CN112614389A

CN112614389A - Calculus model stereoscopic projection system for college mathematics teaching

Info

Publication number: CN112614389A
Application number: CN202011529742.5A
Authority: CN
Inventors: 陈文平; 蒋利华; 王营春; 唐艳
Original assignee: Guilin University of Electronic Technology
Current assignee: Guilin University of Electronic Technology
Priority date: 2020-12-22
Filing date: 2020-12-22
Publication date: 2021-04-06
Anticipated expiration: 2040-12-22
Also published as: CN112614389B

Abstract

The invention belongs to the technical field of teaching aids, in particular to a calculus model stereoscopic projection system for college mathematics teaching, which comprises a service platform, a terminal APP and a projection device, wherein the service platform is connected with the terminal APP; the terminal APP is installed in a common smart phone; the terminal APP is connected with the service platform through a network and exchanges data; uploading, downloading and sharing a calculus teaching model video among the teachers through a service platform; the service platform comprises a model conversion module, a holographic video and a video processing module, wherein the model conversion module is used for converting a calculus model video uploaded by a teacher through a terminal APP into a holographic video which can be used by a projection device; the teacher uses a smart phone provided with a terminal APP to play a holographic video, places the smart phone into a projection device, and displays a stereoscopic image through the projection device; the invention has simple structure, convenient operation, convenient movement and good teaching demonstration effect, can be used in various environments and is suitable for popularization and use.

Description

Calculus model stereoscopic projection system for college mathematics teaching

Technical Field

The invention belongs to the technical field of teaching aids, and particularly relates to a calculus model stereoscopic projection system for college mathematics teaching.

Background

At present, in the process of mathematical education, there are no two different modes for the demonstration of the mathematical stereo model, one mode is that a teacher holds the mathematical stereo model on a platform for on-site demonstration, and the mode is limited by that the volume of the mathematical stereo model is too small, so that students at a far distance cannot clearly see the details of the mathematical stereo model; another way to show the mathematical stereo model is to show a photo of the mathematical stereo model by a projector, and since the photo is taken from a certain angle, the mathematical stereo model cannot be completely and truly reflected.

Also there is some technical scheme among the prior art, like the chinese patent with application number CN201720037584.9, through the cooperation of projection equipment and projection curtain, the integration of projection curtain and blackboard has been reached, the work degree of difficulty of teaching personnel has been alleviateed, but not reach the stereoeffect, only adopt traditional plane projection equipment, it is too abstract not to solve traditional projection, the student understands the difficulty, the problem of study progress has been influenced, and simultaneously, projection equipment structure in this scheme is complicated, the operation degree of difficulty is higher, and can not remove easily, arrangement cost is higher.

Disclosure of Invention

The invention provides a calculus model stereoscopic projection system for college mathematics teaching, which aims to make up the defects of the prior art, avoid the time waste of a teacher hand-drawing mathematical model in the teaching process, and solve the problems that the existing mathematical model display teaching aid cannot perform stereoscopic projection, is inconvenient to move and adjust and is complex in structure and operation.

The technical scheme adopted by the invention for solving the technical problems is as follows: the invention discloses a calculus model stereoscopic projection system for college mathematics teaching, which comprises a service platform, a terminal APP and a projection device, wherein the service platform is connected with the terminal APP; the terminal APP is installed in a common smart phone; the terminal APP is connected with the service platform through a network and exchanges data; uploading, downloading and sharing a calculus teaching model video among the teachers through a service platform; the service platform comprises a model conversion module, a holographic video and a video processing module, wherein the model conversion module is used for converting a calculus model video uploaded by a teacher through a terminal APP into a holographic video which can be used by a projection device; the teacher uses a smart phone provided with a terminal APP to play a holographic video, places the smart phone into a projection device, and displays a stereoscopic image through the projection device;

wherein, in the teaching process, a teacher can log in a service platform through a smart phone, a proper calculus teaching model is selected from the service platform to be played, then the smart phone is placed in a projection device, a stereoscopic image is displayed through the projection device for the students to watch, and the teaching effect is improved, meanwhile, the teacher can manufacture a holographic video through a model conversion module in the service platform for the projection device to display the stereoscopic image, so that the difficulty and the time for the teacher to manufacture the calculus teaching model are reduced, meanwhile, the teacher can share the manufactured excellent model on the service platform for other teachers to use, the utilization rate and the teaching value of the teaching model are improved, meanwhile, the holographic video is played through the smart phone and the stereoscopic image is displayed through the projection device, and the convenience for the teacher to use the calculus teaching model in the teaching is realized, the problem that a teacher cannot change and change the model at any time when using a teaching aid to display the calculus model in the teaching process, and the teaching effect of the teacher is influenced due to the fact that the model type is relatively single is avoided;

the projection device comprises a box body; an upper cover is hinged above the box body; a handle is fixedly arranged in the middle of the upper surface of the upper cover; a hinge seat is fixedly arranged on the side wall in the box body; a support rod is arranged in the box body; the tail end of the supporting rod is fixedly provided with a rotating shaft; the rotating shaft is rotatably arranged on the hinge seat; the top end of the telescopic rod is fixedly provided with a connecting bracket; a fixing plate is fixedly arranged at one end of the connecting bracket, which is far away from the telescopic rod; an imaging device is fixedly arranged at the center of the side surface of the fixing plate far away from the connecting bracket; the imaging device is the projection device described in Chinese patent with application number CN 201420304344.7; the center line of the projection device in the length direction is superposed with the center line of the support rod; a protective cover is fixedly arranged on the side surface of the fixing plate far away from the connecting bracket; the protective cover is made of a plastic material with good transparency and light weight; the protective cover is square, and the projection device is positioned in the protective cover; when the supporting rod is kept in a horizontal state in the box body, the protective cover does not contact the bottom surface of the box body and the lower surface of the upper cover; a first magnetic block is fixedly arranged on the side surface of the box body; when the supporting rod is kept in a vertical state in the box body, the supporting rod is adsorbed on the first magnetic block; when the supporting rod is kept in a vertical state, the protective cover is positioned above the box body, and the protective cover and the box body are not contacted with each other;

a gap is formed between the fixing plate and the top end of the supporting rod, and the fixing plate and the supporting rod are not in direct contact; the connecting bracket is fixedly provided with an extrusion column; the extrusion column is positioned on the connecting bracket in a region vertical to the support rod; the extrusion column comprises a first mounting cylinder; a first spring is fixedly arranged in the first mounting cylinder; a lifting column is arranged in the first mounting cylinder in a sliding manner; the first spring is positioned between the lifting column and the bottom surface in the first mounting cylinder; a placing plate is fixedly arranged at one end of the lifting column, which is far away from the first mounting cylinder; the placing plate is positioned in a gap between the fixing plate and the supporting rod; after the lifting column is lifted from the first mounting cylinder, the placing plate is just in contact with the side face, close to the supporting rod, of the fixing plate; the smart phone is placed on the side face, close to the fixing plate, of the placing plate; the intersection point of the middle lines in the length direction and the width direction of the placing plate is positioned on the central line of the supporting rod; the placing plate and the end face of the supporting rod close to the fixing plate are kept parallel;

when the projection device is in use, after the teacher rotates the supporting rod to the vertical position, the teacher presses the placing plate to enable the lifting column in the first mounting cylinder to be retracted into the first mounting cylinder, the distance between the placing plate and the fixed plate is increased, and after the distance between the placing plate and the fixed plate is increased to a proper degree, a teacher places a smart phone playing holographic videos on a placing plate, then slowly opens the placing plate, so that a lifting column is slowly lifted under the action of a spring I in a mounting cylinder I to drive the placing plate to be close to a fixed plate, finally, a screen of the smart phone is tightly attached to the surface, close to a supporting rod, of the fixed plate, a three-dimensional pattern is formed in an imaging device and is watched by students, the teaching purpose of the teacher is fulfilled, the teaching effect of the teacher and the learning effect of the students are improved, meanwhile, after the teaching of the teacher is finished, the teacher presses the placing plate to enable the smart phone not to be in contact with the fixed plate, the teacher takes out the smart phone, then the pressing of the placing plate is released, the placing plate returns to an initial position, then, the teacher breaks the supporting rod with hands, the supporting rod is separated from the magnetic block I, and slowly rotates to a horizontal state, so that the supporting rod and a protective cover enter, finally, the teacher covers the upper cover of the box body again to seal the box body, so as to protect the protective cover and other components and avoid damage, meanwhile, the main components of the projection device are stored in the box body, so that the projection device is convenient to store, the projection device is prevented from being damaged in the storage process and being scrapped, meanwhile, in the use process, the projection device does not have a circuit part, a power supply is not required to be switched on in the use process, the teacher does not need to place the projection device at a specific position and switch on the power supply in the use process, the use of the teacher is convenient, meanwhile, the projection device does not have the circuit part, the possibility that the projection device cannot be used due to faults caused by the circuit part in the use and storage processes of the projection device can be effectively reduced, so that the service life of the projection device is prolonged, and meanwhile, the supporting rod and the protective cover, the difficulty that projection arrangement removed and carried can be reduced, the teacher of being convenient for carries projection arrangement to the classroom before the teaching in.

Preferably, a fresnel lens is fixedly mounted on the inner side surface of the protective cover; the Fresnel lens and the protective cover are bonded by epoxy resin, and tiny bubbles do not exist between the Fresnel lens and the protective cover after bonding; the epoxy resin has good transparency after being cured, and the refractive index is equal to or close to that of the materials for manufacturing the protective cover and the Fresnel lens; the protective cover and the Fresnel lens are made of the same material;

the during operation, the student is when watching the stereographic image that imaging device in the projection arrangement shows, through the fresnel lens who bonds in the inboard of protection casing, the stereographic image that shows among the imaging device can effectually be enlargied, thereby make things convenient for the student to watch, the stereographic image that forms is less in avoiding imaging device, the student far away relative projection arrangement position can not be clear watch the stereographic image that projection arrangement formed, and simultaneously, adopt fresnel lens as the thickness that the magnifying glass can effectual reduction lens, under the prerequisite of guaranteeing the enlarged effect, reduce weight, be convenient for carrying of projection arrangement, and simultaneously, bond fresnel lens can effectually avoid lens to receive external dust pollution in the use in the protection casing inboard, be difficult to clear up, lead to the lens definition to reduce, influence the student and watch the stereographic image.

Preferably, the supporting rod is a telescopic rod; the supporting rod comprises a fixed rod and an extension rod; the rotating shaft is fixedly arranged on the fixed rod; the extension rod is provided with a cavity; the fixed rod is inserted into the cavity of the extension rod, and the fixed rod and the extension rod are kept relatively fixed by friction force;

the during operation, when the teacher uses projection arrangement to show the stereomodel, the teacher breaks the bracing piece off with the fingers and thumb, make the bracing piece rotate behind the vertical state, the teacher is according to the actual conditions in the classroom, the pulling extension bar, the height of adjustment bracing piece, thereby make imaging device's highly suitable, most students watch in the suitable teacher, promote the student and watch the effect of calculus stereomodel, promote teacher's teaching effect, and simultaneously, regard as the bracing piece through using the telescopic link, can further reduce the bracing piece and rotate behind the horizontal position, the space that bracing piece and fixed mounting occupy at the protection casing on the bracing piece, reduce the volume of box, be convenient for projection arrangement's removal and carry.

Preferably, the placing plate is fixedly provided with a transverse fixing mechanism and a longitudinal fixing mechanism; the two groups of transverse fixing mechanisms are respectively positioned at two ends of the placing plate in the length direction; the two groups of transverse fixing mechanisms on the placing plate are mirror images; the two longitudinal fixing mechanisms are respectively positioned at two ends of the placing plate in the width direction; the two groups of longitudinal fixing mechanisms on the placing plate are mirror images; the intelligent mobile phone is fixedly arranged on the placing plate through the transverse fixing mechanism and the longitudinal fixing mechanism, and the intersection point of the central lines in the length direction and the width direction of the intelligent mobile phone is positioned on the central line of the supporting rod; when the smart phone is fixed on the placing plate and is close to the fixing plate, the transverse fixing mechanism and the longitudinal fixing mechanism are not in contact with the fixing plate; the transverse fixing mechanism and the longitudinal fixing mechanism are not contacted with each other;

the transverse fixing mechanism comprises a first mounting frame; the first mounting rack is fixedly mounted on the side surface of the placing plate; a second mounting cylinder is fixedly mounted on the first mounting frame; the opening of the second mounting cylinder faces the direction of the placing plate; a second spring is fixedly arranged in the second mounting cylinder; a first ejection rod is arranged in the mounting cylinder II in a sliding manner; the distance between the second spring and the placing plate is larger than the distance between the first ejection rod and the placing plate; one end of the first ejection rod, which is close to the placing plate, is fixedly provided with a first contact plate, and the first contact plate are perpendicular to each other; the first contact plate contacts and presses the smart phone placed on the placing plate;

the longitudinal fixing mechanism comprises a second mounting frame; the second mounting rack is fixedly mounted on the side surface of the placing plate; the opening of the third mounting cylinder faces the direction of the placing plate; a third spring is fixedly arranged in the third mounting cylinder; a second ejection rod is arranged in the third mounting cylinder in a sliding manner; the distance between the third spring and the placing plate is larger than the distance between the second ejection rod and the placing plate; one end of the second ejection rod, which is close to the placing plate, is fixedly provided with a second contact plate; the contact plate II contacts and presses the smart phone placed on the placing plate;

when the intelligent mobile phone fixing device works, after a teacher moves a placing board to a proper position, the intelligent mobile phone playing a holographic video is placed on the side surface, facing a fixed plate, of the placing board, meanwhile, the intelligent mobile phone is fixed on the placing board through a transverse fixing mechanism and a longitudinal fixing mechanism on the placing board, the problem that the teaching aid is accidentally touched by the teacher in the placing process or the using process of the teaching aid is avoided, so that a projection device shakes to enable the intelligent mobile phone to fall down, the intelligent mobile phone is damaged, and loss is caused is avoided, meanwhile, the transverse fixing mechanism and the longitudinal fixing mechanism are respectively arranged on the placing board in a mirror image mode, after the intelligent mobile phone is placed on the placing board and is fixed through the transverse fixing mechanism and the longitudinal regulating mechanism, under the action of the transverse fixing mechanism and the longitudinal regulating mechanism, after the intelligent mobile phone is stable in position, the intelligent mobile phone is located at the middle position on the placing, the display effect of the three-dimensional image formed in the imaging device is improved, the situation that the position where the smart phone is placed is deviated is avoided, the display effect of the three-dimensional image formed in the imaging device is poor, the teacher is required to adjust repeatedly, the teaching time of the teacher is wasted, and the teaching effect of the teacher is reduced.

Preferably, the placement plate is made of metal having good thermal conductivity; fins are fixedly arranged on the side surface of the placing plate close to the supporting rod; the end surface of the support rod close to the fixed plate is fixedly provided with a buffer body; the buffer body is made of rubber materials and is cylindrical; the height of the buffer body is greater than that of the fins;

the during operation, the back of placing the board is provided with the fin, can be effectual with the heat transfer that produces when the smart mobile phone broadcast holographic video, give off and walk, guarantee the organism temperature relatively stable of smart mobile phone, avoid at teacher's teaching in-process, because the time is longer, lead to the smart mobile phone after long-time broadcast holographic video, organism high temperature, influence the life of smart mobile phone, and simultaneously, the buffering body that sets up on the bracing piece presses down at the teacher and places the board, enlarge the space of placing between board and the fixed plate, thereby be convenient for the in-process that the smart mobile phone placed, to placing the board and cushion, block, avoid under the unexpected condition, the teacher is too big hard, lead to placing the terminal surface that the board struck the bracing piece, arouse to place the fin deformation or the damage at the board back.

Preferably, the bottom surface of the box body is fixedly provided with a mounting seat; an air bag is fixedly arranged in the mounting seat; the air bag is fixedly provided with a one-way valve, and outside air enters the air bag in a one-way mode; the supporting rod is internally provided with a mounting hole; an air pipe is fixedly arranged in the mounting hole; one end of the air pipe is fixedly connected to the air bag; the air pipe is provided with a one-way valve, and air enters the air pipe from the air bag in a one-way mode; a cleaning ring is fixedly arranged on the side surface of the fixed plate; a communicating hole is formed in the cleaning ring; the other end of the air pipe is fixedly connected to the cleaning ring, and the air pipe is communicated with the communicating hole; the side surface of the cleaning ring facing the protective cover is provided with micropores; an included angle is formed between the micropore and the plane where the side face of the protective cover is located, and the center line of the micropore penetrates through the plane where the side face of the protective cover is located; when the supporting rod is in a vertical state, the air bag is not in contact with the supporting rod, and the volume of the air bag is in a maximum state; in the process that the supporting rod is changed into the horizontal state from the vertical state, the air bag is extruded by the supporting rod; when the supporting rod is in a horizontal state, the supporting rod extrudes the air bag, and the volume of the air bag is in a minimum state; a fixed frame is fixedly arranged on the mounting seat; a second magnetic block is fixedly arranged on the fixed frame; a third magnetic block is fixedly arranged on the side surface of the support rod; when the supporting rod is in a horizontal state, the second magnetic block and the third magnetic block are mutually contacted and mutually fixed through the action of magnetic force;

when the teaching device works, a teacher uses the projection device to display a three-dimensional image, when teaching is carried out, the teacher manually rotates the supporting rod to enable the supporting rod to be changed into a vertical state from a horizontal state, meanwhile, in the process that the supporting rod rotates to the vertical state, the supporting rod is gradually far away from the air bag, the air bag is not continuously extruded, so that the volume inside the air bag is gradually enlarged, the air bag sucks outside air into the space inside the air bag through the check valve under the action of the external atmospheric pressure, meanwhile, in the process that the volume of the air bag is enlarged, the air bag generates certain extrusion force on the supporting rod, the rotating speed of the supporting rod is accelerated, the force required by the teacher to rotate the supporting rod is reduced, meanwhile, in the using process, when the teacher does not need to use the projection device to display the three-dimensional image for teaching any more, the teacher firstly takes, and the support rod is rotated to enable the support rod to be changed from a vertical state to a horizontal state, meanwhile, in the process that the support rod rotates to the horizontal position, the support rod extrudes the air bag to reduce the volume of the air bag, the pressure in the air bag is increased, and the gas in the air bag is discharged through the air pipe, meanwhile, in the process that the support rod rotates to the horizontal position, the air bag has a buffer effect on the support rod to prevent the support rod from rapidly falling to the horizontal position to cause the collision between the protective cover fixedly arranged on the support rod and the bottom surface of the box body to cause the damage of the protective cover, meanwhile, after the support rod rotates to the horizontal position, the magnetic block III on the support rod is mutually contacted with the magnetic block II arranged on the fixing frame, magnetism exists between the magnetic block III and the magnetic block III, so that after the support rod rotates to the horizontal position, avoid when removing or carrying projection arrangement, the bracing piece does not receive fixedly in the box, make the bracing piece appear rocking in the box, the collision, arouse projection arrangement to damage, and simultaneously, install the clean ring in the fixed plate side, rotate horizontal position's in-process at the bracing piece, gas after the pressure rise in the gasbag passes through the trachea and carries in the intra-annular intercommunicating pore of clean ring, and simultaneously, it spouts through the micropore on the clean ring to enter into the intra-annular gas of clean ring, thereby at the in-process of packing up bracing piece and protection casing, can be through spun gas, blow the dust on the side all around the protection casing clean, avoid external dust to cause the influence to the protection casing, it is serious to the wearing and tearing of protection casing surface to avoid the accumulated dust, influence the transparency of.

The invention has the following beneficial effects:

1. according to the calculus model stereoscopic projection system for college and university mathematics teaching, a teacher can show a mathematical calculus model to students in the teaching process by using the smart phone and the projection device, the cognition of the students on calculus is improved, the teaching effect is improved, meanwhile, the teacher can log in a service platform by using the smart phone and can randomly select different types and numbers of calculus models to play, the understanding of the students is deepened, meanwhile, the projection stereoscopic model can be more convenient and rapid by using the smart phone and the projection device to be matched, the problem that a traditional projection device is complex in operation machine is solved, meanwhile, the projection device does not relate to a circuit part, the failure rate of the projection device can be reduced, and the service life of the projection device is prolonged.

2. According to the calculus model stereoscopic projection system for the mathematics teaching in colleges and universities, disclosed by the invention, the Fresnel lens is arranged on the inner side of the protective cover, so that students can watch amplified stereoscopic images, the students can see the displayed images more clearly, meanwhile, the telescopic rod is used as the supporting rod, the occupied space of the projection device can be reduced, the size of the box body is reduced, and the projection device is convenient for teachers to move or carry and is convenient for teachers to use.

Drawings

The invention will be further explained with reference to the drawings.

FIG. 1 is a schematic diagram of a projection apparatus according to the present invention;

FIG. 2 is a schematic structural diagram of a supporting rod and a supporting plate of the projection apparatus according to the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 1 at A;

FIG. 4 is an enlarged view of a portion of FIG. 1 at B;

FIG. 5 is a system framework diagram of the present invention;

in the figure: the air bag cleaning device comprises a box body 1, an upper cover 11, a handle 12, a first magnetic block 13, a hinge base 14, a mounting base 15, an air bag 151, an air pipe 152, a fixing frame 153, a second magnetic block 154, a third magnetic block 155, a supporting rod 2, a rotating shaft 21, a fixing rod 22, a mounting hole 221, an extension rod 23, a buffer body 231, a connecting support 24, an extrusion column 25, a first spring 251, a lifting column 252, a first mounting barrel 253, a placing plate 26, a fin 261, a transverse fixing mechanism 27, a first mounting frame 271, a second mounting barrel 272, a second spring 273, a first ejection rod 274, a first contact plate 275, a longitudinal fixing mechanism 28, a second mounting frame 281, a third mounting barrel 282, a third spring 283, a second ejection rod 284, a second contact plate 285, a fixing plate 3, an imaging device 31, a protective cover 32, a Fresnel lens 321, a cleaning ring 33.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1 to 5, the calculus model stereoscopic projection system for mathematical education in colleges and universities, provided by the invention, comprises a service platform, a terminal APP and a projection device; the terminal APP is installed in a common smart phone; the terminal APP is connected with the service platform through a network and exchanges data; uploading, downloading and sharing a calculus teaching model video among the teachers through a service platform; the service platform comprises a model conversion module, a holographic video and a video processing module, wherein the model conversion module is used for converting a calculus model video uploaded by a teacher through a terminal APP into a holographic video which can be used by a projection device; the teacher uses a smart phone provided with a terminal APP to play a holographic video, places the smart phone into a projection device, and displays a stereoscopic image through the projection device;

the projection device comprises a box body 1; an upper cover 11 is hinged above the box body 1; a handle 12 is fixedly arranged in the middle of the upper surface of the upper cover 11; a hinge seat 14 is fixedly arranged on the side wall in the box body 1; a support rod 2 is arranged in the box body 1; the tail end of the support rod 2 is fixedly provided with a rotating shaft 21; the rotating shaft 21 is rotatably arranged on the hinge base 14; the top end of the telescopic rod is fixedly provided with a connecting bracket 24; one end of the connecting bracket 24, which is far away from the telescopic rod, is fixedly provided with a fixing plate 3; the imaging device 31 is fixedly arranged at the side center position of the fixing plate 3 far away from the connecting bracket 24; the imaging device 31 is a projection device described in chinese patent with application number CN 201420304344.7; the central line of the projection device in the length direction is superposed with the central line of the support rod 2; a protective cover 32 is fixedly arranged on the side surface of the fixing plate 3 far away from the connecting bracket 24; the protective cover 32 is made of a plastic material with good transparency and light weight; the protective cover 32 is square, and the projection device is positioned inside the protective cover 32; when the support rod 2 is kept in a horizontal state in the box body 1, the protective cover 32 does not contact the bottom surface of the box body 1 and the lower surface of the upper cover 11; a first magnetic block 13 is fixedly arranged on the side surface of the box body 1; when the supporting rod 2 is kept in a vertical state in the box body 1, the supporting rod 2 is adsorbed on the first magnetic block 13; when the support rod 2 is kept in a vertical state, the protective cover 32 is positioned above the box body 1, and the two are not contacted with each other;

a gap is formed between the fixing plate 3 and the top end of the supporting rod 2, and the fixing plate and the supporting rod are not in direct contact; the connecting bracket 24 is fixedly provided with an extrusion column 25; the extrusion column 25 is positioned on the connecting bracket 24 in the area vertical to the support rod 2; the extrusion column 25 comprises a first mounting barrel 253; a first spring 251 is fixedly arranged in the first mounting cylinder 253; a lifting column 252 is slidably mounted in the first mounting cylinder 253; the first spring 251 is positioned between the lifting column 252 and the bottom surface in the first mounting cylinder 253; a placing plate 26 is fixedly arranged at one end of the lifting column 252 far away from the first mounting cylinder 253; the placing plate 26 is positioned in a gap between the fixing plate 3 and the supporting rod 2; after the lifting column 252 is lifted from the first mounting cylinder 253, the placing plate 26 just contacts the side surface of the fixing plate 3 close to the supporting rod 2; the smart phone is placed on the side of the placing plate 26 close to the fixing plate 3; the intersection point of the central line in the length direction and the width direction of the placing plate 26 is positioned on the central line of the supporting rod 2; the placing plate 26 and the end surface of the support rod 2 close to the fixing plate 3 are kept parallel;

in operation, a teacher opens the upper cover 11 on the box 1 of the projection device by pulling the handle 12, and then the teacher grasps the support rod 2 with hands to rotate the support rod 2 around the rotating shaft 21, so that the support rod 2 is changed from a horizontal state to a vertical state, and the protective cover 32 is moved out of the box 1, and meanwhile, when the support rod 2 is in the vertical state, the support rod 2 is adsorbed by the first magnetic block 13 on the side wall of the box 1, so as to ensure that the position of the support rod 2 is relatively fixed, and prevent the support rod 2 from toppling over during the teaching process of the teacher using the projection group device, which causes the damage to the projection device and the smart phone placed in the projection device, and meanwhile, after the teacher rotates the support rod 2 to the vertical position during the use process, the teacher presses the placing plate 26, so that the lifting column 252 in the first mounting cylinder 253 is retracted into the first mounting cylinder 253, and the distance between the placing, after the distance between the placing plate 26 and the fixing plate 3 is increased to a proper degree, a teacher places a smart phone playing a holographic video on the placing plate 26, then slowly releases the placing plate 26, so that the lifting column 252 is slowly lifted under the action of the spring one 251 in the mounting cylinder one 253 to drive the placing plate 26 to be close to the fixing plate 3, finally, a screen of the smart phone is tightly attached to the surface of the fixing plate 3 close to the supporting rod 2, a three-dimensional pattern is formed in the imaging device 31 for the students to watch, the teaching purpose of the teacher is completed, the teaching effect of the teacher and the learning effect of the students are improved, meanwhile, after the teaching of the teacher is completed, the teacher presses the placing plate 26, so that the smart phone is not in contact with the fixing plate 3, the teacher takes out the smart phone, then, the pressing of the placing plate 26 is released, the placing plate 26 returns to the initial position, then, the teacher manually moves the supporting rod 2, the support rod 2 and the magnetic block 13 are separated from each other and slowly rotate to a horizontal state, so that the support rod 2 and the protective cover 32 enter the box body 1 again, finally, a teacher covers the upper cover 11 of the box body 1 again to seal the box body 1, so that the protective cover 32 and other components are protected and prevented from being damaged, meanwhile, the main components of the projection device are stored in the box body 1, so that the projection device is convenient to store, the projection device is prevented from being damaged in the storage process, the projection device is prevented from being scrapped, meanwhile, in the using process, the projection device does not have a circuit part, a power supply is not required to be switched on in the using process, the projection device does not need to be placed at a specific position and is switched on when the teacher is used, the teacher is convenient to use, meanwhile, the projection device does not have the circuit part, and faults caused by the circuit part in the using and storing process of, the possibility that the projection device cannot be used is caused, so that the service life of the projection device is prolonged, meanwhile, the supporting rod 2 and the protective cover 32 are placed in the box body 1, the moving and carrying difficulty of the projection device can be reduced, and a teacher can conveniently carry the projection device to a classroom before teaching.

As an embodiment of the present invention, a fresnel lens 321 is fixedly mounted on an inner side surface of the protective cover 32; the Fresnel lens 321 and the protective cover 32 are bonded by epoxy resin, and tiny bubbles do not exist between the Fresnel lens 321 and the protective cover after bonding; the epoxy resin has good transparency after being cured, and the refractive index is equal to or close to that of the materials for manufacturing the protective cover 32 and the Fresnel lens 321; the protective cover 32 and the Fresnel lens 321 are made of the same material;

in operation, when a student views a stereoscopic image displayed by the imaging device 31 of the projection device, the stereoscopic image displayed by the imaging device 31 can be effectively magnified by the fresnel lens 321 adhered to the inner side of the protective cover 32, thereby facilitating the viewing of students, preventing students who are far away from the projection device from being able to clearly view the stereoscopic image formed by the projection device because the stereoscopic image formed in the imaging device 31 is relatively small, meanwhile, the Fresnel lens 321 is adopted as the magnifier, so that the thickness of the lens can be effectively reduced, under the prerequisite of guaranteeing the enlarged effect, reduce weight, the carrying of the projection arrangement of being convenient for, simultaneously, bond fresnel lens 321 can effectually avoid lens to receive external dust pollution in the use in protection casing 32 inboard, be difficult to the clearance, lead to the lens definition to reduce, influence the student and watch the stereoimage.

As an embodiment of the present invention, the support rod 2 is a telescopic rod; the support rod 2 comprises a fixed rod 22 and an extension rod 23; the rotating shaft 21 is fixedly arranged on the fixing rod 22; the extension rod 23 is provided with a cavity; the fixed rod 22 is inserted into a cavity on the extension rod 23, and the fixed rod 22 and the extension rod 23 are kept relatively fixed by friction;

the during operation, when the teacher uses projection arrangement to show the stereomodel, the teacher breaks bracing piece 2 off with the fingers and thumb, make bracing piece 2 rotate behind the vertical state, the teacher is according to the actual conditions in the classroom, pulling extension bar 23, adjust the height of bracing piece 2, thereby make imaging device 31 highly suitable, most students watch in the suitable teacher, promote the student and watch the effect of calculus stereomodel, promote teacher's teaching effect, and simultaneously, regard as bracing piece 2 through using the telescopic link, can further reduce bracing piece 2 and rotate behind the horizontal position, bracing piece 2 and the space that protective cover 32 fixed mounting on bracing piece 2 occupied, reduce the volume of box 1, be convenient for projection arrangement's removal and carry.

As an embodiment of the present invention, a transverse fixing mechanism 27 and a longitudinal fixing mechanism 28 are fixedly mounted on the placing plate 26; the two groups of transverse fixing mechanisms 27 are respectively positioned at the two ends of the placing plate 26 in the length direction; the two groups of transverse fixing mechanisms 27 on the placing plate 26 are mirror images of each other; the longitudinal fixing mechanisms 28 are divided into two groups, and are respectively positioned at two ends of the placing plate 26 in the width direction; the two sets of longitudinal fixing mechanisms 28 on the placing plate 26 are mirror images of each other; the smart phone is fixedly kept on the placing plate 26 through the transverse fixing mechanism 27 and the longitudinal fixing mechanism 28, and the intersection point of the central lines in the length direction and the width direction of the smart phone is positioned on the central line of the support rod 2; when the smart phone is fixed on the placing plate 26 and is close to the fixing plate 3, the transverse fixing mechanism 27 and the longitudinal fixing mechanism 28 do not contact the fixing plate 3; the transverse fixing mechanism 27 and the longitudinal fixing mechanism 28 are not contacted with each other;

the transverse fixing mechanism 27 comprises a first mounting frame 271; the first mounting frame 271 is fixedly mounted on the side surface of the placing plate 26; a second mounting cylinder 272 is fixedly mounted on the first mounting frame 271; the opening of the second mounting tube 272 faces the direction of the placing plate 26; a second spring 273 is fixedly arranged in the second mounting cylinder 272; a first ejection rod 274 is slidably arranged in the second mounting cylinder 272; the distance between the second spring 273 and the placing plate 26 is larger than the distance between the first ejector rod 274 and the placing plate 26; one end of the first ejection rod 274, close to the placing plate 26, is fixedly provided with a first contact plate 275, and the two contact plates are vertical to each other; the first contact plate 275 contacts and presses the smart phone placed on the placing plate 26;

the longitudinal fixing mechanism 28 comprises a second mounting rack 281; the second mounting rack 281 is fixedly arranged on the side surface of the placing plate 26; the opening of the third mounting cylinder 282 faces the direction of the placing plate 26; a third spring 283 is fixedly arranged in the third mounting cylinder 282; a second ejection rod 284 is slidably mounted in the third mounting cylinder 282; the distance between the third spring 283 and the placing plate 26 is larger than the distance between the second ejector rod 284 and the placing plate 26; a second contact plate 285 is fixedly installed at one end, close to the placing plate 26, of the second ejection rod 284; the second contact plate 285 contacts and presses the smart phone placed on the placing plate 26;

in operation, after the teacher moves the placing board 26 to a suitable position, the smartphone playing the holographic video is placed on the side surface of the placing board 26 facing the fixing board 3, meanwhile, the smartphone is fixed on the placing board 26 through the transverse fixing mechanism 27 and the longitudinal fixing mechanism 28 on the placing board 26, so that the problem that the teaching aid is accidentally touched by the teacher in the placing process or the teaching aid using process, the projection device shakes to drop the smartphone, the smartphone is damaged to cause loss is avoided, meanwhile, because the transverse fixing mechanism 27 and the longitudinal fixing mechanism 28 are respectively arranged on the placing board 26 in a mirror image manner, after the smartphone is placed on the placing board 26 and fixed through the transverse fixing mechanism 27 and the longitudinal regulating mechanism, under the action of the transverse fixing mechanism 27 and the longitudinal regulating mechanism, the smartphone is located at the middle position on the placing board 26 after the smartphone is stable in position, the screen center position of the smartphone coincides with the center of the imaging device 31, the display effect of the formed three-dimensional image in the imaging device 31 is improved, the situation that the placement position of the smart phone is deviated, the display effect of the formed three-dimensional image in the imaging device 31 is poor, a teacher needs to adjust repeatedly, the teaching time of the teacher is wasted, and the teaching effect of the teacher is reduced.

As an embodiment of the present invention, the placement plate 26 is made of metal having good thermal conductivity; fins 261 are fixedly arranged on the side surface of the placing plate 26 close to the support rod 2; a buffer body 231 is fixedly arranged on the end surface of the support rod 2 close to the fixed plate 3; the buffer body 231 is made of rubber material and is cylindrical; the height of the buffer body 231 is greater than that of the fins 261;

the during operation, be provided with fin 261 at the back of placing board 26, can be effectual with the heat transfer that produces when the smart mobile phone broadcast holographic video, give off, guarantee the organism temperature relatively stable of smart mobile phone, avoid at teacher's teaching in-process, because the time is longer, lead to the smart mobile phone after long-time broadcast holographic video, organism temperature is too high, influence the life of smart mobile phone, and simultaneously, buffer 231 who sets up on bracing piece 2 presses at the teacher and places board 26, enlarge the space of placing between board 26 and the fixed plate 3, thereby be convenient for the in-process that the smart mobile phone placed, to placing board 26 and buffering, block, avoid unexpected under the condition, the teacher is too big hard, lead to placing the terminal surface that board 26 struck bracing piece 2, cause the fin 261 of placing the board 26 back to warp or damage.

As an embodiment of the present invention, a mounting seat 15 is fixedly mounted on the bottom surface of the box body 1; an air bag 151 is fixedly arranged in the mounting seat 15; a one-way valve is fixedly arranged on the air bag 151, and outside air enters the air bag 151 in a one-way mode; a mounting hole 221 is formed in the support rod 2; an air pipe 152 is fixedly arranged in the mounting hole 221; one end of the air tube 152 is fixedly connected to the air bag 151; the air pipe 152 is provided with a one-way valve, and air enters the air pipe 152 from the air bag 151 in one way; a cleaning ring 33 is fixedly arranged on the side surface of the fixed plate 3; a communicating hole 331 is formed in the cleaning ring 33; the other end of the air pipe 152 is fixedly connected to the cleaning ring 33, and the air pipe 152 is communicated with the communication hole 331; the side surface of the cleaning ring 33 facing the protective cover 32 is provided with micropores 332; an included angle is formed between the micropore 332 and the plane of the side face of the protective cover 32, and the center line of the micropore 332 penetrates through the plane of the side face of the protective cover 32; when the support rod 2 is in a vertical state, the air bag 151 is not in contact with the support rod 2, and the volume of the air bag 151 is in a maximum state; in the process that the supporting rod 2 is changed from the vertical state to the horizontal state, the air bag 151 is extruded by the supporting rod 2; when the support rod 2 is in a horizontal state, the support rod 2 extrudes the air bag 151, and the volume of the air bag 151 is in a minimum state; a fixing frame 153 is fixedly arranged on the mounting seat 15; a second magnetic block 154 is fixedly arranged on the fixing frame 153; a magnetic block III 155 is fixedly arranged on the side surface of the support rod 2; when the support rod 2 is in a horizontal state, the second magnetic block 154 and the third magnetic block 155 are mutually contacted and fixed through the magnetic force;

when the teaching aid works, a teacher displays a stereoscopic image by using the projection device, when teaching, the teacher manually rotates the supporting rod 2 to enable the supporting rod 2 to be changed into a vertical state from a horizontal state, meanwhile, in the process that the supporting rod 2 rotates to the vertical state, the supporting rod 2 is gradually far away from the air bag 151 and does not continuously extrude the air bag 151, so that the volume inside the air bag 151 is gradually enlarged, the air bag 151 sucks outside air into the space inside the air bag 151 through a one-way valve under the action of atmospheric pressure, meanwhile, in the process that the volume of the air bag 151 is enlarged, the air bag 151 generates certain extrusion force on the supporting rod 2, the rotating speed of the supporting rod 2 is increased, the force required by the teacher to rotate the supporting rod 2 is reduced, meanwhile, in the using process, after the teacher does not need to use the projection device to display the stereoscopic image for teaching, then, the extension bar 23 is pressed back into the fixing bar 22, the support bar 2 is rotated to change the support bar 2 from the vertical state to the horizontal state, meanwhile, in the process that the support bar 2 rotates back to the horizontal state, the support bar 2 extrudes the air bag 151 to reduce the volume of the air bag 151, the pressure in the air bag 151 is increased, and the gas in the air bag 151 is exhausted through the air pipe 152, meanwhile, in the process that the support bar 2 rotates to the horizontal position, the air bag 151 generates a buffer effect on the support bar 2 to prevent the support bar 2 from rapidly falling to the horizontal position, so that the protective cover 32 fixedly installed on the support bar 2 collides with the bottom surface of the box body 1 to cause the damage of the protective cover 32, meanwhile, after the support bar 2 rotates to the horizontal position, the magnetic block three 155 on the support bar 2 is in contact with the magnetic block two 154 installed on the, therefore, after the support rod 2 rotates to the horizontal position, the support rod 2 is relatively fixed through the action of the second magnetic block 154 and the third magnetic block 155, and the damage of the projection device caused by the shaking and collision of the support rod 2 in the box body 1 is avoided when the projection device is moved or carried, meanwhile, the cleaning ring 33 installed on the side surface of the fixed plate 3 is avoided, in the process that the support rod 2 rotates to the horizontal position, the gas with the increased pressure in the air bag 151 is conveyed to the communication hole 331 in the cleaning ring 33 through the air pipe 152, and meanwhile, the gas entering the cleaning ring 33 is sprayed out through the micropores 332 on the cleaning ring 33, so that in the process of retracting the support rod 2 and the protective cover 32, the dust on the side surface around the protective cover 32 can be blown clean through the sprayed gas, and the influence of the external dust on the protective cover 32 is avoided, the accumulated dust is prevented from reaching the surface of the protective cover 32, so that the surface is seriously abraded, and the transparency of the protective cover 32 is influenced.

The specific working process is as follows:

when the projection device works, a teacher opens the upper cover 11 on the box body 1 of the projection device by pulling the handle 12, then the teacher grasps the support rod 2 by hand, rotates the support rod 2 around the rotating shaft 21, so that the support rod 2 is changed from a horizontal state to a vertical state, and the protective cover 32 is moved out of the box body 1, meanwhile, when the support rod 2 is in the vertical state, the support rod 2 is adsorbed by the first magnetic block 13 on the side wall of the box body 1, meanwhile, in the using process, after the teacher rotates the support rod 2 to the vertical position, the teacher presses the placing plate 26, so that the lifting column 252 in the first mounting cylinder 253 is retracted into the first mounting cylinder 253, the distance between the placing plate 26 and the fixing plate 3 is increased, the teacher places a smart phone playing a holographic video on the placing plate 26, and then slowly releases the placing plate 26, so that the lifting column 252 is slowly lifted under the action of the first spring 251 in the first mounting cylinder 253, driving the placing plate 26 to be close to the fixed plate 3, finally enabling a screen of the smart phone to be tightly attached to the surface, close to the supporting rod 2, of the fixed plate 3, meanwhile, after the teacher finishes teaching, the teacher presses the placing plate 26 to enable the smart phone not to be in contact with the fixed plate 3, the teacher takes out the smart phone, then releases the pressing on the placing plate 26 to enable the placing plate 26 to return to the initial position, then the teacher breaks the supporting rod 2 with hands to enable the supporting rod 2 and the magnetic block I13 to be separated from each other and slowly rotate to the horizontal state, so that the supporting rod 2 and the protective cover 32 enter the box body 1 again, and finally, the teacher covers the upper cover 11 of the box body 1 again to seal the box body 1; when a student views the stereoscopic image displayed by the imaging device 31 in the projection device, the stereoscopic image displayed in the imaging device 31 is magnified by the fresnel lens 321 bonded to the inside of the shield 32; when a teacher uses the projection device to display a three-dimensional model, the teacher breaks the support rod 2 to enable the support rod 2 to rotate to be in a vertical state, and then the teacher pulls the extension rod 23 to adjust the height of the support rod 2 according to the actual situation in a classroom, so that the height of the imaging device 31 is proper and the imaging device is suitable for most students in the teacher to watch; after the teacher moves the placing board 26 to a proper position, the smartphone playing the holographic video is placed on the placing board 26 towards the side surface of the fixing board 3, meanwhile, the smartphone is fixed on the placing board 26 through the transverse fixing mechanism 27 and the longitudinal fixing mechanism 28 on the placing board 26, and after the smartphone is stabilized in position, the smartphone is located in the middle position on the placing board 26, so that the center position of the screen of the smartphone coincides with the center of the imaging device 31; the fins 261 are arranged on the back of the placing plate 26, so that heat generated when the smartphone plays a holographic video is transferred and dissipated, meanwhile, the buffer body 231 is arranged on the supporting rod 2, and the placing plate 26 is buffered and blocked in the process that a teacher presses the placing plate 26; in the process that the support rod 2 rotates to the vertical state, the support rod 2 is gradually far away from the air bag 151, the air bag 151 is not continuously extruded, so that the volume inside the air bag 151 is gradually enlarged, the air bag 151 sucks external air into the inner space of the air bag 151 through the one-way valve under the action of external atmospheric pressure, meanwhile, after a teacher does not need to use a projection device to display a stereoscopic image for teaching, the teacher takes off the smart phone first, then presses the extension rod 23 back into the fixing rod 22 and rotates the support rod 2, so that the support rod 2 is changed from the vertical state to the horizontal state, meanwhile, in the process that the support rod 2 rotates back to the horizontal position, the support rod 2 extrudes the air bag 151, so that the volume of the air bag 151 is reduced, the pressure inside the air bag 151 is increased, the air inside the air bag 151 is discharged through the air pipe 152, and meanwhile, after the, the magnetic block three 155 on the support rod 2 is in contact with the magnetic block two 154 mounted on the fixing frame 153, magnetism exists between the two, the support rod 2 is relatively fixed, and meanwhile, the gas with the increased pressure in the air bag 151 is conveyed to the communicating hole 331 in the cleaning ring 33 through the air pipe 152 and is sprayed out through the micropores 332 on the cleaning ring 33.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a college mathematics teaching is with calculus model stereoscopic projection system which characterized in that: the system comprises a service platform, a terminal APP and a projection device; the terminal APP is installed in a common smart phone; the terminal APP is connected with the service platform through a network and exchanges data; uploading, downloading and sharing a calculus teaching model video among the teachers through a service platform; the service platform comprises a model conversion module, a holographic video and a video processing module, wherein the model conversion module is used for converting a calculus model video uploaded by a teacher through a terminal APP into a holographic video which can be used by a projection device; the teacher uses a smart phone provided with a terminal APP to play a holographic video, places the smart phone into a projection device, and displays a stereoscopic image through the projection device;

the projection device comprises a box body (1); an upper cover (11) is hinged above the box body (1); a handle (12) is fixedly arranged in the middle of the upper surface of the upper cover (11); a hinge seat (14) is fixedly arranged on the side wall in the box body (1); a support rod (2) is arranged in the box body (1); the tail end of the support rod (2) is fixedly provided with a rotating shaft (21); the rotating shaft (21) is rotatably arranged on the hinge seat (14); a connecting bracket (24) is fixedly arranged at the top end of the telescopic rod; a fixing plate (3) is fixedly arranged at one end of the connecting bracket (24) far away from the telescopic rod; an imaging device (31) is fixedly arranged at the side center position of the fixing plate (3) far away from the connecting bracket (24); the imaging device (31) is a projection device described in Chinese patent with application number CN 201420304344.7; the central line of the projection device in the length direction is superposed with the central line of the support rod (2); a protective cover (32) is fixedly arranged on the side surface of the fixing plate (3) far away from the connecting bracket (24); the protective cover (32) is made of plastic materials with good transparency and light weight; the protective cover (32) is square, and the projection device is positioned inside the protective cover (32); when the supporting rod (2) is kept in a horizontal state in the box body (1), the protective cover (32) is not contacted with the bottom surface of the box body (1) and the lower surface of the upper cover (11); a first magnetic block (13) is fixedly arranged on the side surface of the box body (1); when the supporting rod (2) is kept in a vertical state in the box body (1), the supporting rod (2) is adsorbed on the first magnetic block (13); when the supporting rod (2) is kept in a vertical state, the protective cover (32) is positioned above the box body (1) and is not contacted with each other;

a gap is formed between the fixed plate (3) and the top end of the supporting rod (2), and the fixed plate and the supporting rod are not in direct contact; an extrusion column (25) is fixedly arranged on the connecting bracket (24); the extrusion columns (25) are positioned on the connecting bracket (24) and in the area vertical to the support rod (2); the extrusion column (25) comprises a first mounting barrel (253); a first spring (251) is fixedly arranged in the first mounting cylinder (253); a lifting column (252) is arranged in the first mounting cylinder (253) in a sliding manner; the first spring (251) is positioned between the lifting column (252) and the bottom surface in the first mounting cylinder (253); a placing plate (26) is fixedly arranged on one end, far away from the first mounting cylinder (253), of the lifting column (252); the placing plate (26) is positioned in a gap between the fixing plate (3) and the supporting rod (2); after the lifting column (252) is lifted from the first mounting cylinder (253), the placing plate (26) just contacts the side surface of the fixing plate (3) close to the supporting rod (2); the smart phone is placed on the side face, close to the fixing plate (3), of the placing plate (26); the intersection point of the middle lines of the placing plate (26) in the length direction and the width direction is positioned on the central line of the supporting rod (2); the placing plate (26) and the end face of the supporting rod (2) close to the fixing plate (3) are kept parallel.

2. The calculus model stereoscopic projection system for college mathematics teaching of claim 1, wherein: a Fresnel lens (321) is fixedly arranged on the inner side surface of the protective cover (32); the Fresnel lens (321) and the protective cover (32) are bonded by epoxy resin, and tiny bubbles do not exist between the Fresnel lens and the protective cover after bonding; the epoxy resin has good transparency after being cured, and the refractive index is equal to or close to that of the materials for manufacturing the protective cover (32) and the Fresnel lens (321); the protective cover (32) and the Fresnel lens (321) are made of the same material.

3. The calculus model stereoscopic projection system for college mathematics teaching of claim 1, wherein: the supporting rod (2) is a telescopic rod; the supporting rod (2) comprises a fixing rod (22) and an extension rod (23); the rotating shaft (21) is fixedly arranged on the fixing rod (22); the extension rod (23) is provided with a cavity; the fixing rod (22) is inserted into a cavity on the extension rod (23), and the fixing rod (22) and the extension rod (23) are kept relatively fixed by friction.

4. The calculus model stereoscopic projection system for college mathematics teaching of claim 1, wherein: a transverse fixing mechanism (27) and a longitudinal fixing mechanism (28) are fixedly arranged on the placing plate (26); the two groups of transverse fixing mechanisms (27) are respectively positioned at two ends of the placing plate (26) in the length direction; the two groups of transverse fixing mechanisms (27) on the placing plate (26) are mirror images of each other; the longitudinal fixing mechanisms (28) are divided into two groups and are respectively positioned at the two ends of the placing plate (26) in the width direction; the two groups of longitudinal fixing mechanisms (28) on the placing plate (26) are mirror images of each other; the smart phone is fixedly kept on the placing plate (26) through the transverse fixing mechanism (27) and the longitudinal fixing mechanism (28), and the intersection point of the central lines in the length direction and the width direction of the smart phone is positioned on the central line of the supporting rod (2); when the placing plate (26) is fixed with a smart phone and is close to the fixing plate (3), the transverse fixing mechanism (27) and the longitudinal fixing mechanism (28) are not in contact with the fixing plate (3); the transverse fixing mechanism (27) and the longitudinal fixing mechanism (28) are not contacted with each other;

the transverse fixing mechanism (27) comprises a first mounting frame (271); the first mounting rack (271) is fixedly arranged on the side surface of the placing plate (26); a second mounting cylinder (272) is fixedly mounted on the first mounting frame (271); the opening of the second mounting tube (272) faces the direction of the placing plate (26); a second spring (273) is fixedly arranged in the second mounting cylinder (272); a first ejection rod (274) is arranged in the second mounting cylinder (272) in a sliding manner; the distance between the second spring (273) and the placing plate (26) is larger than the distance between the first ejector rod (274) and the placing plate (26); one end of the first ejection rod (274) close to the placing plate (26) is fixedly provided with a first contact plate (275), and the first contact plate are vertical to each other; the first contact plate (275) contacts and presses the smart phone placed on the placing plate (26);

the longitudinal fixing mechanism (28) comprises a second mounting rack (281); the second mounting rack (281) is fixedly arranged on the side surface of the placing plate (26); the opening of the third mounting cylinder (282) faces the direction of the placing plate (26); a third spring (283) is fixedly arranged in the third mounting cylinder (282); a second ejection rod (284) is arranged in the third mounting cylinder (282) in a sliding manner; the distance between the third spring (283) and the placing plate (26) is larger than the distance between the second ejector rod (284) and the placing plate (26); a second contact plate (285) is fixedly installed at one end, close to the placing plate (26), of the second ejection rod (284); the second contact plate (285) contacts and presses the smart phone placed on the placing plate (26).

5. The calculus model stereoscopic projection system for college mathematics teaching of claim 1, wherein: the placement plate (26) is made of metal having good thermal conductivity; fins (261) are fixedly arranged on the side surface of the placing plate (26) close to the support rod (2); a buffer body (231) is fixedly arranged on the end surface of the support rod (2) close to the fixed plate (3); the buffer body (231) is made of rubber materials and is cylindrical; the height of the buffer body (231) is greater than that of the fin (261).

6. The calculus model stereoscopic projection system for college mathematics teaching of claim 1, wherein: a mounting seat (15) is fixedly arranged on the bottom surface of the box body (1); an air bag (151) is fixedly arranged in the mounting seat (15); a one-way valve is fixedly arranged on the air bag (151), and outside air enters the air bag (151) in a one-way mode; a mounting hole (221) is formed in the support rod (2); an air pipe (152) is fixedly arranged in the mounting hole (221); one end of the air pipe (152) is fixedly connected to the air bag (151); the air pipe (152) is provided with a one-way valve, and air enters the air pipe (152) from the air bag (151) in a one-way mode; a cleaning ring (33) is fixedly arranged on the side surface of the fixed plate (3); a communicating hole (331) is formed in the cleaning ring (33); the other end of the air pipe (152) is fixedly connected to the cleaning ring (33), and the air pipe (152) is communicated with the communication hole (331); the side surface of the cleaning ring (33) facing the protective cover (32) is provided with micropores (332); an included angle is formed between the micropore (332) and the plane of the side face of the protective cover (32), and the center line of the micropore (332) passes through the plane of the side face of the protective cover (32); when the supporting rod (2) is in a vertical state, the air bag (151) is not in contact with the supporting rod (2), and the volume of the air bag (151) is in a maximum state; in the process that the supporting rod (2) is changed from a vertical state to a horizontal state, the air bag (151) is extruded by the supporting rod (2); when the supporting rod (2) is in a horizontal state, the supporting rod (2) extrudes the air bag (151), and the volume of the air bag (151) is in a minimum state; a fixed frame (153) is fixedly arranged on the mounting seat (15); a second magnetic block (154) is fixedly arranged on the fixed frame (153); a third magnetic block (155) is fixedly arranged on the side surface of the support rod (2); when the supporting rod (2) is in a horizontal state, the second magnetic block (154) and the third magnetic block (155) are in mutual contact and are fixed mutually through magnetic force.