WO2021110108A1

WO2021110108A1 - Vision testing apparatus

Info

Publication number: WO2021110108A1
Application number: PCT/CN2020/133676
Authority: WO
Inventors: 张科宇
Original assignee: 深圳市金泰坦科技有限公司
Priority date: 2019-12-06
Filing date: 2020-12-03
Publication date: 2021-06-10
Also published as: CN110811534A

Abstract

A vision testing apparatus, comprising: a light generating assembly (300), used for producing parallel light beams; a testing assembly (200), comprising a pattern sheet (210), a vision testing table being disposed on the pattern sheet (210); and an imaging assembly (400), comprising a plurality of convex mirrors used for magnification of the projected pattern and far-distance imaging; a first cavity (130), a first opening (110), and a second opening (120) are disposed in a first shell (100), the light generating assembly (300) and the imaging assembly (400) being arranged in the first cavity (130), and the pattern sheet (210) being arranged between the light generating assembly (300) and the imaging assembly (400); the parallel light produced by the light generating assembly (300) illuminates the pattern sheet (210), projecting the vision testing table onto the imaging assembly (400), and the imaging assembly (400) magnifies and implements far-distance imaging of the vision testing table. The present vision testing apparatus eliminates the complexity of original testing methods, and can detect whether the vision of an eye has a problem, such as near-sightedness, simply by placing the vision testing apparatus against the eye, thereby reducing costs, facilitating use by more people, and being capable of testing at any time and place.

Description

Vision detection device

Technical field

This application relates to medical and health care products, in particular to a vision detection device.

Background technique

At present, there are three methods commonly used in the detection of vision problems in the market:

The first is to use a visual acuity chart for testing. It is a visual acuity chart with a national standard pattern, hung at a certain distance, such as 5 meters away, and then the eye chart is turned on. People stand 5 meters away and watch the visual acuity chart monocularly. The shape of each pattern, according to the true degree of the shape seen, corresponds to different indicators on the eye chart to complete the vision test. This test method is an international general method, mainly used in hospitals. The disadvantage is that the eye chart is due to the size of the eye chart and the height of the human eye. Different heights of the human body must correspond to the eye chart of different heights, resulting in the hanging height of the eye chart. It is difficult to apply to all people, so the size of the eye chart has certain national standard size requirements. Due to the size requirements of the visual acuity chart, the detection range of the visual acuity chart distinguishes a certain range from small patterns to large patterns, resulting in inaccurate measurement accuracy such as ranges. At the same time, the detection brightness of the eye chart also has certain requirements, and the brightness index below the required brightness will also cause the test to be inaccurate. These requirements are not clear to the general user, so it is not accurate for the general user to purchase the eye chart test by himself. Since hospitals or optical shops know the above requirements, the eye chart is usually used as a test method in hospitals or optical shops.

The second is to use the vision testing equipment commonly used in hospitals or optical shops. This testing equipment is a photoelectric automatic control method that relaxes the eyes through fog vision, and then emits light. After the light passes through the eyes, there will be diopter, so as to obtain vision detection astigmatism. Degree detection and so on. After checking the vision problem of the eye through the instrument, check with the hospital or eye shop to determine the vision problem. Due to the high price of the testing equipment, it is impossible to carry out the detection of every household anytime and anywhere. Failure to detect in time can easily cause early vision problems. As time goes on, the vision problems become more and more serious after they are discovered late.

The third type is the vision test for mobile phone screen display patterns recently launched in the United States. The mobile phone screen is used as an eye chart, and then the mobile phone is controlled to display different patterns for observation. A test tube and a mobile phone are required to complete the test. The optical test tube is pressed on the display screen of the mobile phone, and the mobile phone is used to display different patterns, perform a vision test, and then select and purchase services on the mobile phone. The disadvantage of this detection method is that it is very inconvenient to operate by one person. When the tested person puts his eyes close to the test tube and then close to the screen of the mobile phone to watch, it is inconvenient for the finger to operate on the mobile phone screen, and it is more convenient to require the assistance of others. In addition, the mobile phone and the test tube and the eyes must all be close together to test. In order to avoid multiple ways of shaking, the mobile phone screen should be placed flat on a fixed table, and then the test tube should be pressed on the mobile phone screen, and the human body should bend over. Lower your head for detection. There will be a certain difference between this posture and the vision of the human body in an upright standing or sitting posture. Even breathing fluctuations will also affect the accuracy of the detection. It is difficult to guarantee the selection after the test. There is accuracy in the process of purchasing follow-up services, such as matching glasses.

