CN115414001A

CN115414001A - Projection device based on corneal reflection, corneal photography instrument, corneal topography instrument and detection method thereof

Info

Publication number: CN115414001A
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: 2022-12-02
Anticipated expiration: 2042-08-15
Also published as: CN115414001B; WO2024037035A1

Abstract

The invention discloses a projection device, a corneal photography instrument, a corneal topographer and a detection method thereof based on corneal reflection, and belongs to the field of ophthalmology. The device comprises a light source mechanism, a plate-shaped projection disc and a first movement mechanism, wherein the light source mechanism is provided with a light ray 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 ray output end and projecting annular light on a first side of the projection disc, and the first movement mechanism contracts and magnifies the annular light by adjusting the relative positions of the light ray output end and the projection disc in the direction of the preset eye axis; the cornea on the second side of the projection disc receives the annular light to form reflected light, and the reflected light penetrates through the reflection part of the projection disc, and the reflection part is positioned in the center of the annular light and is coaxial with the annular light. In the invention, the projection device based on the corneal reflection realizes the function of the conventional Placido module with lower manufacturing cost.

Description

Projection device based on corneal reflection, corneal photography instrument, corneal topography instrument and detection method thereof

Technical Field

The invention relates to the field of ophthalmology, in particular to a projection device, a corneal photography instrument, a corneal topographer and a detection method thereof based on corneal reflection.

Background

Corneal topography is a topography of the cornea that is recorded and analyzed by various methods as a local topography, which is called a corneal topography because of the apparent topography of topographic surface relief. The corneal topography can reflect the morphological change of the corneal surface, the curvature and astigmatism types of the cornea of the examiner can be judged from the topography of the anterior and posterior surfaces of the cornea, and even whether the keratoconus is possible to appear or not can be found in advance.

The corneal topographer is a device for detecting corneal topography, and is widely applied to a Placido disc-based corneal topographer. The Placido plate is made of transparent materials and comprises a conical cylinder structure with a small hole in the middle, a plurality of alternate concentric rings (a bright ring and a dark ring respectively) 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 topographic map instrument based on the Placido disc further comprises an illuminating system, a camera system and an image processing system, the cornea topographic map instrument projects concentric circular ring images on the Placido disc 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 topographic map, specifically, the illuminating system irradiates the Placido disc, the light penetrates through a bright ring to enter the cornea, the light reflected by the cornea penetrates through a small hole in the center of the Placido disc 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 topographic map.

In clinical examination of the cornea, besides analyzing the corneal condition of the examiner by acquiring a corneal topography, some information of the examiner's cornea can be acquired by observing the corneal morphology. Chinese utility model patent publication No. CN207136833U, published 3/27/2018, discloses a hand-held Placido keratoscope, which projects light to the cornea of the observed person by using a Placido plate, and the light reflected by the cornea of the observed person is captured by the observed person after being amplified by an objective lens and an eyepiece as a basis for judging astigmatic information.

As can be seen from the above, the conventional Placido-disc-based corneal topographer and keratographer both include a Placido module formed by a Placido disc and an illumination system, the Placido module corresponds to a projection device for projecting light to the cornea, and the Placido module captures information reflected by the cornea by projecting annular light to the cornea, but the Placido module has the following defects:

(1) The Placido plate needs to be provided with the bright rings and the dark rings 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; in particular, a Placido disc applied to a cornea map instrument is irregular in shape, and the bright ring and the dark ring are arranged on the inner surface of the conical cylinder body, so that the requirements of manufacturing precision 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 high-precision dark rings on a Placido disc is complex, so that the machining cost of Placido modules is high;

(3) The width of the ring on the Placido disc directly influences the detection precision of the corneal topographer and the observation result of the corneal photogrammeter, 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 the aspects of technical research and development and the configuration of a matched processing technology;

(4) The precision of the Placido module is not adjustable, when the device is specifically applied, a fixed Placido disc is arranged on the corneal topography instrument and the corneal photographer, the parameters of a light ring and a dark ring of the Placido disc are not adjustable, so that the detection precision of the corneal topography instrument and the observation precision of the corneal photographer are also not adjustable, correspondingly, the low-precision corneal topography instrument cannot adapt to the working condition with high requirement on the precision of the corneal topography, and the low-precision corneal photographer has the risk of misdiagnosis;

(5) The information obtained by the cornea topographer and the keratograph is only the cornea information at the position corresponding to the bright ring of Placido, but not the continuous information representing the surface morphology of each position of the cornea, subject to the working principle of Placido plates. The corneal topographer needs to fit the information of these discontinuities through complex image processing algorithms to obtain a topographical map. Therefore, the data output by the corneal topographer and the keratographer do not fully and truly represent the actual situation at all locations of the cornea.

Disclosure of Invention

An object of the present invention is to provide a projection device, a corneal imager, a corneal topographer, and a detection method thereof based on corneal reflection, which output information of corneal reflection by projecting annular light to a cornea, and which are an alternative to a Placido plate and a Placido module composed of an illumination system in the related art, and which have the advantages of independent manufacturing accuracy from materials, processing techniques, and processing equipment, and low manufacturing cost.

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

A projection device based on corneal reflection comprises a light source mechanism, a plate-shaped projection disc and a first movement mechanism, wherein the light source mechanism comprises a light ray 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 ray output end and projecting annular light on a first side of the projection disc, and the first movement mechanism is used for shrinking and enlarging the annular light by adjusting the relative position between the light ray output end and the projection disc in the direction of the preset eye axis; the cornea on the second side of the projection disc forms reflected light after receiving the annular light, and the reflected light can pass through the reflecting part of the projection disc and then is changed in optical path; the reflection part is positioned in the center of the annular light and is coaxial with the annular light.

Optionally, the light source mechanism includes a light source module and a shaping module, the light source module can emit parallel light, and the shaping module is used for converting the parallel light into a 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 with the change of the diameter of the parallel light.

Optionally, the light source module includes a light source, a first lens module, a second lens module, and a third lens module, the first lens module is configured to receive parallel light of the light source, the second lens module is configured to transmit light between the first lens module and the third lens module, the third lens module is configured to output 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.

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

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

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

the shaping module comprises a mounting piece and a plurality of cone lenses, the cone lenses are mounted on the mounting piece, and the mounting piece is used for adjusting the positions of the cone lenses so that the axis of any one cone 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 movement mechanism includes a driving module and a detection feedback module, the driving module is configured to adjust a relative position of the light source mechanism and the projection disk in the preset eye axis direction, and the detection feedback module is configured to obtain a relative displacement between the light source mechanism and the projection disk; the detection feedback module comprises a linear grating ruler.

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

and a second surface of the projection disc, which is far away from the light source mechanism, is a plane.

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

the projection disk is made of glass or plastic.

A corneal photocopy device comprises the projection device based on corneal reflection and an observation module as described above, wherein the observation module comprises an incident end and an observation end, the reflected light passes through the reflection part and then enters the incident end, and further propagates to the observation end along a preset direction under the action of the incident end, and the preset direction is inclined or vertical to the direction of the preset eye axis.

A corneal topographer comprising:

a corneal reflection based projection device as claimed in 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 through the beam splitter element, and the imaging lens group focuses light on the image sensor.

Optionally, the first movement mechanism is configured to drive the shaping module to move relative to the light source module and the projection disk, the imaging module and the shaping module are set to be relatively stationary, and the beam splitter element is provided with a through hole through which the light output end passes.

Optionally, the first moving mechanism is configured to drive the shaping module and the imaging module to move together 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 topographer further comprises an image processing module for calculating and/or analyzing the image information;

the cornea topographic map instrument further comprises an installation cover, the installation cover encloses an installation cavity, and the projection device based on cornea reflection and the imaging module are arranged in the installation cavity.

A corneal topography inspection method implemented using a corneal topographer as claimed in any preceding claim for inspecting 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 ray output end and the projection disc to relatively move for a first distance in the preset eye axis direction, and controlling the imaging module to shoot and obtain a plurality of image information;

and superposing the image information.

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

the first movement mechanism is used for outputting stepless movement, and controls the first movement mechanism to drive the projection disc to move at a constant speed for a first distance relative to the light ray output end, and the imaging module shoots according to a preset frequency.

the projection disc and the light ray 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 ray output end is the same, and the imaging module is controlled to shoot in the gap of 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 the step of controlling the imaging module to shoot and obtain a plurality of image information further includes:

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 a light-transmitting plate, such as a frosted glass plate, the existing mature product can be directly adopted, the shape of a conical cylinder does not need to be processed, the organic ink does not need to be sprayed for shading, and the light source mechanism and the first motion mechanism do not need to be processed by researching and developing special processing equipment and working procedures, so that the manufacturing precision of the projection device based on corneal reflection does not depend on the materials and the production process of the projection disc, the first motion mechanism and the light source mechanism, and the problem that the manufacturing precision is difficult to improve due to the limitation of materials and processes does not exist.

(2) Annular light projected to the cornea is generated by emitting a hollow cone beam through a light source mechanism, only one annular light beam is emitted on each transient lower projection disc, the cornea correspondingly outputs one group of reflected light, a plurality of transients are captured to obtain a plurality of groups of reflected light, and the information of each group of reflected light is superposed to obtain comprehensive and accurate corneal shape information; under the condition that the projection disc and the light source mechanism move relatively for the same distance, the ring width of the annular light is reduced, the number of groups of reflected light obtained by reducing the interval duration between two adjacent transients is more, the effect of increasing the ring number of the existing Placido disc is the same, namely, the detection precision is improved, but the ring width of the annular light is reduced, the interval duration between two adjacent transients is reduced, a complex process is not needed, and the method is easy to realize.

(3) When capturing a plurality of transients to obtain a plurality of sets of reflected light, adjusting the relative position between the projection disc and the light output end, enabling the radial dimension of the annular light under adjacent transients to be partially overlapped or seamlessly connected, so that the reflected light under a plurality of transients can be superposed to obtain the information of the whole cornea, and compared with the discontinuous data output by the existing Placido disc, the data of the projection device based on the corneal reflection is continuous and more accurate.

Drawings

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

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

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

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

fig. 4 is a comparison diagram of the output light beam of the shaping module in embodiment 2 of the present invention, which is used to show that the thickness of the output hollow cone light beam changes when the diameter of the parallel light beam received by the shaping module changes;

fig. 5 is a structural comparison diagram of the light source module of embodiment 2 of the present invention in three transient states;

FIG. 6 is a schematic structural view of a corneal topographer in accordance with example 4 of the present invention;

FIG. 7 is a schematic structural view of a corneal topographer in accordance with example 5 of the present invention;

FIG. 8 is a schematic structural view of a corneal topographer in accordance with example 6 of the present invention;

FIG. 9 is a flowchart of a corneal topography detection method according to example 7 of the present invention;

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

Reference numerals

Light source mechanism 10

Light ray 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 part 203

First surface 204

Second surface 205

First movement mechanism 30

Preset eye axis 40

Imaging module 50

First end 501

Second end 502

Beam splitting mirror 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 otherwise defined, technical or scientific terms used in the present specification and claims should have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

In the description of the present invention, it is to be understood that the terms "inside", "outside", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

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

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected 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 through specific situations.

In the description of the present invention, "structure" and "mechanism" are to be interpreted broadly, with "structure" being understood to mean a part or an element, and with "mechanism" being understood to mean an element. The 'light source output end' is a virtual concept and refers to one end of a light source mechanism close to a projection disc.

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

Example 1

This is understood with reference to fig. 1. The present embodiment provides a projection apparatus based on corneal reflection, which realizes a function of projecting a cornea and can be used for a device for measuring a corneal morphology or observing corneal information. The projection device based on corneal reflection is used for emitting annular light towards the cornea for multiple 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 form, and can also be amplified and used as an observation object; the components that receive the reflected light 60 are illustrated in fig. 1 in a dashed box in order to understand the application scenario of the projection device based on corneal reflection.

The projection apparatus based on corneal reflection includes a light source mechanism 10, a plate-shaped projection plate 20, and a first movement mechanism 30. The projection panel 20 is a product capable of transmitting light. The light source mechanism 10 is located on a first side 201 of the projection disk 20, and the cornea of the detection target object is located on a second side 202 of the projection disk 20 in an operating state, that is, the light source mechanism 10 and the cornea are respectively arranged on opposite sides of the projection disk 20. One end of the light source mechanism 10 close to the projection disk 20 is a light output end 101, and 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 a first side 201 of the projection disk 20. As shown in FIG. 1, the hollow cone beam 102 is surrounded by light of 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 width of the ring light on the projection disk 20 varies with the thickness of the hollow cone beam 102. 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 part 203 of the projection disk 20 to change the propagation direction so as to be collected or observed; the reflection portion 203 is a part of the projection disk 20, and the reflection portion 203 is located at the center of the annular light and coaxial with the annular light in terms of relative position, that is, the reflection portion 203 takes the preset eye axis 40 as an axis. The first movement mechanism 30 adjusts the relative position of the projection disc 20 and the light output end 101 in the direction of the preset eye axis 40 to zoom in and out the annular light, which can be understood as the radius of the annular light that is zoomed out and enlarged by the light source mechanism with the preset eye axis as the center of a circle, but does not change the width of the annular light, and the projection device can obtain the reflected light 60 of different positions of the cornea during the process of zooming in and out 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 located at the initial position, the subject is located 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 of the subject coincides with the preset eye axis 40. When the cornea of the subject is detected, the relative positions of the projection disc 20 and the light output end 101 are adjusted by the first motion mechanism 30, for example, the projection disc 20 and the light output end 101 are gradually close to or away from each other in the direction of the preset eye axis 40, so as to obtain the reflected light 60 emitted by the cornea under the annular light with different sizes, and the reflected light 60 can be processed and used independently or can be used after being processed in an overlapping manner.

From the above description, the Placido module composed of the projection device based on corneal reflection and the existing Placido disc and illumination system obtains the corneal reflection information by projecting to the surface of the cornea. In contrast, the corneal topographer of the prior art projects a portion of the surface of the cornea downward at the same time to obtain incomplete corneal reflection information; the idea of the present disclosure is to obtain complete corneal reflection information based on partial surface projection of a plurality of transients onto the cornea, wherein the complete corneal reflection information is formed by superimposing a plurality of transient derived reflection information.

More specifically, according to the present disclosure, the projection device based on corneal reflection may be dynamic when in an operating state, each transient state lower projection plate 20 has a ring light, the cornea correspondingly outputs a group of reflected lights 60, multiple transient states generate multiple groups of reflected lights 60 (different transient states are adjusted and generated by the first movement mechanism 30), and the multiple groups of reflected lights 60 can generate corresponding information such as the morphology of the cornea after being superimposed, so that the projection device based on corneal reflection can at least realize the function of Placido module in the prior art. In particular, in the case that the ring lights of the respective transients are set to overlap or overlap each other in boundary (which can be realized by moving the first motion mechanism, as described in detail below), the projection device based on corneal reflection can also acquire reflection information corresponding to the corneal position of the dark ring of the original Placido plate, so that the projection device can acquire 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 be a transparent plate, such as a frosted glass plate or acrylic plate, existing mature products can be directly adopted, the shape of a conical cylinder does not need to be processed, organic ink does not need to be sprayed for shading, and the light source mechanism 10 and the first movement mechanism 30 do not need to be processed by researching and developing special processing equipment and working procedures, so that the manufacturing precision of the projection device based on corneal reflection does not depend on the materials and production processes 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 limitations of materials and processes does not exist. In other words, the projection device based on corneal reflection realizes 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 annular light beam is on the projection disc 20 in each transient state, the cornea correspondingly outputs one group of reflected light 60, a plurality of transient states are captured to obtain a plurality of groups of reflected light 60, and more comprehensive corneal morphological information can be obtained after the information of each group of reflected light 60 is superposed; under the condition that the projection disk 20 and the light source mechanism 10 relatively move for the same distance, the ring width of the annular light is reduced, the number of groups of the reflected light 60 obtained by reducing the interval time between two adjacent transients is more, and the effect of increasing the ring number of the existing Placido disk is the same, namely, the detection precision is improved.

(3) When capturing a plurality of transients to obtain a plurality of sets of reflected light 60, adjusting the relative position between the projection disk 20 and the light output end 101 can enable the radial dimension of the ring light in adjacent transients to be partially overlapped or seamlessly connected, so that the reflected light 60 in a plurality of transients can be overlapped to obtain the information of the whole cornea, and compared with the discontinuous data output by the existing Placido disk, the data of the projection device based on the corneal reflection is continuous and more accurate.

Please refer to fig. 2 for understanding. 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 used for emitting parallel light, the shaping module 104 is used for converting 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 sets up between light source module 103 and projection dish 20, and light source module 103 is used for sending a bundle of monochromatic collimated light, for example the wavelength is at visible light beam such as 405nm, 532nm, 632.8nm, and shaping module 104 receives monochromatic collimated light and outputs hollow cone beam 102, throws and embodies annular light on projection dish 20. In this embodiment, the thickness of the same hollow cone beam 102 is the same, and during the process of adjusting the relative position of the light output end 101 and the projection disk 20 in the eye axis direction, the radial position of the annular light on the projection disk 20 changes, but the annular width does not change.

In this embodiment, the light source module 103 emits a light beam, and the shaping module 104 shapes the cylindrical light beam to obtain the hollow cone light beam 102, 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 only by the action of the first movement mechanism 30, so that the annular light with a larger diameter can be projected onto the projection disk 20 by using the light source module 103 with a smaller volume.

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 through the cone lens. Other embodiments may use components or parts other than axicons for the reshaping module 104, as long as it can convert the cylindrical monochromatic collimated light into annular light. As shown in fig. 10, which shows further embodiments from the left side of fig. 1, the reshaping module 104' comprises as an alternative a turret 71 and several axicons 70. Each axicon lens 70 is fixed at a different circumferential position on a turret 71 and each axicon lens 70 may have a different apex angle. The turret 71 is rotated so that the axis of any one of the axicons 70 coincides with the preset eye axis 40. When parallel light with the same diameter is input, the cone angle of the hollow cone beam 102 output by different cone lenses is different. The smaller the vertex angle of the axicon lens 70 is, the larger the cone angle of the hollow cone beam is, and the smaller the stroke range of the first movement mechanism 30 is. In another embodiment, the turntable 71 may be formed as an elongated chassis as shown in fig. 10, and the conical lenses 70 are alternately arranged along the length direction of the chassis (see fig. 1, the length direction of the chassis is a direction perpendicular to the paper surface). The desired axicon lens 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 from the light source module 103 is fixed, and accordingly, since the shaping module 104 employs a cone lens, the thickness of the hollow cone beam 102 output by the shaping module 104 is fixed, so that the width of the ring light projected on the projection disk 20 is fixed, that is, the width of the light projected to the cornea by the same projection device based on corneal reflection is consistent in different transient states, and correspondingly, the difference between the inner and outer diameters of the ring light is constant in each transient state.

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

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 °, the inner diameter of the smallest annular light generated on the projection disk 20 is smaller than 4mm, accordingly, 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 larger than 9.4mm, further, the inner diameter of the largest annular light generated on the projection disk 20 is not smaller than 28.8mm, accordingly, 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 smaller than 67.8mm, and for this purpose, the output quantity of the first movement mechanism 30 on the preset eye axis 40 is 58.4mm.

In this embodiment, the first movement mechanism 30 is configured to output an infinite linear movement, and can output a continuous displacement within a stroke range thereof, accordingly, the relative distance between the projection disk 20 and the light source mechanism 10 can be adjusted in an infinite manner, and the two can be positioned at any position, so that when capturing the reflected light 60 of the cornea under multiple transients, the radial relationship between the ring lights corresponding to two adjacent transients can be arbitrarily set, and after the two adjacent transients are overlapped, the two adjacent transients can be partially overlapped, seamlessly connected, or spaced.

In the present embodiment, the first movement mechanism 30 includes a driving module and a detection feedback module, the driving module is used for adjusting 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 an existing mechanism capable of outputting linear movement may be adopted, for example, any one of a lead screw nut mechanism, a rack and pinion mechanism, a linear cam mechanism, a hydraulic cylinder, an air cylinder and an electric cylinder is adopted. The drive module may be based on any of electric drive, hydraulic drive and pneumatic. When the output end of the driving module is connected to the light source mechanism 10 or the projection disk 20, any one of fixed connection, detachable connection, and movable connection may be used as long as at least one of the light source mechanism 10 and the projection disk 20 can be driven to move toward the other side stably in the direction of the preset eye axis 40. The driving module can output a reciprocating motion along the preset eye axis 40 direction, that is, can drive the light source mechanism 10 and the projection disk 20 to approach each other and drive them to move 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 ruler to obtain the relative displacement.

The projection disk 20 only needs to be a transparent plate, so that the precision requirement is not high, the processing cost is low, and the plate is easy to obtain; the projection disk 20 may be a circular plate, a square plate, or other polygonal plate. The reflection portion 203 is a part of the projection disk 20, and in the present embodiment, the reflection portion 203 is a solid structure and is integrally formed with other parts of the projection disk 20.

As shown in fig. 1 and fig. 2, in the present embodiment, a first surface 204 of the projection disk 20 facing the light source mechanism 10 and a second surface 205 facing away from the projection disk 20 are both flat surfaces. In other embodiments, as shown in fig. 3, the first surface 204 may be a spherical surface with a radius between 100mm and 300mm, or an ellipsoid, a paraboloid, a hyperboloid, an aspheric surface, or a free-form surface.

In this embodiment, both the first surface 204 and the second surface 205 of the projection disk 20 are frosted; in other embodiments, it is within the scope of the present disclosure that one of first surface 204 and second surface 205 may alternatively be sanded.

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

Example 2

The present embodiment provides a projection apparatus based on corneal 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, and accordingly, as shown in fig. 4, the shaping module 104 employs a cone lens, the thickness of the hollow cone beam 102 output by the cone lens changes along with the change of the diameter of the parallel light, and the two are in positive correlation, so that the width of the annular light projected on the projection disk 20 is adjustable, and therefore the annular light with a smaller annular width can be obtained by reducing the diameter of the parallel light emitted by the light source module 103 in the working condition with a high precision requirement, and further the detection precision is improved. Meanwhile, the projection device based on the corneal reflection can be suitable for a scene with large detection precision span.

Please refer to fig. 5 for understanding. 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, for example, emitting laser light, and the lens assembly is used for adjusting the width of the monochromatic collimated light and emitting the parallel light after adjusting the 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 collimated light of a single color, 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 is adjustable in the predetermined direction of the eye axis 40, so as to adjust the diameter of the parallel light output by the third lens module 1033, fig. 5 is configured to illustrate three transient states a, b, and c of the light source module 103, wherein two dotted lines are used to illustrate one motion trajectory of the first lens module 1031 and the second lens module 1032, and the diameters of the output light beams of the third lens module 10313 in the three transient states a, b, and c are changed when the positions of the two lens modules are changed (103c 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 an integer not less than 2, such as 2, 4 or 5.

In this 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, the second lens module 1032 and the third lens module 1033 are components including a plurality of lenses.

In this embodiment, the light source module 103 further includes a second moving mechanism and a third moving mechanism, the second moving mechanism is connected to the first lens module 1031 for driving the first lens module 1031 to move along the preset eye axis 40, and the third moving mechanism is connected to the second lens module 1032 for driving the second lens module 1032 to move along 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, employ any of a lead 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 the second and third moving mechanisms in this embodiment may be electrically, hydraulically, or pneumatically driven, and may also be implemented by manual driving, for example, manually rotating a lead screw in a lead screw and nut mechanism 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 using the second movement mechanism and the third movement mechanism, and increases the diameter variation range of the third lens output beam. In other embodiments, only the second movement mechanism or the third movement mechanism may be provided, that is, one of the lens assemblies is adjustable, the other two lens assemblies are fixed, or the fourth movement mechanism is provided to control the third lens module 1033 to move along the preset eye axis 40 at the same time as the second movement mechanism and the third movement mechanism, so as to further increase the diameter variation range of the output light beam of the third lens.

In this embodiment, the light source module 103 emits a light beam with an adjustable diameter by using the above structure, and in other embodiments, the light source module 103 may directly select an existing continuous zoom beam expander as a replacement means.

The other parts of the projection apparatus based on corneal reflection in this embodiment are the same as those in embodiment 1, and the description thereof is omitted.

Example 3

With continued reference to fig. 1, the present embodiment provides a corneal photography instrument, which employs the projection device based on corneal reflection as provided in any of the above embodiments, and further includes an observation module, where the observation module has an incident end and an observation end, the reflected light 60 passes through the reflection portion 203 and then enters the incident end, the incident end further reflects the reflected light 60 along a predetermined direction to the observation end, and the observation end is used for observing the reflected light 60. In this embodiment, the predetermined direction is perpendicular to the predetermined eye axis 40, and in other embodiments, the predetermined direction and the predetermined eye axis may be inclined, so that the reflected light 60 passing through the reflection portion 203 does not interfere with the light source mechanism 10. In the embodiment of the projection apparatus based on corneal reflection shown in FIG. 1, the dashed box represents the observation module.

In this embodiment, the observation module changes the trend of the reflected light 60 and plays a role in amplification, specifically, the observation module includes a spectroscope component and a magnifier module, the incident spectroscope component is used to change the propagation direction of the reflected light 60, and the reflected light 60 is reflected by the spectroscope component and amplified by the magnifier module in sequence, and is finally observed more clearly.

In the application process, the first motion mechanism can be enabled not to act, the corneal information can be observed in a static mode, the first motion mechanism can also be enabled to do stepless motion, and the morphological information of different positions of the cornea can be observed in a dynamic mode.

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

Example 4

Please refer to fig. 6 for understanding. The present embodiment provides a corneal topographer for detecting corneal topography. The corneal topographer comprises a projection device based on corneal reflection as provided in any of the embodiments above, and further comprises an imaging module 50, the imaging module 50 being configured to receive the reflected light 60 and generate image information. The corneal topography further comprises an image processing module, the imaging module 50 transmits image information to the image processing module, and the recording, analysis and calculation processing of the image information are realized through the image processing module; when the system is implemented specifically, 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 predetermined 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 onto the projection disk 20, and the imaging module 50 is disposed along the direction perpendicular to the preset eye axis 40, so that the space occupied by the imaging module 50 around the preset eye axis 40 is reduced, and the risk that the part outside the first end 501 of the imaging module 50 blocks the hollow cone beam 102 is reduced. In other embodiments, the first end portion 501 to the second end portion 502 may be alternatively arranged along a direction oblique to the preset eye axis 40.

In this embodiment, the imaging module 50 includes a beam splitter element 503, an imaging lens group 504 and an image sensor 505, the reflected light 60 is reflected into the imaging lens group 504 through the beam splitter element 503, the imaging lens group 504 focuses light on the image sensor 505, the image sensor 505 is configured to convert an optical 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 beam splitter component 503, and the second end 502 includes an image sensor 505.

In the present embodiment, the beam splitter component 503 is a filter (more specifically, a transflective filter) and is disposed at an angle of 45 ° with respect to the predetermined eye axis 40, so as to transmit the reflected light 60 of the cornea to the imaging lens group 504 along a direction perpendicular to the predetermined eye axis 40. The member for mounting the beam splitting mirror element 503 may be made of a light-transmitting material to prevent the hollow cone beam 102 from being blocked. Since the imaging lens group 504 focuses the reflected light 60 on 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, in this embodiment, the imaging module 50 does not output displacement in the preset eye axis 40 direction, so the imaging lens group 504 and the image sensor 505 are relatively static, and indeed, in other embodiments, if the imaging module 50 moves relative to the cornea in the preset eye axis 40 direction, 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 adopt any one of a single lens, a double cemented lens, an aspheric lens, and a lens group formed by any combination thereof, the image sensor may adopt a CCD or a 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 herein again.

As shown in fig. 6, in the present embodiment, the first moving mechanism 30 is connected to the projection disk 20 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 disposed. Specifically, the output end of the first moving mechanism 30 is connected to the projection disk 20, and the two can be fixed by clamping, fastening or welding, so as to maintain the stability of the projection disk 20 during the moving process. In use, the light source mechanism 10 and the imaging module 50 are static, the first moving mechanism 30 is dynamic, and the projection disk 20 is driven to move from far to near or from near to far relative to the light source mechanism 10 by controlling the first moving mechanism 30 to move, and the imaging module 50 is controlled to image a plurality of transient states during the period.

The corneal topographer further includes a mounting cup (not shown) that encloses a mounting cavity in which the corneal reflection-based projection device and imaging module 50 are disposed. The mounting cover has an integration function, and integrates the light source mechanism 10, the projection disc 20, the first motion mechanism 30 and the imaging module 50 together; the mounting cover also provides dust protection and prevents mechanical damage to the projection device and imaging module 50 from the environment. The mounting cover is provided with a detection hole which corresponds to the projection disk 20, so that light can smoothly spread between the cornea outside the mounting cover and the projection disk 20 inside the mounting cover. In use, the eye is directed at the inspection hole, the ring of light is transmitted through the inspection hole and into the cornea of the eye, and the reflected light 60 generated by the cornea is transmitted through the inspection hole and into the projection plate 20.

The function and principle of the corneal topographer will be described in conjunction with its structure. The cornea topographic map instrument projects the cornea, image information is obtained according to light information reflected by the cornea, the image information can be used independently to reflect local form information of the cornea and can also be used in a superposition mode, and the form of the cornea can be reflected more comprehensively after the image information is superposed, and even the real form of the cornea can be reflected completely. Defining the information obtained after the information of each image is superposed as a first result, wherein the embodiment form of the first result is consistent with the embodiment form of the information obtained by projecting the cornea through the existing Placido module and imaging the reflected light by a photographic 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 light under the condition that the width of the annular light is adjustable, so that the corneal topographer can be applied to scenes with different precision requirements and working conditions requiring precision adjustment; moreover, the width of the annular light can be adjusted by controlling the diameter of the light beam output by the light source module 103 and/or adjusting the cone angle of the hollow cone light beam 102, and the interval between adjacent annular lights can be adjusted by adjusting the output of the first movement mechanism 30 and/or the shooting frequency of the imaging module 50.

Taking the superposition of image information as an example to further describe the working principle of the corneal topography instrument, in the process of relative movement of the projection disk 20 and the light source mechanism 10, the imaging module 50 captures a plurality of moments for imaging, any one of three conditions of local superposition, seamless connection and interval existence may occur in superposition of annular light corresponding to two adjacent moments, and when a plurality of pieces of image information are superposed, if noise occurs due to the local superposition of the annular light, one group of data in a superposition area can be eliminated. For the scene with intervals, if the radial intervals between the annular lights are the same as those between the dark rings of the existing Placido disc, the detection effect of the corneal topographer disclosed by the invention is the same as that of the annular lights, but the corneal topographer disclosed by the invention has a simple structure and a simple manufacturing process.

The working principle of the corneal topography instrument is further described by taking the image information superposition as an example, different detection accuracies can be obtained by setting different parameters, for example, 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, the position relation between the annular light corresponding to the n +1 th shooting and the annular light corresponding to the n-th shooting of the imaging module 50 can be controlled, and thus different detection accuracies are obtained. In the practical application process, a chip is arranged 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, a key corresponds to each mode, and after a user selects the key with 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.

The working principle of the corneal topographer is further described by taking the superposition of the image information as an example, when the imaging module 50 performs imaging at equal intervals, the annular light distribution corresponding to each image information is uniform, that is, the superposed width of any two annular lights is consistent after superposition, or the interval width of any two annular lights is consistent after superposition, or the superposed widths of any two annular lights are not coincident and have no gap.

Example 5

The present embodiment provides a corneal topographer, which is different from embodiment 4 in that the first motion mechanism 30 drives an object as follows:

as shown in fig. 7, in the present embodiment, the first moving mechanism 30 is used to drive the reshaping module 104 to move relative to the projection tray 20, wherein the output end of the first moving mechanism 30 is connected to the reshaping module 104 to drive it to move along the predetermined eye axis 40, and the two can be fixed by clamping, fastening or welding, etc. to maintain the stability of the reshaping module 104 during the movement process. The imaging module 50 is arranged to be relatively stationary with respect to the projection disc 20, while in use the imaging module 50, the projection disc 20 and the cornea are relatively stationary, and accordingly the relative positions of the imaging lens group 504 and the image sensor 505 are unchanged. The projection disk 20 of the imaging module 50 is fixed on the mounting cover by clamping, fastening, welding and the like to realize the above function.

In this embodiment, the light source module 103 is configured to be stationary relative to the projection disk 20, and the light source module 103 is fixed on the mounting cover by clamping, fastening, welding, or the like, and alternatively, it is within the scope of the present invention that the light source module 103 is configured to be stationary relative to the shaping module 104.

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

In the using process, the projection disk 20 and the imaging module 50 are in a static state, and the shaping module 104 is driven by the first motion mechanism 30 to move from far to near or from near to far relative to the projection disk 20, and the imaging module 50 performs imaging in the process.

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

The other parts of the corneal topographer of this embodiment are the same as those of embodiment 4, and are not described again here.

Example 6

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

as shown in fig. 8, the output end of the first moving mechanism 30 is connected to the reshaping module 104 and the imaging module 50, and is used for driving the reshaping module 104 and the imaging module 50 to move together relative to the projection disk 20 in the direction of the preset eye axis 40. Meanwhile, the imaging lens group 504 in the imaging module 50 is configured to move between the beam splitter component 503 and the image sensor 505, so as to focus the light on the image sensor 505. In the embodiment, the light source module 103 is set to be stationary relative to the shaping module 104, and alternatively, the light source module 103 may be set to be stationary relative to the projection disk 20.

In this embodiment, the imaging module 50 further includes a fifth moving mechanism, an output end of the fifth moving mechanism is connected to the imaging lens assembly 504, and is used for driving the imaging lens assembly 504 to reciprocate between the beam splitter component 503 and the image sensor 505, so as to focus light on the image sensor 505; the solid double-headed lines shown above and below in fig. 8 are used 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 a linear movement, for example, any one of a lead 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 linkage, and the fifth movement mechanism automatically operates according to the output amount of the first movement mechanism 30.

In the using process, the projection disc 20 is in a static state, the shaping module 104 and the imaging module 50 are driven by the first motion mechanism 30 to move together towards a direction close to or away from the projection disc 20, and the imaging lens group 504 is driven by the fifth motion mechanism to move, so that light is always focused on the image sensor 505, and meanwhile, the imaging module 50 is controlled to perform imaging.

The other parts of the corneal topographer of this embodiment are the same as those of embodiment 4, and the description thereof is omitted.

Example 7

This is understood with reference to fig. 9. The present embodiment provides a corneal topography detection method, which uses any one of the above corneal topographers to detect 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 move relatively in the direction of the preset eye axis 40 by a first distance, 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, before the detection, the axis of the cornea on the second side 202 is made to coincide with the preset axis, that is, the cornea is located, the specific locating manner may be to adapt to the position of the projection disk 20 through the movement of 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 to finely adjust 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 moving mechanism 30 to drive the light output end 101 and the projection disk 20 to move relatively in the direction of the preset eye axis 40 for a first distance, the imaging module 50 is controlled to take a picture and obtain a plurality of image information:

the first movement mechanism 30 is configured to output an electrodeless movement (a back-and-forth linear movement along a preset eye axis), control the first movement mechanism 30 to drive the projection disk 20 to move at a constant speed for a first distance relative to the light output end 101, and during the first distance, the imaging module 50 shoots according to a preset frequency, so that the annular lights corresponding to the image information are uniformly distributed after being superimposed; adjust the initial distance of light output 101 and projection dish 20 and/or adjust the relative motion speed of light output 101 and projection dish 20 and/or adjust the shooting frequency of formation of image module 50 to make the outer diameter of the ring light that the formation of image module 50 (n + 1) th shooting corresponds equal to the inner diameter of the ring light that the nth shooting corresponds, thereby first result is continuous and nonoverlapping. Indeed, in other methods, the outer diameter of the ring light corresponding to the (n + 1) th shot of the imaging module 50 may be larger than the inner diameter of the ring light corresponding to the nth shot.

Example 8

The present embodiment provides a corneal topography detection method, which uses any one of the above corneal topographers to detect 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 move relatively 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;

In this embodiment, the cornea on the second side 202 is aligned with the predetermined axis before the detection, i.e. the cornea is positioned, in the same manner as in embodiment 7.

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

the first motion mechanism 30 is configured to output an infinite motion, the first motion mechanism 30 drives the projection disk 20 and the light output end 101 to move relatively for a plurality of times to reach a relative motion amount of a first distance, and the imaging module 50 is controlled to capture and form graphic information in a gap between two relative motions. The amount of motion of projection dish 20 and light output end 101 every time relative motion is the same, adjusts the initial distance of light output end 101 and projection dish 20 and/or adjusts the relative motion speed of light output end 101 and projection dish 20 and/or adjusts the shooting frequency of imaging module 50 to the external diameter that makes imaging module 50 the (n + 1) th time shoot the corresponding annular light equals the internal diameter that the nth time shot the corresponding annular light, thereby first result is continuous and nonoverlapping. Indeed, in other methods, the outer diameter of the ring light corresponding to the (n + 1) th shot of the imaging module 50 may be larger than the inner diameter of the ring light corresponding to the nth 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 attributes 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 corneal reflection is characterized by comprising a light source mechanism, a plate-shaped projection disc and a first movement mechanism, wherein the light source mechanism is provided with a light ray 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 ray output end and projecting annular light on a first side of the projection disc, and the first movement mechanism is used for contracting and expanding the annular light by adjusting the relative position between the light ray output end and the projection disc in the direction of the preset eye axis; a cornea on a second side of the projection disc receives the annular light to form reflected light, and the reflected light can be changed in optical path after passing through the reflection part of the projection disc; the reflection part is positioned in 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 corneal reflection-based projection device of claim 2, wherein the diameter of the collimated light emitted from the light source module is adjustable, and the thickness of the hollow cone beam output by the shaping module is changed along with the change of the diameter of the collimated light.

4. The corneal reflection-based projection device of claim 2, wherein the light source module comprises a light source, a first lens module for receiving parallel light from 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 wherein the 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 corneal reflection-based projection device of claim 4, wherein the light source module further comprises a second movement mechanism for driving the first lens module to move along the predetermined eye axis direction and/or a third movement mechanism for driving the second lens module to move along the predetermined eye axis direction.

6. The corneal reflection-based projection device of claim 2, wherein the light source module is a continuous variable power beam expander.

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

the shaping module comprises a conical lens, 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 motion mechanism drives the projection plate to move relative to the light source mechanism, or the first motion mechanism drives the light source module and the reshaping module to move together relative to the projection plate, or the first motion mechanism drives the reshaping module to move relative to the light source module and the projection plate.

9. The corneal reflection-based projection device of claim 1, wherein the first movement mechanism comprises a drive module for adjusting the relative position of the light source mechanism and the projection disk in the preset ocular axis direction, 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 disc, which faces the light source mechanism, is a plane, a spherical surface, 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 disc facing the light source mechanism and a second surface of the projection disc facing away from the light source mechanism is a frosted surface;

the projection disk is made of glass or plastic.

12. A corneal photocopier comprising a projection device based on corneal reflection as claimed in any one of claims 1 to 11 and an observation module, wherein the observation module comprises an incident end and an observation end, and the reflected light passes through the reflection portion and then enters the incident end, and further propagates to the observation end along a predetermined direction under the action of the incident end, and the predetermined direction is inclined or perpendicular to the direction of the predetermined axis of the eye.

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 preset ocular 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 the light onto 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 the parallel 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 set to be relatively static, and the beam splitter 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 the parallel emitted by the light source module into the annular beam of the cone;

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 beam splitter 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 beam splitter element and the image sensor so as to focus light on the image sensor.

18. The corneal topographer of claim 13,

the cornea topographer also comprises an image processing module used for calculating and/or analyzing the image information;

the cornea topographic map instrument further comprises an installation cover, the installation cover encloses an installation cavity, and the projection device based on corneal reflection and the imaging module are arranged in the installation cavity.

19. A corneal topography detection method implemented using a corneal topographer according to any one of claims 13 to 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 ray output end of the light source component and the projection disc to relatively move for a first distance in the preset eye axis direction, and controlling the imaging module to shoot and obtain a plurality of image information in the period;

and superposing the image information.

20. The corneal topography detecting method as claimed in claim 19, wherein said controlling said first moving mechanism to drive said light output end and said projection disk to move relatively in said predetermined axial direction for a first distance controls said imaging module to capture and obtain a plurality of image information:

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

22. The corneal topography detecting method according to claim 20 or 21, wherein the step of driving the light output end and the projection disk to relatively move in the preset eye axis direction by a first distance through the first moving mechanism, during which the imaging module is controlled to capture and obtain a plurality of image information further comprises: