is centered on the preset eye axis 40. The first movement mechanism 30 contracts and expands the annular light by adjusting the relative positions of the projection disk 20 and the light output end 101 in the direction of the preset eye axis 40, and the "contracting and expanding" annular light can be understood as that the light source mechanism contracts and expands the radius of the annular light by taking the preset eye axis as the center of a circle, but the width of the annular light is not changed, and the projection device can acquire the reflected light 60 at different positions of the cornea in the process of contracting and expanding the annular light.

Before the cornea of the subject is detected or observed, the light source mechanism 10 is in an on state, the light source mechanism 10 and the projection disk 20 are positioned at the initial position, the subject is positioned at the second side 202 of the projection disk 20, and the subject adapts to the position of the projection disk 20 so that the visual axis thereof coincides with the preset eye axis 40. When the cornea of the tested person is tested, the relative positions of the projection disc 20 and the light output end 101 are adjusted through the first movement mechanism 30, for example, the projection disc 20 and the light output end 101 are gradually close to or gradually far away from each other in the direction of the preset eye axis 40, so that reflected light 60 emitted by the cornea under annular light with different sizes is obtained, and the reflected light 60 can be processed and used independently or can be used after superposition processing.

From the above description, it is clear that the Placido module consisting of the projection device based on corneal reflection and the existing Placido disk and illumination system is used to obtain corneal reflection information by projection onto the surface of the cornea. In contrast, prior art corneal topographers project onto a portion of the surface of the cornea at the same time to obtain incomplete corneal reflection information; the concept of the present disclosure is to obtain complete corneal reflection information based on partial surface projections to the cornea under a plurality of transients, wherein the complete corneal reflection information is formed by superimposing reflection information obtained from the plurality of transients.

More specifically, according to the present disclosure, the projection device based on corneal reflection may be dynamic when in an operating state, where each transient state has one ring light on the projection disc 20, the cornea outputs a set of reflected light 60 correspondingly, multiple sets of reflected light 60 (different transients are generated by the first motion mechanism 30) are generated under multiple transients, and the multiple sets of reflected light 60 can be superimposed to generate corresponding information such as cornea morphology, so that the projection device based on corneal reflection can at least implement the functions of Placido module in the prior art. In particular, in case the respective transient annular lights are set to coincide or overlap with each other in boundary (which is achieved by moving the first movement mechanism, described in detail below), the projection device based on corneal reflection can also acquire reflection information corresponding to the cornea position of the dark ring of the original Placido disc, so that the projection device acquires complete corneal surface morphology information.

The projection device based on corneal reflection has at least the following advantages over the existing Placido module:

(1) Since the projection disk 20 only needs to adopt a light-transmitting plate, such as a frosted glass plate or an acrylic plate, the existing mature product can be directly adopted, the shape of a conical cylinder body does not need to be processed, organic ink does not need to be sprayed to shield light, and the light source mechanism 10 and the first movement mechanism 30 do not need to develop special processing equipment and working procedures for processing, so that the manufacturing precision of the projection device based on cornea reflection is independent of the materials and the production process of the projection disk 20, the first movement mechanism 30 and the light source mechanism 10, and the problem that the manufacturing precision is difficult to improve due to the material and process limitation does not exist. In other words, the projection device based on corneal reflection fulfills the function of the existing Placido module at a lower manufacturing cost.

(2) The annular light projected to the cornea is generated by emitting a hollow cone beam 102 through the light source mechanism 10, only one beam of annular light is arranged on the projection disk 20 under each transient state, the cornea correspondingly outputs a group of reflected light 60, a plurality of groups of reflected light 60 can be obtained by capturing a plurality of transient states, and more comprehensive cornea morphological information can be obtained after the information of each group of reflected light 60 is overlapped; under the condition that the projection disk 20 and the light source mechanism 10 move relatively for the same distance, the number of groups of reflected light 60 obtained by reducing the annular light annular width and the interval time between two adjacent transients is more, and the effect of increasing the number of the annular rings of the conventional Placido disk is the same, namely, the detection precision is improved.

(3) When capturing several transients to obtain multiple sets of reflected light 60, adjusting the relative positions between the projection disk 20 and the light output end 101 can enable the radial dimensions of the annular light under adjacent transients to be partially overlapped or seamlessly connected, so that the reflected light 60 under several transients can obtain information of the whole cornea after being overlapped, and compared with intermittent data output by the existing Placido disk, the data of the projection device based on cornea reflection is continuous and more accurate.

Please understand with reference to fig. 2. In this embodiment, the light source mechanism 10 includes a light source module 103 and a shaping module 104, the light source module 103 is configured to emit parallel light, the shaping module 104 is configured to convert the parallel light into a hollow cone beam 102, and the light output end 101 is located on the shaping module 104. Specifically, the shaping module 104 is disposed between the light source module 103 and the projection disk 20, where the light source module 103 is configured to emit a beam of monochromatic collimated light, such as a visible light beam with a wavelength of 405nm, 532nm, 632.8nm, and the like, and the shaping module 104 receives the monochromatic collimated light and outputs the hollow cone beam 102, and projects the collimated light onto the projection disk 20 as annular light. In this embodiment, the thickness of the same hollow cone beam 102 is the same, and the radial position of the annular light on the projection disk 20 is changed but the annular width is unchanged in the process of adjusting the relative positions of the light output end 101 and the projection disk 20 in the eye axis direction.

In this embodiment, the light source module 103 is adopted to emit a light beam, and the shaping module 104 is utilized to shape the columnar light beam to obtain the hollow cone light beam 102, so that the diameter of the annular light projected onto the projection disk 20 is not dependent on the diameter of the parallel light beam emitted by the light source module 103, but can be realized only by the action of the first movement mechanism 30, and thus the light source module 103 with smaller volume can be adopted to project the annular light with larger diameter onto the projection disk 20.

In this embodiment, the shaping module 104 may include only a single axicon. The parallel light of the light source module is converted into a hollow cone beam 102 by this cone lens. In other embodiments, the shaping module 104 may employ a component or part other than a axicon, so long as it is capable of converting cylindrical monochromatic collimated light into annular light. As shown in fig. 10, which shows further embodiments from the left-hand view of fig. 1, the shaping module 104' alternatively comprises a turntable 71 and a number of axicon lenses 70. Each of the axicon lenses 70 is fixed at a different circumferential position of the turntable 71, and each of the axicon lenses 70 may have a different apex angle. The turntable 71 is rotated so that the axis of any one of the axicon lenses 70 coincides with the preset eye axis 40. When parallel light of the same diameter is input, the taper angles of the hollow cone beams 102 output by different cone lenses are different. The smaller the apex angle of the axicon 70, the larger the cone angle of the hollow cone beam, and the smaller the range of travel of the first movement mechanism 30. In another embodiment, the turntable 71 may be formed as an elongated chassis as shown in fig. 10, and the respective axicon lenses 70 are arranged alternately along the length direction of the chassis (see fig. 1, where the length direction of the chassis is a direction perpendicular to the paper surface). The desired axicon 70 can also be moved to a position aligned with the predetermined eye axis by moving the chassis back and forth.

In this embodiment, the diameter of the parallel light emitted by the light source module 103 is fixed, accordingly, since the shaping module 104 adopts the cone lens, the thickness of the hollow cone beam 102 output by the shaping module 104 is fixed, so that the width of the annular light projected on the projection disk 20 is fixed, that is, the widths of the lights projected to the cornea by the same projection device based on cornea reflection under different transients are consistent, and correspondingly, the difference between the inner diameter and the outer diameter of the annular light under each transient is constant.

In this embodiment, there is a linear motion in the direction of the preset eye axis 40 between the light output end 101 and the projection disk 20, and the linear motion is driven by the first motion mechanism 30, and there may be various specific implementation manners, for example: the first movement mechanism 30 drives the projection disk 20 to move relative to the light source mechanism 10 (as shown in fig. 1), and for example, the first movement mechanism 30 drives the light source module 103 and the shaping module 104 to move together relative to the projection disk 20, or the first movement mechanism 30 drives the shaping module 104 to move relative to the light source module 103 and the projection disk 20.

The radial dimension of the annular light on the projection disk 20 can be changed by displacing the light output end 101 and/or the projection disk 20 in the direction of the preset eye axis 40, in this embodiment, in order to detect or observe the information of each position of the cornea, the cone angle of the hollow cone beam 102 is controlled within 24 ° and the minimum annular light generated on the projection disk 20 has an inner diameter smaller than 4mm, correspondingly, the minimum distance between the light output end 101 and the projection disk 20 in the direction of the preset eye axis 40 is not greater than 9.4mm, and further, the maximum annular light generated on the projection disk 20 has an inner diameter not smaller than 28.8mm, correspondingly, the maximum distance between the light output end 101 and the projection disk 20 in the direction of the preset eye axis 40 is not less than 67.8mm, and in order to achieve the above purpose, the output of the first movement mechanism 30 on the preset eye axis 40 is 58.4mm.

In this embodiment, the first motion mechanism 30 is configured to output stepless linear motion, and can output continuous displacement within a stroke range thereof, and accordingly, the relative distance between the projection disk 20 and the light source mechanism 10 can be adjusted steplessly, so that when capturing reflected light 60 of the cornea in multiple transients, the radial relationship between two adjacent transient corresponding annular lights can be set arbitrarily, and after superposition, the radial relationship can be set locally in a coincident, seamless or spaced manner.

In this embodiment, the first movement mechanism 30 includes a driving module and a detection feedback module, the driving module is used to adjust the relative position of the light source mechanism 10 and/or the projection disk 20 in the direction of the preset eye axis 40, and any of the existing mechanisms capable of outputting linear movement, such as a screw-nut mechanism, a rack-and-pinion mechanism, a linear cam mechanism, a hydraulic cylinder, an air cylinder, and an electric cylinder, may be used. The drive module may be based on any one of electric drive, hydraulic drive and pneumatic drive. When the output end of the driving module is connected with the light source mechanism 10 or the projection disk 20, any one of fixed connection, detachable connection and movable connection can be adopted, so long as at least one of the light source mechanism 10 and the projection disk 20 can be driven to stably move towards the other in the direction of the preset eye axis 40. The driving module can output reciprocating motion along the direction of the preset eye axis 40, and can drive the light source mechanism 10 and the projection disk 20 to be close to each other and drive the light source mechanism and the projection disk to be far away from each other.

The detection feedback module is used for acquiring the relative displacement of the light source mechanism 10 and the projection disk 20; the detection feedback module can obtain the relative displacement by detecting the output quantity of the driving module, and can also obtain the relative displacement by detecting the distance between the light source mechanism 10 and the projection disk 20 and calculating. In this embodiment, the detection feedback module uses a linear grating scale to obtain the relative displacement.

The projection disk 20 only needs to adopt a plate capable of transmitting light, so that the precision requirement is low, the processing cost is low, and the acquisition is easy; the projection disk 20 may be a circular plate, a square plate, or other polygonal plate. The reflecting portion 203 is a part of the projection disk 20, and in this embodiment, the reflecting portion 203 has a solid structure and is integrally formed with other parts of the projection disk 20.

As shown in fig. 1 and 2, in this embodiment, the first surface 204 of the projection disk 20 facing the light source mechanism 10 and the second surface 205 facing away from the projection disk 20 are both planar. In other embodiments, as shown in FIG. 3, the first surface 204 may be spherical with a radius between 100mm and 300mm, or may be ellipsoidal, parabolic, hyperbolic, aspheric, or free-form.

In this embodiment, the first surface 204 and the second surface 205 of the projection disk 20 are frosted surfaces; in other embodiments, it is within the scope of the present invention to alternatively use a frosted surface for one of the first surface 204 and the second surface 205.

In this embodiment, the projection disk 20 is made of glass, and in other embodiments, the projection disk 20 may be made of transparent plastic, such as an acryl plate, as an alternative rear end.

Example 2

The present embodiment provides a projection apparatus based on cornea reflection, which is substantially the same as embodiment 1, except that the thickness d of the light beam output from the light source mechanism 10 of the present embodiment is adjustable.

In this embodiment, the diameter of the parallel light emitted by the light source module 103 is adjustable, correspondingly, as shown in fig. 4, the shaping module 104 adopts a conical lens, and the thickness of the hollow conical light beam 102 output by the shaping module changes along with the change of the diameter of the parallel light, and the two are positively correlated, so that the width of the annular light projected on the projection disk 20 is adjustable, and in the working condition with high precision requirement, the annular light with smaller annular width can be obtained by reducing the diameter of the parallel light emitted by the light source module 103, thereby improving the detection precision. Meanwhile, the projection device based on cornea reflection can be suitable for scenes with large detection precision spans.

Please understand with reference to fig. 5. In this embodiment, the light source module 103 includes a light source 1034 and a lens assembly, the light source 1034 is used for emitting monochromatic collimated light, such as laser light, and the lens assembly is used for adjusting the width of the monochromatic collimated light and emitting the collimated light with the adjusted width to the shaping module 104. Specifically, the lens assembly includes a first lens module 1031, a second lens module 1032, and a third lens module 1033. The first lens module 1031 is configured to receive monochromatic collimated light, the second lens module 1032 is configured to transmit light between the first lens module 1031 and the third lens module 1033, the third lens module 1033 is configured to output parallel light, and the position of the first lens module 1031 and/or the second lens module 1032 and/or the third lens module 1033 in the direction of the preset eye axis 40 is adjustable, so that the diameter of the parallel light output by the third lens module 1033 can be adjusted, fig. 5 is configured to illustrate three transients a, b and c of the light source module 103, wherein two dotted lines are configured to illustrate one movement track of the first lens module 1031 and the second lens module 1032, and the diameter of the output light beam of the third lens module 1033 is changed in three transients a, b and c (c has the smallest diameter and a has the largest diameter). In this embodiment, three lens modules are provided to adjust the diameter of the parallel light beam, and in other embodiments, the number of lens modules may be other integer numbers not less than 2, such as 2, 4 or 5.

In the present embodiment, each of the first lens module 1031, the second lens module 1032 and the third lens module 1033 has one lens, wherein each of the first lens module 1031 and the third lens module 1033 has a convex lens, and the second lens module 1032 has a concave lens. In other embodiments, the first lens module 1031 and/or the second lens module 1032 and/or the third lens module 1033 may alternatively be a plurality of lens assemblies.

In this embodiment, the light source module 103 further includes a second motion mechanism and a third motion mechanism, the second motion mechanism is connected to the first lens module 1031 and is used for driving the first lens module 1031 to move along the direction of the preset eye axis 40, and the third motion mechanism is connected to the second lens module 1032 and is used for driving the second lens module 1032 to move along the direction of the preset eye axis 40. The second movement mechanism and the third movement mechanism may employ existing mechanisms capable of outputting linear movement, for example, any one of a screw nut mechanism, a rack and pinion mechanism, a linear cam mechanism, a hydraulic cylinder, an air cylinder, and an electric cylinder. It should be noted that, in this embodiment, the second movement mechanism and the third movement mechanism may be based on electric driving, hydraulic driving or pneumatic driving, and may also be implemented by manual driving, for example, manually rotating a screw in a screw-nut mechanism, so as to control the linear movement of the first lens module 1031 or the second lens module 1032 connected to the nut.

The present embodiment adjusts the positions of the first lens module 1031 and the second lens module 1032 by using the second movement mechanism and the third movement mechanism, increasing the diameter variation range of the third lens output beam. In other embodiments, as an alternative, only the second movement mechanism or the third movement mechanism may be provided, that is, one position of the single lens assembly may be adjustable, and the other two may be fixedly provided, or the second movement mechanism and the third movement mechanism may be provided, and simultaneously, the fourth movement mechanism may be provided to control the third lens module 1033 to move along the preset eye axis 40, so as to further increase the diameter variation range of the output beam of the third lens.

In this embodiment, the light source module 103 adopts the above structure to emit the light beam with adjustable diameter, and in other embodiments, as an alternative means, the light source module 103 may directly use the existing continuous variable magnification beam expander.

Other parts of the projection device based on cornea reflection in this embodiment are the same as those in embodiment 1, and will not be described here again.

Example 3

With continued reference to fig. 1, this embodiment provides a cornea camera, which employs the projection apparatus based on cornea reflection provided in any of the above embodiments, and further includes an observation module having an incident end and an observation end, the reflected light 60 passing through the reflection portion 203 and then entering the incident end, the incident end further reflecting the reflected light 60 toward the observation end along a preset direction, and the observation end is used for observing the reflected light 60. In this embodiment, the preset direction is perpendicular to the direction in which the preset eye axis 40 is located, and in other embodiments, the preset direction and the preset eye axis 40 may be inclined, so that the reflected light 60 passing through the reflecting portion 203 does not interfere with the light source mechanism 10. When the projection device based on corneal reflection shown in fig. 1 is applied in this embodiment, the dashed box represents the observation module.

In this embodiment, the observation module changes the direction of the reflected light 60 and plays a role of amplifying, specifically, the observation module includes a beam splitter component and an amplifying mirror module, the incident beam splitter component is used to change the propagation direction of the reflected light 60, and the reflected light 60 is sequentially reflected by the beam splitter component and amplified by the amplifying mirror module, so as to be observed more clearly.

In the application process, the first movement mechanism can be enabled to be not operated, cornea information can be observed in a static mode, and the first movement mechanism can be enabled to be in electrodeless movement, so that morphological information of different positions of the cornea can be observed in a dynamic mode.

The film camera amplifies the morphological information of the local position of the cornea, in this embodiment, the amplified information can be directly observed from the observation end, and in other embodiments, other devices may be further installed at the observation end to further collect and/or analyze the amplified information.

Example 4

Please understand with reference to fig. 6. The present embodiment provides a corneal topography instrument for detecting a corneal topography. The corneal topographer includes the corneal reflection-based projection device provided in any of the embodiments above, and further includes an imaging module 50, the imaging module 50 for receiving the reflected light 60 and generating image information. The cornea topographic map further comprises an image processing module, the imaging module 50 transmits image information to the image processing module, and recording, analyzing and calculating the image information are realized by the image processing module; in specific implementation, the image processing module can be realized through an upper computer.

In this embodiment, the imaging module 50 has a first end 501 and a second end 502, wherein the first end 501 is configured as a beam splitter structure for receiving the reflected light 60 reflected by the cornea and transmitting the reflected light 60 to the second end 502, and the first end 501 to the second end 502 are arranged along a direction perpendicular to the preset eye axis 40. In this embodiment, the first end 501 of the beam splitter does not affect the projection of the hollow cone beam 102 to the projection disk 20, and the arrangement of the imaging module 50 along the direction perpendicular to the preset eye axis 40 reduces the space occupied by the imaging module 50 around the preset eye axis 40, and reduces the risk that the hollow cone beam 102 is blocked by the portion other than the first end 501 of the imaging module 50. In other embodiments, the first end 501 to the second end 502 may be arranged in a direction oblique to the preset eye axis 40 as an alternative.

In this embodiment, the imaging module 50 includes a beam splitter element 503, an imaging lens assembly 504 and an image sensor 505, the reflected light 60 is reflected into the imaging lens assembly 504 by the beam splitter element 503, the imaging lens assembly 504 focuses the light on the image sensor 505, the image sensor 505 is used for converting the light signal into an electrical signal, the electrical signal is processed to generate image information, and the image information is transmitted to the image processing module. The first end 501 includes a spectroscopic element 503 and the second end 502 includes an image sensor 505.