However, for remote areas and economically underdeveloped areas, due to lack of resources, it is difficult to popularize early detection when vision problems occur, which makes it difficult to prevent and protect vision problems that occur in the future.

Summary of the invention

The technical problem to be solved by this application is to provide a vision detection device in view of the shortcomings of the prior art.

The technical problem to be solved by this application is solved by the following technical solutions: a vision detection device, including a light generating component, a detection component, an imaging component, and a first housing;

The light generating component is used to generate parallel light beams;

The detection component includes a pattern sheet on which a vision test table is arranged;

The imaging component includes a plurality of convex mirrors for magnifying the projected pattern and imaging at a long distance;

The first housing is provided with a first cavity, a first opening and a second opening, the first opening and the second opening are respectively provided at both ends of the first housing, the first opening , The first cavity and the second opening pass through, the light generating component is disposed in the first cavity and adjacent to the first opening, and the imaging component is disposed in the first cavity and adjacent to In the second opening, the pattern sheet is arranged between the light generating assembly and the imaging assembly, the first opening is provided with a cover, and the second opening is provided with a transparent sheet;

The parallel light generated by the light-generating component irradiates the pattern sheet, and projects the vision test table on the imaging component, and the imaging component magnifies the vision test table and forms images at a distance.

Further, the light generating assembly includes an incident light generating mechanism and a parallel light lens;

The incident light generating mechanism is used to generate incident light and irradiate the incident light onto the parallel light lens;

The parallel light lens is used to convert the incident light into parallel light and emit it onto the pattern sheet.

Further, the incident light generating mechanism includes a light source and a control circuit;

The light source; used to generate incident light;

The control circuit is used to control the light source.

Further, the incident light generating mechanism includes a light control sheet;

The cover includes a light incident sheet for injecting light;

The light control sheet is provided with a light-transmitting area, and the incident light is emitted through the light-transmitting area.

Further, the imaging component includes a first lens and a second lens;

The first lens is used to receive a first image of the vision test chart, and a second image is generated through the first lens, and the second image is between the first lens and the second lens;

The second lens is used for magnifying the input second image and imaging at a distance.

Further, the pattern sheet is provided with a plurality of detection areas, and the detection areas include a myopia detection area, a hyperopia detection area, an astigmatism detection area, a presbyopia detection area and/or a myopia detection area, and the detection area is provided with a corresponding detection area. Eyesight test form.

Further, the detection component further includes a selection mechanism;

The selection mechanism includes a second housing, a fixing part and a switch part; the second housing is provided with a second cavity, a third opening and a fourth opening, and the fixing part is arranged in the second cavity , Used to fix the pattern sheet, the first housing is further provided with a fifth opening, the fifth opening, the third opening and the second cavity pass through, and the pattern sheet passes through the The fifth opening and the third opening are partially arranged in the second cavity, one end of the switch element is embedded in the fourth opening, and the other end of the switch element is arranged in the second cavity, Pressing the switch member can push the pattern sheet to rotate to select the test area.

Further, the fixing member includes a fixing shaft, a first fixing sheet and a second fixing sheet, the image sheet, the first fixing sheet and the second fixing sheet are respectively provided with through holes, and the image sheet is clamped in Between the first fixing piece and the second fixing piece, the fixing shaft passes through the through hole and is fixed on the second housing.

Further, the switch member includes a first button, a push rod and a return spring, the first button and the return spring are respectively arranged at both ends of the push rod, and the first button is embedded in the fourth In the opening, the return spring is fixed in the second housing.

Further, the selection mechanism further includes a limiting member, the limiting member includes a bracket and a one-way elastic locking piece, the bracket is linked with the switch member, and the first fixing piece is provided with a plurality of bosses, A plurality of notches are provided on the circumference of the second fixing piece, and the notches correspond to the detection area, and the push rod is provided with a groove. When the first button is pressed, the groove catches the The boss makes the push rod push the first fixing piece.

Due to the adoption of the above technical solutions, the beneficial effects of this application are:

The vision detection device provided by the embodiments of the present application includes: a light generating component for generating parallel light beams; a detection component including a pattern sheet on which a vision test table is arranged; and an imaging component including a plurality of convex mirrors for projecting The coming pattern is enlarged and imaged at a long distance; the first housing is provided with a first cavity, a first opening and a second opening, the light generating component and the imaging component are arranged in the first cavity, and the pattern sheet is arranged on the light generating component And the imaging component; the parallel light generated by the light-generating component illuminates the pattern sheet to project the vision test table on the imaging component, and the imaging component magnifies the vision test table and images in the distance. Using the vision detection device of the present application eliminates the cumbersomeness of the original test method. Only by leaning the vision detection device on the human eye, it can detect whether there is a vision problem (such as myopia, etc.) in the human eye, thereby reducing the cost. It is conducive to the use of more people and can be tested anytime, anywhere.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of the vision detection device in the first embodiment of the application in an implementation manner;

2 is a schematic structural diagram of the vision detection device in embodiment 1 of this application in another implementation manner;

FIG. 3 is a schematic structural diagram of the vision detection device in the second embodiment of the application in an implementation manner; FIG.

4 is a schematic structural diagram of the vision detection device in the second embodiment of the application in another implementation mode;

FIG. 5 is a schematic structural diagram of a detection component without a housing in the second embodiment of the application from a first perspective;

FIG. 6 is a schematic diagram of the structure of the detection component without a housing in the second embodiment of the present application from a second perspective; FIG.

FIG. 7 is a schematic structural diagram of a detection component without a housing in the second embodiment of the application in a third perspective; FIG.

FIG. 8 is a schematic diagram of long-distance imaging observed by human eyes by the vision detection device in the second embodiment of the application.

Detailed ways

Hereinafter, the present invention will be further described in detail through specific embodiments in conjunction with the drawings. This application can be implemented in a variety of different forms and is not limited to the implementation described in this embodiment. The following specific embodiments are provided for the purpose of facilitating a clearer and thorough understanding of the disclosure of the present application. The words indicating directions such as up, down, left, and right are only for the position of the structure shown in the corresponding drawings.

However, those skilled in the art may realize that the detailed description of one or more of them may be omitted, or other methods, components, or materials may also be used. In some examples, some implementations are not described or are not described in detail.

The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequence or technical meaning.

In addition, the technical features and technical solutions described herein can also be combined in any suitable manner in one or more embodiments. For those skilled in the art, it is easy to understand that the steps or operation sequence of the method related to the embodiments provided herein can also be changed. Therefore, any order in the drawings and embodiments is only for illustrative purposes, and does not imply that a certain order is required, unless it is clearly stated that a certain order is required.

Example one:

Please refer to FIG. 1 and FIG. 2, an embodiment of the vision detection device of the present application includes a light generating assembly 300, a detection assembly 200, an imaging assembly 400 and a first housing 100. The first housing 100 is made of waterproof material.

The light generating assembly 300 is used to generate parallel light beams;

The detection component 200 includes a pattern sheet 210 on which is provided with a vision test table; the pattern sheet 210 is made of a transparent material;

The imaging component 400 includes a plurality of convex mirrors for magnifying the projected pattern and imaging at a long distance;

The first housing 100 is provided with a first cavity 130, a first opening 110, and a second opening 120. The first opening 110 and the second opening 120 are respectively provided at both ends of the first housing 100. A cavity 130 and the second opening 120 pass through, the light generating component is disposed in the first cavity 130, and the light generating component is adjacent to the first opening end 110, the imaging component is disposed in the first cavity 130, and the imaging component is adjacent to the first cavity 130. Two openings 120, the pattern sheet 210 is arranged between the light-generating assembly and the imaging assembly, the first opening 110 is provided with a cover 111, and the second opening 120 is provided with a transparent sheet 121; wherein the transparent sheet 121 is based on the imaging of the pattern sheet 210. Conversely, it can be a flat transparent sheet or a convex lens sheet.

The parallel light generated by the light generating component 300 illuminates the pattern sheet 210, and projects the vision test table on the imaging component, and the imaging component magnifies the vision test table and images in the distance.

Further, the light generating assembly 300 may include an incident light generating mechanism and a parallel light lens 310;

The incident light generating mechanism is used to generate incident light and irradiate the incident light onto the parallel light lens 310; the parallel light lens 310 is used to convert the incident light into parallel light and emit it onto the pattern sheet 210.

In an embodiment, the incident light generating mechanism may include a light source 321 and a control circuit (not shown). The light source 321 is used to generate incident light; the control circuit is electrically connected to the light source 321 and is used to control the light source 321. The light source 321 may be an LED lamp or small lamp beads emitting white light. Further, the incident light generating mechanism may also include a photosensitive element 322, which is electrically connected to the light control circuit, and is used to control the brightness of the light source 321 under the control of the light control circuit, so that the brightness of the light source 321 is always kept consistent.

In another embodiment, the incident light generating mechanism may include a light control sheet 331, and the light control sheet 331 is a light-shielding sheet that only transmits light at the center. The cover 111 may be a light incident film, which can be used to inject light, and the light incident film may be a frosted film, an atomized film, a translucent film, etc., as long as it belongs to the astigmatism film type. The role of the light incident film as a diffuser is to prevent direct light from causing glare, which affects the test. The light control sheet 331 is provided with a light-transmitting area 332, and the incident light is emitted through the light-transmitting area 332. The light-transmitting area 332 may be a transparent area or a through hole.

Further, the imaging component 400 may include a plurality of lenses, and the number of lenses can be set as required. In this embodiment, the imaging component 400 may include a first lens 410 and a second lens 420. The first lens 410 is used to receive the first image of the vision test table, and the second image is generated through the first lens 410, and the second image is between the first lens 410 and the second lens 420; the second lens 420 is used to combine The input second image is enlarged and imaged in the distance.

This application turns the light into parallel light, and the parallel light passes through the transparent pattern sheet. At this time, the transparent pattern sheet is used as an object to be imaged through the first lens, and then the image formed by the first lens will be used as the second lens. The object is imaged again. Those skilled in the art can know that the image at this time is an extension of the straight line vision of the human eye from an optical point of view, and what the human eye sees is like a magnified image at a long distance. For example, the national standard vision test distance is The distance of 5 meters is set to 5 meters. At this time, the small detection pattern at a short distance will be seen by the human eye as a magnified pattern at a long distance, realizing the 5-meter test of the visual acuity chart in the international medical industry.

Using the vision detection device of the present application eliminates the cumbersomeness of the original test method. Only by leaning the vision detection device on the human eye, it can detect whether there is a vision problem (such as myopia, etc.) in the human eye, thereby reducing the cost. It is conducive to the use of more people and can be tested anytime, anywhere. There is no requirement for the tester's human body posture, and the vision detection device of the present application can be used for testing in a comfortable posture, and vision can be detected anytime and anywhere, and vision problems can be found early, so that the vision can be protected in an appropriate way.

Embodiment two:

As shown in FIGS. 3 to 8, the difference between the vision detection device provided in this embodiment and the first embodiment is that the detection assembly 200 further includes a selection mechanism.

The pattern sheet 210 may also be provided with multiple detection areas. The detection areas may include a myopia detection area, a hyperopia detection area, an astigmatism detection area, a presbyopia detection area and/or a myopia detection area, and the detection area is provided with a corresponding vision test table. The selection mechanism is used to select the detection area in the pattern sheet 210, so that the selected detection area is located in the light path, so as to realize the corresponding detection of vision.

Further, the selection mechanism may include a second housing 220, a fixing part and a switch part; the second housing 220 is provided with a second cavity 221, a third opening 222 and a fourth opening (not shown), and the fixing part is arranged at The second cavity 221 is used to fix the gobo 210. The first housing 110 is also provided with a fifth opening 112. The fifth opening 112, the third opening 222 and the second cavity 221 pass through, and the gobo 210 passes through the second cavity. The five openings 112 and the third opening 222 are partially disposed in the second cavity 221. One end of the switch element is embedded in the fourth opening, and the other end of the switch element is set in the second cavity 221. Pressing the switch element can push the pattern sheet 210 to rotate, and the test area can be selected so that the selected detection area is located in the light path.

Further, the fixing member may include a fixing shaft 233, a first fixing piece 231, and a second fixing piece 232. The image piece 210, the first fixing piece 231 and the second fixing piece 232 are respectively provided with through holes, and the image piece 210 is clamped. Between the first fixing piece 231 and the second fixing piece 232, the fixing shaft 233 penetrates through the through hole and is fixed on the second housing 220.

Further, the switch member may include a first button 241, a push rod 242, and a return spring 243. The first button 241 and the return spring 243 are respectively arranged at both ends of the push rod 242. The first button 241 is embedded in the fourth opening to reset The spring 243 is fixed in the second housing 220.

Further, the selection mechanism may also include a limiting member, the limiting member may include a bracket (not shown) and a one-way elastic locking piece 251, the bracket and the switch piece are linked, the first fixing piece 231 is provided with a boss 234, the convex There may be multiple platforms 234. There are notches 235 on the circumference of the second fixing piece 232, and there are multiple notches 235, which may correspond to the detection area. The push rod 242 is provided with grooves 244, grooves 244 and bosses 234. When the first button 241 is pressed, the groove 244 clamps the boss 234, so that the push rod 242 pushes the first fixing piece 231 to drive the pattern piece 210 to rotate. When the first button 241 is released, the first button 241 is reset. Under the action of the spring, it bounces up 243, the one-way elastic locking piece 251 clamps the notch 235 of the second fixing piece 232, and the pattern piece 210 stops rotating.

Pressing the first button 241 can drive the push rod 242 to push the pattern sheet 210 printed with different patterns. A circle around the second fixing sheet 232 is provided with recessed notches 235. The number of notches 235 corresponds to the number of detection areas. The one-way elastic lock piece 251 is pressed in the notch 235 to prevent the pattern piece 210 from moving. Each time the first button 24 is pressed, the push rod 242 pushes the pattern piece 210, the one-way elastic lock piece 251 is opened, and the pattern piece 210 moves to the position of the next detection area, and then releases the hand. The first button 241 is bounced by the return spring 243, and the notch of the second fixing piece 232 is blocked by the one-way elastic lock piece, completing the pattern replacement process.

Further, the vision detection device provided in this embodiment can also be connected to a mobile terminal, such as a mobile phone, etc., via a network, and specifically, an APP can be installed on the mobile terminal. The selection mechanism may also include a control module 261 and a second button 262. The control module 261 is used to connect to an external network. Press the second button 262 to transmit the detection data to the APP of the mobile terminal through the control module 261 to facilitate network connection. Consulting and follow-up services.

This application turns the light into parallel light, and the parallel light passes through the transparent pattern sheet. At this time, the transparent pattern sheet is used as an object to be imaged through the first lens, and then the image formed by the first lens will be used as the second lens. The object is imaged again. Those skilled in the art can know that the image at this time is an extension of the straight line vision of the human eye from an optical point of view, and what the human eye sees is like a magnified image at a long distance. For example, the national standard vision test distance is The distance of 5 meters is set to 5 meters. At this time, the small detection pattern at a short distance will be seen by the human eye as a magnified pattern at a long distance, realizing the 5-meter test of the visual acuity chart in the international medical industry. The gobo can be rotated in one direction through a button. There are various patterns on the gobo for vision testing, such as near vision area, hyperopia area, astigmatism area, color blindness area, etc., can be added to the gobo. , There is corresponding vision data in the pattern. When a person's hand presses the button, different vision problems can be detected according to different patterns, so as to complete the test for related vision problems. As an early preventive test for common vision problems, it can fully satisfy Claim.

The working process of the vision detection device of the present application (the imaging component is provided with two lenses as an example):

For devices that use natural light, the natural light passes through the light incident sheet, and then passes through the light control sheet with only the center of the light to be incident on the parallel light lens to generate parallel light. For devices that use light sources, the battery drives the light source and the photosensitive element at the same time. , The brightness of the light-emitting light source is controlled by the photosensitive element to keep the same. When the light from the light-emitting source hits the parallel light lens, parallel light is generated. When the parallel light passes through the pattern sheet in parallel, it will project the pattern of the vision test chart on the first lens, the first lens will produce an image between the first lens and the second lens, and then the second lens will take the image as input to perform Enlarge the image and image it at a long distance. In Figure 8, 500 is the human eye, A is the remote imaging location, and L is the distance between the human eye and the remote imaging location. The detection area may include a myopia detection area, a hyperopia detection area, an astigmatism detection area, a presbyopia detection area and/or a myopia detection area, and the detection area is provided with a corresponding vision test table. There are corresponding vision data in the vision test table. By comparing the vision data, you can know what vision problems are, and you can quickly understand the user's vision problems, so that you can go to the hospital or optical shop to deal with it in advance.

The above content is a further detailed description of the application in conjunction with specific implementations, and it cannot be considered that the specific implementation of the application is limited to these descriptions. For those of ordinary skill in the technical field to which this application belongs, several simple deductions or substitutions can be made without departing from the concept of this application.

Claims

A vision detection device, which is characterized by comprising a light generating component, a detection component, an imaging component and a first housing;

The light generating component is used to generate parallel light beams;

The detection component includes a pattern sheet on which a vision test table is arranged;

The imaging component includes a plurality of convex mirrors for magnifying the projected pattern and imaging at a long distance;

The first housing is provided with a first cavity, a first opening and a second opening, the first opening and the second opening are respectively provided at both ends of the first housing, the first opening , The first cavity and the second opening pass through, the light generating component is disposed in the first cavity and adjacent to the first opening, and the imaging component is disposed in the first cavity and adjacent to In the second opening, the pattern sheet is arranged between the light generating assembly and the imaging assembly, the first opening is provided with a cover, and the second opening is provided with a transparent sheet;

The parallel light generated by the light generating component irradiates the pattern sheet, and projects the vision test table on the imaging component, and the imaging component magnifies the vision test table and images it at a distance.
8. The device of claim 1, wherein the light generating component comprises an incident light generating mechanism and a parallel light lens;

The incident light generating mechanism is used to generate incident light and irradiate the incident light onto the parallel light lens;

The parallel light lens is used to convert the incident light into parallel light and emit it onto the pattern sheet.
3. The device of claim 2, wherein the incident light generating mechanism comprises a light source and a control circuit;

The light source; used to generate incident light;

The control circuit is used to control the light source.
3. The device of claim 2, wherein the incident light generating mechanism comprises a light control sheet;

The cover includes a light incident sheet for injecting light;

The light control sheet is provided with a light-transmitting area, and the incident light is emitted through the light-transmitting area.
The device of claim 1, wherein the imaging component includes a first lens and a second lens;

The first lens is used to receive a first image of the vision test chart, and a second image is generated through the first lens, and the second image is between the first lens and the second lens;

The second lens is used for magnifying the input second image and imaging at a distance.
The device according to any one of claims 1 to 5, wherein the pattern sheet is provided with a plurality of detection areas, and the detection areas include a myopia detection area, a hyperopia detection area, an astigmatism detection area, and a presbyopia detection area. Area and/or myopia detection area, the detection area is provided with a corresponding vision test table.
8. The device of claim 6, wherein the detection component further comprises a selection mechanism;

The selection mechanism includes a second housing, a fixing part and a switch part; the second housing is provided with a second cavity, a third opening and a fourth opening, and the fixing part is arranged in the second cavity , Used to fix the pattern sheet, the first housing is further provided with a fifth opening, the fifth opening, the third opening and the second cavity pass through, and the pattern sheet passes through the The fifth opening and the third opening are partially arranged in the second cavity, one end of the switch element is embedded in the fourth opening, and the other end of the switch element is arranged in the second cavity, Pressing the switch member can push the pattern sheet to rotate to select the test area.
The device according to claim 7, wherein the fixing member comprises a fixing shaft, a first fixing sheet and a second fixing sheet, and the image sheet, the first fixing sheet and the second fixing sheet are respectively provided with Through holes, the image sheet is clamped between the first fixing sheet and the second fixing sheet, and the fixing shaft is penetrated in the through hole and fixed on the second housing.
The device according to claim 8, wherein the switch member comprises a first button, a push rod and a return spring, and the first button and the return spring are respectively arranged at both ends of the push rod, so The first button is embedded in the fourth opening, and the return spring is fixed in the second housing.
9. The device according to claim 9, wherein the selection mechanism further comprises a limiting member, the limiting member includes a bracket and a one-way elastic lock plate, the bracket is linked with the switch member, and the second A fixed piece is provided with a plurality of bosses, a plurality of notches are provided on the circumference of the second fixed piece, the notches are corresponding to the detection area, the push rod is provided with a groove, and the first button is pressed When the groove clamps the boss, the push rod pushes the first fixing piece.