In this embodiment, the beam splitter element 503 adopts a filter (more specifically, a transflective filter) that is disposed at an angle of 45 ° with respect to the predetermined eye axis 40, so as to transmit the reflected light 60 from the cornea to the imaging lens group 504 along a direction perpendicular to the predetermined eye axis 40. The means for mounting the beam splitter element 503 may be made of a light transmissive material to prevent obstruction of the hollow cone beam 102. Since the imaging lens group 504 focuses the reflected light 60 to the image sensor 505, the positional relationship between the imaging lens group 504 and the image sensor 505 is related to the position of the cornea, which is fixed by default, and in this embodiment, the imaging module 50 has no displacement output in the direction of the preset eye axis 40, so that the imaging lens group 504 and the image sensor 505 are relatively stationary, and in other embodiments, if the imaging module 50 moves relatively to the cornea in the direction of the preset eye axis 40, the imaging lens group 504 and the image sensor 505 need to move relatively in the direction perpendicular to the preset eye axis 40. The imaging lens group 504 may be any one of a lens group formed by a single lens, a double cemented lens, an aspherical lens and any combination thereof, the image sensor may be a CCD or CMOS, and the imaging lens group 504 and the image sensor 505 may be implemented by using the prior art, which will not be described in detail.

As shown in fig. 6, in the present embodiment, the first movement mechanism 30 is connected to the projection disk 20, and is used for driving the projection disk 20 to move in the direction of the preset eye axis 40, and the light source mechanism 10, the imaging module 50 and the image processing module are fixedly arranged. Specifically, the output end of the first movement mechanism 30 is connected to the projection disk 20, and the two can be fixed by clamping, fastening, welding or other methods, so as to maintain the stability of the projection disk 20 during movement. In use, the light source mechanism 10 and the imaging module 50 are stationary, the first motion mechanism 30 is dynamic, and the projection disk 20 is driven to move relative to the light source mechanism 10 from far to near or from near to far by controlling the motion of the first motion mechanism 30, and during this time the imaging module 50 is controlled to image a number of transients.

The corneal topographer also includes a mounting enclosure (not shown) that encloses a mounting cavity in which the corneal reflection-based projection device and imaging module 50 are built. The mounting cover plays an integrated role in integrating the light source mechanism 10, the projection disk 20, the first movement mechanism 30 and the imaging module 50; the mounting cover also provides dust protection and prevents mechanical damage to the projection device and imaging module 50 from the external environment. The mounting cover is provided with a detection hole corresponding to the projection disk 20 in a direction to facilitate smooth propagation between the cornea outside the mounting cover and the projection disk 20 inside the mounting cover. In use, the eye is aligned with the detection aperture, annular light is incident on the cornea of the eye through the detection aperture, and reflected light 60 generated by the cornea is incident on the projection disk 20 after passing through the detection aperture.

The function and principle of the corneal topographer will be described in connection with its structure. The cornea topography instrument projects cornea, then obtains image information according to light information reflected by cornea, the image information can be used independently to represent local form information of cornea, and can also be used in a superposition way, after superposition, the form of cornea can be reflected more comprehensively, and even the real form of cornea can be reflected completely. The method comprises the steps that information obtained after superposition of image information is defined as a first result, the embodiment form of the first result is consistent with the embodiment form of information obtained by projecting cornea through an existing Placido module and imaging reflected light through a photographing system, but the precision of the first result can be flexibly adjusted by adjusting the interval between adjacent annular lights, and the precision of the first result can be improved by reducing the width of the annular lights under the condition that the width of the annular lights is adjustable, so that the cornea topographic map instrument of the embodiment can be applied to scenes with different precision requirements and working conditions requiring precision adjustment; in addition, the width of the annular light can be adjusted by controlling the diameter of the output beam of the light source module 103 and/or adjusting the cone angle of the hollow cone beam 102, the interval between adjacent annular lights can be adjusted by adjusting the output quantity of the first motion mechanism 30 and/or the shooting frequency of the imaging module 50, and the operation of adjusting the detection precision of the cornea topographic map instrument is simple and convenient, and the adjustment cost is low.

Taking the image information superposition as an example to further describe the working principle of the cornea topographic map instrument, in the process of the relative motion of the projection disk 20 and the light source mechanism 10, the imaging module 50 grabs a plurality of moments to image, and the adjacent two moments correspond to annular light superposition to possibly generate any one of three conditions of local superposition, seamless connection and existence interval, and when a plurality of image information are superposed, if noise occurs due to the local superposition of the annular light, one group of data in the superposition area can be removed. For a scene with intervals, provided that the radial interval between annular lights is the same as the radial interval between dark rings of the existing Placido disk, the detection effect of the cornea topographer is the same as that of the annular lights, but the cornea topographer is simple in structure and simple in manufacturing process.

Continuing to describe the working principle of the cornea topography instrument by taking the image information superposition as an example, setting different parameters can obtain different detection precision, for example, adjusting the initial distance between the light output end 101 and the projection disk 20 and/or adjusting the relative movement speed between the light output end 101 and the projection disk 20 and/or adjusting the shooting frequency of the imaging module 50, and can control the position relationship between the annular light corresponding to the n+1th shooting and the annular light corresponding to the n-th shooting of the imaging module 50, so as to obtain different detection precision. In the practical application process, a chip is set to control the first motion mechanism 30, the imaging module 50 and the light source mechanism 10, different modes can be written in the chip in advance, the detection precision corresponding to each mode is different, the operation parameter information of the first motion mechanism 30, the imaging module 50 and the light source mechanism 10 is preset in each mode, each mode corresponds to a key, and after the user selects the key with the required precision according to the detection requirement, the chip controls the first motion mechanism 30 and/or the imaging module 50 and/or the light source mechanism 10 to act according to the preset parameter information.

Continuing to describe the working principle of the cornea topography instrument by taking the use of overlapping of image information as an example, when the imaging module 50 performs imaging at equal intervals, the annular light corresponding to each image information is uniformly distributed, namely the widths of overlapping any two annular lights are consistent after overlapping, or the widths of the intervals of overlapping any two annular lights are consistent, or the overlapping of any two annular lights is not consistent and is gapless.

Example 5

The present embodiment provides a corneal topographer, which is different from embodiment 4 in that the object driven by the first movement mechanism 30 is specifically as follows:

as shown in fig. 7, in the present embodiment, the first movement mechanism 30 is configured to drive the shaping module 104 to move relative to the projection disk 20, where an output end of the first movement mechanism 30 is connected to the shaping module 104 to drive the shaping module to move along the preset eye axis 40, and the first movement mechanism and the shaping module can be fixed by clamping, fastening, welding, or other manners to maintain stability of the shaping module 104 during movement. Imaging module 50 is configured to be relatively stationary with respect to projection disk 20 while imaging module 50, projection disk 20 and the cornea are relatively stationary during use, and accordingly, the relative positions of imaging lens assembly 504 and image sensor 505 are unchanged. The imaging module 50 is secured to the mounting cup by clamping, fastening, welding, etc. the projection plate 20.

In this embodiment, the light source module 103 is disposed to be relatively stationary with the projection disk 20, and the light source module 103 is fixed on the mounting cover by clamping, fastening, welding, etc., and as an alternative, it is also within the scope of the present invention that the light source module 103 is disposed to be relatively stationary with the shaping module 104.

In order to obtain a more complete and precise cornea shape, the smaller the minimum annular light inner diameter of the shaping module 104 projected on the projection disk 20 is, the better, so in this embodiment, a through hole 5031 for the shaping module 104 to pass through is provided on the spectroscope element 503, and when the first movement mechanism 30 drives the shaping module 104 to move, the shaping module 104 can partially or entirely pass through the through hole 5031 to project the annular light with the smaller inner diameter on the projection disk, so as to obtain a more complete and precise cornea shape. The size of the through hole 5031 is sufficient as long as the above function is satisfied, and the aperture of the through hole 5031 is set within 4mm in this embodiment.

In use, the projection disk 20 and the imaging module 50 are stationary, and the shaping module 104 is driven by the first movement mechanism 30 to move from far to near or from near to far relative to the projection disk 20, during which the imaging module 50 performs imaging.

It should be noted that, the relative sizes of the shaping module 104 and the light source module 103 illustrated in fig. 1 and fig. 7 are different, but are not contradictory, and fig. 1 and fig. 7 are used for illustration so as to facilitate understanding of the present invention in conjunction with text information, and the sizes of the various parts in the figures do not represent the sizes in practical use, and even for the same component, the sizes may also be different if the models selected in practical use are different.

Other parts of the corneal topographer in this embodiment are the same as those in embodiment 4, and will not be described in detail here.

Example 6

The present embodiment provides a corneal topographer, which is different from embodiment 4 in terms of the object driven by the first movement mechanism 30 and the structural change caused by the difference in the driving object, specifically, as follows:

as shown in fig. 8, the output end of the first movement mechanism 30 is connected to the shaping module 104 and the imaging module 50, and is used for driving the shaping module 104 and the imaging module 50 to move together in the preset eye axis 40 direction relative to the projection disk 20. While an imaging lens group 504 within the imaging module 50 is arranged to move between the spectroscopic element 503 and the image sensor 505 to focus light on the image sensor 505. In this embodiment, the light source module 103 is disposed at a relatively stationary position with respect to the shaping module 104, and alternatively, the light source module 103 may be disposed at a relatively stationary position with respect to the projection disk 20.

In this embodiment, the imaging module 50 further includes a fifth movement mechanism, an output end of the fifth movement mechanism is connected to the imaging lens group 504, and is used to drive the imaging lens group 504 to reciprocate between the beam splitter element 503 and the image sensor 505, so as to focus light on the image sensor 505; the solid double arrow lines in fig. 8 are provided above and below to illustrate that the imaging lens group 504 is not dynamic during use. The fifth movement mechanism may employ an existing mechanism capable of outputting linear movement, for example, any one of a screw nut mechanism, a linear cam mechanism, a rack and pinion mechanism, a hydraulic cylinder, an air cylinder, and an electric cylinder. The fifth movement mechanism and the first movement mechanism 30 may be provided in a linked manner, and the fifth movement mechanism automatically operates according to the output of the first movement mechanism 30.

In use, the projection disk 20 is in a static state, the shaping module 104 and the imaging module 50 are driven to move together towards a direction approaching or separating from the projection disk 20 by the first movement mechanism 30, and the imaging lens set 504 is driven to move by the fifth movement mechanism, so that light is always focused on the image sensor 505, and meanwhile, the imaging module 50 is controlled to perform imaging.

Example 7

As will be understood with reference to fig. 9. This embodiment provides a method of corneal topography detection using any of the corneal topography instruments described above for detecting a cornea located on the second side 202 of the projection disc 20, the method comprising the steps of:

controlling the first movement mechanism 30 to drive the light output end 101 and the projection disk 20 to relatively move for a first distance in the direction of the preset eye axis 40, and controlling the imaging module 50 to shoot and obtain a plurality of image information;

and superposing the image information to obtain information which is the first result.

In this embodiment, the axis of the cornea located on the second side 202 is coincident with the preset axis before detection, that is, the cornea is located, and the specific locating mode may be to adapt to the position of the projection disk 20 by moving the face of the person, or may be to set a locating portion on the mounting cover, to initially locate the face by using the locating portion, and then fine-tune the face based on the locating portion to adapt to the position of the projection disk 20.

In this embodiment, in the step of controlling the first movement mechanism 30 to drive the light output end 101 and the projection disk 20 to move relatively by a first distance in the direction of the preset eye axis 40, the imaging module 50 is controlled to capture and obtain a plurality of image information:

The first motion mechanism 30 is configured to output an electrodeless motion (forward and backward rectilinear motion along a preset eye axis), and control the first motion mechanism 30 to drive the projection disk 20 to move at a uniform speed for a first distance relative to the light output end 101, where the imaging module 50 shoots at a preset frequency, so that annular lights corresponding to each image information are uniformly distributed after being superimposed; the initial distance between the light output end 101 and the projection disk 20 and/or the relative movement speed between the light output end 101 and the projection disk 20 and/or the shooting frequency of the imaging module 50 are/is adjusted so that the outer diameter of the annular light corresponding to the (n+1) th shooting of the imaging module 50 is equal to the inner diameter of the annular light corresponding to the (n) th shooting, and thus the first result is continuous and non-overlapping. Indeed, in other methods, the outer diameter of the annular light corresponding to the n+1th shot of the imaging module 50 may be larger than the inner diameter of the annular light corresponding to the n-th shot.

Example 8

This embodiment provides a method of corneal topography detection using any of the corneal topography instruments described above for detecting a cornea located on the second side 202 of the projection disc 20, the method comprising the steps of:

In this embodiment, the axis of the cornea on the second side 202 is coincident with the predetermined axis, i.e., positioned on the cornea, prior to the examination, in the same manner as described in embodiment 7.

the first motion mechanism 30 is used for outputting an electrodeless motion, the first motion mechanism 30 drives the projection disk 20 and the light output end 101 to relatively move for a plurality of times to reach a relative motion amount of a first distance, and the imaging module 50 is controlled to shoot at a gap between the two relative motions to form graphic information. The amount of movement of each relative movement of the projection disk 20 and the light output end 101 is the same, the initial distance between the light output end 101 and the projection disk 20 is adjusted, and/or the relative movement speed between the light output end 101 and the projection disk 20 is adjusted, and/or the shooting frequency of the imaging module 50 is adjusted, so that the outer diameter of the annular light corresponding to the (n+1) th shooting of the imaging module 50 is equal to the inner diameter of the annular light corresponding to the (n) th shooting, and the first result is continuous and non-overlapping. Indeed, in other methods, the outer diameter of the annular light corresponding to the n+1th shot of the imaging module 50 may be larger than the inner diameter of the annular light corresponding to the n-th shot.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. A projection device based on cornea reflection, which is characterized by comprising a light source mechanism, a platy projection disk and a first movement mechanism, wherein the light source mechanism is provided with a light output end, the light source mechanism is used for outputting a hollow cone beam taking a preset eye axis as an axis at the light output end and projecting annular light on a first side of the projection disk, and the first movement mechanism is used for shrinking and expanding the annular light by adjusting the relative position between the light output end and the projection disk in the preset eye axis direction; a cornea positioned on the second side of the projection disk receives the annular light to form reflected light, and the reflected light can be changed in light path after passing through the reflecting part of the projection disk; the reflecting portion is located at the center of the annular light and is coaxial with the annular light.

2. The corneal reflection-based projection device of claim 1, wherein the light source mechanism comprises a light source module capable of emitting parallel light and a shaping module for converting the parallel light into a hollow cone beam.

3. The projection device of claim 2, wherein the diameter of the parallel light emitted by the light source module is adjustable, and the thickness of the hollow cone beam output by the shaping module varies with the diameter of the parallel light.

4. The cornea reflection-based projection apparatus of claim 2, wherein the light source module includes a light source, a first lens module for receiving parallel light of the light source, a second lens module for transmitting light between the first lens module and the third lens module, and a third lens module for outputting parallel light, and a position of the first lens module and/or the second lens module and/or the third lens module is adjustable in the preset eye axis direction.

5. The cornea reflection-based projection apparatus of claim 4, wherein the light source module further comprises a second movement mechanism for driving the first lens module to move in the direction of the preset eye axis and/or a third movement mechanism for driving the second lens module to move in the direction of the preset eye axis.

6. The cornea reflection-based projection apparatus of claim 2, wherein the light source module is a continuous variable magnification beam expander.

7. The corneal reflection-based projection device of claim 2,

the shaping module comprises a conical lens opposite to the light source module, and parallel light of the light source module is converted into a hollow conical light beam through the conical lens; or,

8. The corneal reflection-based projection device of claim 2, wherein the first movement mechanism drives the projection disk to move relative to the light source mechanism, or wherein the first movement mechanism drives the light source module and the shaping module together to move relative to the projection disk, or wherein the first movement mechanism drives the shaping module to move relative to the light source module and the projection disk.

9. The corneal reflection-based projection device of claim 1, wherein the first motion mechanism comprises a drive module for adjusting the relative positions of the light source mechanism and the projection disk in the direction of the preset eye axis and a detection feedback module for acquiring the relative displacement of the light source mechanism and the projection disk; the detection feedback module comprises a linear grating ruler.

10. The corneal reflection-based projection device of claim 1,

the first surface of the projection disk facing the light source mechanism is a plane, a sphere, an ellipsoid, a paraboloid, a hyperboloid, an aspheric surface or a free-form surface; wherein, the spherical radius is between 100mm and 300 mm;

11. The corneal reflection-based projection device of claim 1,

at least one of a first surface of the projection disk facing the light source mechanism and a second surface of the projection disk facing away from the light source mechanism is a frosted surface;

the projection disk is made of glass or plastic.

12. A cornea imager comprising the projection device based on cornea reflection according to any one of claims 1 to 11 and an observation module, wherein the observation module comprises an incident end and an observation end, the reflected light enters the incident end after passing through the reflection part, and propagates to the observation end further along a preset direction under the action of the incident end, and the preset direction is inclined or vertical relative to the direction of the preset eye axis.

13. A corneal topographer, comprising:

The corneal reflection-based projection device of any one of claims 1-11;

and the imaging module is used for receiving the reflected light and generating image information.

14. The corneal topographer of claim 13, wherein the imaging module comprises a first end and a second end, wherein the first end is configured as a spectroscopic structure for receiving the reflected light and propagating the reflected light toward the second end, the first end to the second end being disposed in a direction perpendicular to the pre-determined eye axis.

15. The corneal topographer of claim 13, wherein the imaging module comprises a beam splitter element, an imaging lens group, and an image sensor, the reflected light being reflected by the beam splitter element into the imaging lens group, the imaging lens group focusing light on the image sensor.

16. The corneal topographer of claim 15, wherein the light source mechanism comprises a light source module and a shaping module for converting parallel light emitted by the light source module into the hollow cone beam;

the first movement mechanism is used for driving the shaping module to move relative to the light source module and the projection disc, the imaging module and the shaping module are arranged to be relatively static, and the spectroscope element is provided with a through hole for the shaping module to pass through.

17. The corneal topographer of claim 15, wherein the light source mechanism comprises a light source module and a shaping module for converting parallel light emitted by the light source module into the hollow cone beam;

the first movement mechanism is used for driving the shaping module and the imaging module to move together relative to the light source module and the projection disc, the spectroscope element and the image sensor are arranged to be static relative to the shaping module, and the imaging lens group is arranged to move between the spectroscope element and the image sensor so as to focus light rays on the image sensor.

18. The corneal topographer of claim 13, wherein the corneal topographer comprises a lens,

the cornea topography instrument further comprises an image processing module for calculating and/or analyzing the image information;

19. A method of corneal topography detection, wherein the method is implemented using a corneal topography instrument according to any one of claims 13-18 for detecting a cornea located on a second side of the projection disc, the method comprising the steps of:

Controlling the first movement mechanism to drive the light output end of the light source mechanism and the projection disk to move relatively for a first distance in the preset eye axis direction, and controlling the imaging module to shoot and acquire a plurality of image information during the first movement mechanism;

and superposing the image information.

20. The method for detecting corneal topography according to claim 19, wherein said controlling said first movement mechanism drives said light output end and said projection disk to move relatively in said predetermined eye axis direction by a first distance, and wherein said imaging module is controlled to take a photograph and obtain a plurality of image information:

21. The method for detecting corneal topography according to claim 19, wherein said controlling said first movement mechanism drives said light output end and said projection disk to move relatively in said predetermined eye axis direction by a first distance, and wherein said imaging module is controlled to take a photograph and obtain a plurality of image information:

22. The method of claim 20 or 21, wherein driving the light output end and the projection disk to move relatively in the direction of the preset eye axis by the first movement mechanism for a first distance, and controlling the imaging module to take images and obtain a plurality of image information during the first distance further comprises: