Projection imaging method and projection system

Abstract

The application provides a projection imaging method and a projection system, and relates to the technical field of medical imaging.The projection imaging method comprises the following steps: S1, acquiring a projection distance between a zoom projection lens and a to-be-projected surface; S2, obtaining a target divergence angle value of outcoming light of the zoom projection lens according to the projection distance and a preset projection image size; and S3, adjusting the divergence angle value of the outcoming light of the zoom projection lens to be equal to the target divergence angle value.Under the condition that the preset projection image size and the projection distance between the to-be-projected surface are certain, the target divergence angle value of the outcoming light of the zoom projection lens can be obtained through geometric calculation, then the zoom projection lens is adjusted according to the target divergence angle value, so that the divergence angle value of the outcoming light of the zoom projection lens is equal to the target divergence angle value, and then the size of the projection image projected onto the to-be-projected surface is the preset size.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical imaging, in particular to a projection imaging method and a projection system. BACKGROUND

[0002] In a clinical operation of tumor resection in neurosurgery, it is necessary to mark a target point (a tumor site) of a patient before operation and determine an opening position.

[0003] In a neuro-navigation product on the market, a doctor judges a lesion as follows: under the condition of combining an instrument with preoperative MRI, CT and other image conditions of a patient, the doctor is required to gradually contact a specific position of the patient's body by using a navigation pen, so that the image of the instrument and the coordinate system of the patient are coincided to complete registration; after completing the registration, the doctor can align the real surface position of the patient with the image position by using the instrument, so as to determine a surgical approach area and a mode and mark the patient's surface for registration.

[0004] In the positioning process, the doctor contacts the patient's skin by using the navigation pen, and obtains the accurate position aligned at this time from the display screen; in the use process, the doctor needs to constantly compare the corresponding influence positions under different contact positions, which is very troublesome and cannot intuitively display the image information of the patient. SUMMARY

[0005] The present application aims to provide a projection imaging method and a projection system to alleviate the technical problem that the doctor is troublesome and cannot intuitively display the image information of the patient in the existing operation.

[0006] In a first aspect, a projection imaging method provided by an embodiment of the present application includes the following steps:

[0007] S1. Obtain a projection distance between a zoom projection lens and a to-be-projected surface;

[0008] S2. Obtain a target divergence angle value of outgoing light of the zoom projection lens according to the projection distance and a size of a preset projection image;

[0009] S3. Adjust the divergence angle value of the outgoing light of the zoom projection lens to be equal to the target divergence angle value.

[0010] Further, the shape of the preset projection image is a square.

[0011] Further, the zoom projection lens includes a compensation lens group and a zoom lens group which are arranged at intervals;

[0012] In the step S3, the divergence angle of the outgoing light of the zoom projection lens is changed by changing the positions of the compensation lens group and the zoom lens group on the optical axis.

[0013] Further, the zoom projection lens further comprises a first meniscus lens located on the light-outgoing side of the variable-power lens group, the first meniscus lens comprising a light-outgoing curved surface S1 protruding towards the light-outgoing side, and a light-incoming curved surface S2 recessed towards the light-outgoing side.

[0014] Further, the variable-power lens group comprises a second meniscus lens and a double-concave lens arranged in sequence along the light-outgoing direction;

[0015] The double-concave lens comprises a light-outgoing curved surface S3 recessed towards the light-incoming side, and a light-incoming curved surface S4 recessed towards the light-outgoing side;

[0016] The second meniscus lens comprises a light-outgoing curved surface S5 recessed towards the light-incoming side, and a light-incoming curved surface S6 protruding towards the light-outgoing side.

[0017] Further, the compensation lens group comprises a plano-convex lens, a third meniscus lens and a double-convex lens arranged in sequence along the light-outgoing direction in reverse;

[0018] The double-convex lens comprises a light-outgoing curved surface S7 protruding towards the light-outgoing side, and a light-incoming curved surface S8 protruding towards the light-incoming side;

[0019] The third meniscus lens comprises a light-outgoing curved surface S9 recessed towards the light-incoming side, and a light-incoming curved surface S10 protruding towards the light-incoming side;

[0020] The plano-convex lens comprises a light-outgoing curved surface S11 protruding towards the light-outgoing side, and a light-incoming plane S12.

[0021] Further, the focal length f1 of the first meniscus lens ranges from 116mm < f1 < 118mm; the focal length f2 of the double-concave lens ranges from -19mm < f2 < -17mm; the focal length f3 of the second meniscus lens ranges from 57mm < f3 < 59mm; the focal length f4 of the double-convex lens ranges from 20mm < f4 < 22mm; the focal length f5 of the third meniscus lens ranges from -38mm < f5 < -36mm; and the focal length f6 of the plano-convex lens ranges from 39mm < f6 < 41mm.

[0022] Further, the axial distance between the light-outgoing curved surface S1 and the light-incoming curved surface S2 is greater than 4mm and less than 6mm;

[0023] The axial distance between the light-incoming curved surface S2 and the light-outgoing curved surface S3 is greater than 3mm and less than 5mm;

[0024] The axial distance between the light-outgoing curved surface S3 and the light-incoming curved surface S4 is greater than 1mm and less than 2mm;

[0025] The axial distance between the light-incoming curved surface S4 and the light-outgoing curved surface S5 is greater than 1.8mm and less than 3.8mm;

[0026] an axial distance between the light-out curve S5 and the light-in curve S6 is greater than 2.5mm and less than 4.5mm;

[0027] an axial distance between the light-out curve S7 and the light-in curve S8 is greater than 4mm and less than 6mm;

[0028] an axial distance between the light-in curve S8 and the light-out curve S9 is greater than 0.5mm and less than 1.5mm;

[0029] an axial distance between the light-out curve S9 and the light-in curve S10 is greater than 1mm and less than 2mm;

[0030] an axial distance between the light-in curve S10 and the light-out curve S11 is greater than 0.25mm and less than 0.75mm;

[0031] an axial distance between the light-out curve S11 and the light-in plane S12 is greater than 2.5mm and less than 4.5mm.

[0032] Further, the light-out curve S1 is a spherical surface, and a radius of curvature is greater than 24mm and less than 26mm;

[0033] the light-in curve S2 is a spherical surface, and a radius of curvature is greater than 35mm and less than 37mm;

[0034] the light-out curve S3 is a spherical surface, and a radius of curvature is greater than -13mm and less than -11mm;

[0035] the light-in curve S4 is a spherical surface, and a radius of curvature is greater than 76mm and less than 80mm;

[0036] the light-out curve S5 is a spherical surface, and a radius of curvature is greater than -15mm and less than -13mm;

[0037] the light-out curve S6 is a spherical surface, and a radius of curvature is greater than -12mm and less than -10mm;

[0038] the light-out curve S7 is a spherical surface, and a radius of curvature is greater than 34mm and less than 36mm;

[0039] the light-in curve S8 is a spherical surface, and a radius of curvature is greater than -20mm and less than -18mm;

[0040] the light-out curve S9 is a spherical surface, and a radius of curvature is greater than -18mm and less than -16mm;

[0041] the light-in curve S10 is a spherical surface, and a radius of curvature is greater than -40mm and less than -38mm;

[0042] The light-exiting curved surface S11 is a spherical surface, and the radius of curvature is greater than 22 mm and less than 24 mm.

[0043] In a second aspect, the embodiment of the present application provides a projection system applying the projection imaging method.

[0044] Further, the projection system comprises a housing and a first fan, the housing comprises a first side wall and a second side wall arranged on the circumferential side surface, and one end of the first side wall is connected with one end of the second side wall.

[0045] The outer side of the first side wall is provided with a plurality of first heat dissipation fins extending along the length direction thereof, and the outer side of the second side wall is provided with a plurality of second heat dissipation fins extending along the length direction thereof.

[0046] The first heat dissipation fins and the second heat dissipation fins are the same in number and one-to-one corresponding, one end of the first heat dissipation fin is connected with one end of the corresponding second heat dissipation fin.

[0047] The first fan is installed on the housing, and the first fan is located at one end of the second heat dissipation fin away from the first heat dissipation fin, and the first fan is used for blowing air to the second heat dissipation fin.

[0048] Further, the inner surface of the first side wall and the inner surface of the second side wall are both installed with a light source.

[0049] Further, the bottom surface of the light source on the first side wall is close to the inner surface of the first side wall.

[0050] The bottom surface of the light source on the second side wall is close to the inner surface of the second side wall.

[0051] Further, the bottom surface of the light source on the first side wall and the inner surface of the first side wall, and the bottom surface of the light source on the second side wall and the inner surface of the second side wall are both filled with a heat-conducting agent.

[0052] Further, the projection system further comprises a digital micromirror module and a second fan, and the digital micromirror module is installed on the back of the housing.

[0053] The digital micromirror module comprises a digital micromirror device and a heat dissipation block, the back of the digital micromirror device has a heat dissipation surface, and one end of the heat dissipation block is connected with the heat dissipation surface.

[0054] The second fan is used for blowing air to the heat dissipation block.

[0055] Further, the projection system further comprises a TIR prism located in front of the optical action surface of the digital micromirror module.

[0056] The TIR prism is located in the shell, and a third heat dissipation fin is arranged on a position corresponding to the TIR prism on the outer wall of the shell, the length direction of the third heat dissipation fin is parallel to the air outlet direction of the second fan, and the air outlet area of the second fan covers the third heat dissipation fin.

[0057] Further, a reflector is arranged between the light source and the digital micro-mirror module in the shell, a plurality of first screw holes are arranged on the side wall of the shell and penetrate the shell, an adjusting screw is threadedly connected in the first screw hole, and a second screw hole is arranged in the adjusting screw and extends along the length direction of the adjusting screw and penetrates the front and back end faces of the adjusting screw;

[0058] The back face of the reflector is provided with a positioning column corresponding to the first screw hole in a one-to-one manner; one end of the positioning column is connected with the reflector, and the other end is threadedly connected with the second screw hole;

[0059] A first spring is arranged between the shell and the reflector, one end of the first spring is connected with the shell, and the other end is connected with the reflector, and the first spring is used for pulling the reflector towards the shell or pushing the reflector away from the shell.

[0060] Further, a first internal thread is arranged on the inner wall of the first screw hole, a second internal thread is arranged on the inner wall of the second screw hole, and the screw directions of the first internal thread and the second internal thread are the same or opposite.

[0061] Further, the screw directions of the first internal thread and the second internal thread are the same, and the pitch of the first internal thread is greater than the pitch of the second internal thread.

[0062] Further, the projection system comprises a zoom projection lens, the zoom projection lens comprises a guide groove cylinder, a cam cylinder, a variable magnification lens group and a compensation lens group, the variable magnification lens group comprises a first lens holder and a first limiting pin connected with the outer wall of the first lens holder, the compensation lens group comprises a second lens holder and a second limiting pin connected with the outer wall of the second lens holder, the first lens holder and the second lens holder are located in the guide groove cylinder, the cam cylinder is sleeved on the outside of the guide groove cylinder, the cam cylinder is coaxially arranged with the guide groove cylinder, and the cam cylinder can rotate relative to the guide groove cylinder;

[0063] The guide groove cylinder is provided with a first straight line limiting groove and a second straight line limiting groove extending along the axial direction of the guide groove cylinder, and the first straight line limiting groove and the second straight line limiting groove both communicate the inner and outer walls of the guide groove cylinder; the cam cylinder is provided with a first curved sliding groove and a second curved sliding groove, and the first curved sliding groove and the second curved sliding groove both spiral along the axial direction of the cam cylinder;

[0064] The first limiting pin is located in the first linear limiting slot and the first curved sliding slot, and the second limiting pin is located in the second linear limiting slot and the second curved sliding slot, so that when the cam cylinder body rotates relative to the guide slot cylinder body, the first curved sliding slot and the second curved sliding slot can drive the variable magnification lens group and the compensation lens group to move axially, respectively.

[0065] Further, the cam cylinder body comprises a first end and a second end, the first curved sliding slot and the second curved sliding slot are sequentially arranged along the direction from the first end to the second end, and the end of the first curved sliding slot close to the first end is in communication with the end face of the first end.

[0066] Further, the cam cylinder body is provided with a mounting hole in communication with its inner and outer surfaces, the mounting hole corresponds to the second limiting pin, and the mounting hole is located at the end point of the second curved sliding slot.

[0067] Further, the zoom projection lens comprises a first driving mechanism, the first driving mechanism is mounted on the guide slot cylinder body, and the first driving mechanism is used to drive the cam cylinder body to rotate relative to the guide slot cylinder body.

[0068] Further, the cam cylinder body is provided with a first gear ring, the first driving mechanism comprises a first motor and a first gear connected with the output shaft of the first motor, and the first gear is engaged with the first gear ring.

[0069] Further, the zoom projection lens further comprises a second driving mechanism, the second driving mechanism is connected with the guide slot cylinder body, and the second driving mechanism is used to drive the guide slot cylinder body to move axially.

[0070] Further, the guide slot cylinder body is provided with a third curved sliding slot and a third linear limiting slot which are spirally curved along the axial direction of the guide slot cylinder body;

[0071] The second driving mechanism comprises a motion orientation cylinder body and a whole lens motion ring, the motion orientation cylinder body is sleeved on the outside of the guide slot cylinder body, the motion orientation cylinder body is provided with an arc-shaped sliding slot in communication with the inner and outer walls thereof, and the arc-shaped sliding slot extends along the circumferential direction of the motion orientation cylinder body;

[0072] The inner wall of the motion orientation cylinder body is provided with a third limiting pin extending inwardly, and the third limiting pin is located in the third linear limiting slot;

[0073] The whole lens motion ring is sleeved on the outside of the motion orientation cylinder body, the inner wall of the whole lens motion ring is provided with a fourth limiting pin extending inwardly, and the fourth limiting pin penetrates through the arc-shaped sliding slot and is located in the third curved sliding slot.

[0074] Further, the second driving mechanism further comprises a second gear ring arranged on the outer wall of the whole-mirror movement ring, and a second motor, an output end of the second motor being connected with a second gear, the second gear ring being engaged with the second gear.

[0075] Further, the second driving mechanism comprises a linear driving module, a linear driving end of the linear driving module being connected with the guide groove cylinder.

[0076] The projection imaging method provided by the embodiment of the present application comprises the following steps: firstly, obtaining a projection distance between a zoom projection lens and a to-be-projected surface; obtaining a target divergence angle value of the outgoing light of the zoom projection lens according to the projection distance and a preset projection image size; and finally, adjusting the divergence angle value of the outgoing light of the zoom projection lens to be equal to the target divergence angle value. In the case that the projection distance between the zoom projection lens and the to-be-projected surface is constant and the preset projection image size is constant, the target divergence angle value of the outgoing light of the zoom projection lens can be obtained through geometric calculation. Then, the zoom projection lens is adjusted according to the target divergence angle value, so that the divergence angle value of the outgoing light of the zoom projection lens is equal to the target divergence angle value. Therefore, the size of the projection image projected onto the to-be-projected surface is the preset size. That is, the change of the projection distance between the zoom projection lens and the to-be-projected surface will cause the change of the divergence angle value of the outgoing light of the zoom projection lens, so that the size of the projection image projected onto the to-be-projected surface is always constant. The preoperative image of a patient can be projected onto the patient's body according to a fixed size. Because the size of the projection image is constant, the length and width of the lineation pattern on the image are also constant, so that the doctor can directly perform lineation and surgery according to the information on the projection image. The projection imaging method can assist the doctor to complete the surgery, and the doctor does not need to repeatedly compare the information on the screen with the patient's body, so that the difficulty of the surgery can be reduced and the success rate of the surgery can be improved.

[0077] The projection system provided by the embodiment of the present application applies the projection imaging method. Because the projection system provided by the embodiment of the present application refers to the projection imaging method, the projection system provided by the embodiment of the present application also has the advantages of the projection imaging method. BRIEF DESCRIPTION OF DRAWINGS

[0078] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0079] Figure 1 The flow chart of the projection imaging method provided by the embodiment of the present application; Figure 2A schematic diagram of a projection objective applied in the projection imaging method provided by the embodiment of the present application; Figure 3 A lens imaging ray tracing diagram of the projection objective with a projection distance of 800mm in the projection imaging method provided by the embodiment of the present application; Figure 4 An optical transfer function curve diagram of the projection objective with a projection distance of 800mm in the projection imaging method provided by the embodiment of the present application; Figure 5 A distortion aberration diagram of the projection objective with a projection distance of 800mm in the projection imaging method provided by the embodiment of the present application; Figure 6 A sagittal chromatic aberration diagram of the projection objective with a projection distance of 800mm in the projection imaging method provided by the embodiment of the present application; Figure 7 A lens imaging ray tracing diagram of the projection objective with a projection distance of 1000mm in the projection imaging method provided by the embodiment of the present application; Figure 8 An optical transfer function curve diagram of the projection objective with a projection distance of 1000mm in the projection imaging method provided by the embodiment of the present application; Figure 9 A distortion aberration diagram of the projection objective with a projection distance of 1000mm in the projection imaging method provided by the embodiment of the present application; Figure 10 A sagittal chromatic aberration diagram of the projection objective with a projection distance of 1000mm in the projection imaging method provided by the embodiment of the present application; Figure 11 A lens imaging ray tracing diagram of the projection objective with a projection distance of 1200mm in the projection imaging method provided by the embodiment of the present application; Figure 12 An optical transfer function curve diagram of the projection objective with a projection distance of 1200mm in the projection imaging method provided by the embodiment of the present application; Figure 13 A distortion aberration diagram of the projection objective with a projection distance of 1200mm in the projection imaging method provided by the embodiment of the present application; Figure 14 A sagittal chromatic aberration diagram of the projection objective with a projection distance of 1200mm in the projection imaging method provided by the embodiment of the present application; Figure 15 A schematic diagram of the projection system provided by the embodiment of the present application; Figure 16 A schematic diagram of the projection system provided by the embodiment of the present application; Figure 15 A local enlarged view of the A position in the schematic diagram of the projection system provided by the embodiment of the present application; Figure 17 A schematic diagram of the projection system provided by the embodiment of the present application from another angle; Figure 18 A sectional view of the digital micromirror module of the projection system provided by the embodiment of the present application; Figure 19 An exploded view of the digital micromirror module of the projection system provided by the embodiment of the present application; Figure 20 A bottom view of the projection device provided by the embodiment of the present application; Figure 21 A schematic diagram of the mirror of the projection system provided by the embodiment of the present application; Figure 22 A schematic diagram of the shell of the projection system provided by the embodiment of the present application; Figure 23A schematic view of an adjusting screw of a projection system according to an embodiment of the present application; Figure 24 A sectional view at the position of a mirror of a projection system according to an embodiment of the present application; Figure 25 A sectional view at the position of a mirror of another projection system according to an embodiment of the present application; Figure 26 A schematic view of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 27 A schematic view of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 26 A sectional view in the direction of B-B; Figure 28 A perspective view of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 29 A schematic view of a guide slot cylinder of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 30 A schematic view of a guide slot cylinder of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 31 A schematic view of a guide slot cylinder of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 32 A schematic view of a cam cylinder of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 33 A schematic view of a cam cylinder of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 32 A sectional view in the direction of C-C; Figure 34 A perspective view of a cam cylinder of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 35 A schematic view at the position of a whole lens movement ring of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 36 A schematic view at the position of a whole lens movement ring of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 35 A sectional view in the direction of D-D; Figure 37 A schematic view of a movement orientation cylinder of a zoom projection lens of a projection system according to an embodiment of the present application; Figure 38 A movement curve diagram of a first curve sliding slot and a second curve sliding slot of a zoom projection lens of a projection system according to an embodiment of the present application.

[0080] Icon: 1-first meniscus lens; 2-biconcave lens; 3-second meniscus lens; 4-floating diaphragm; 5-biconvex lens; 6-third meniscus lens; 7-plano-convex lens; 8-TIR prism; 9-DMD galvanometer protection glass; 10-DMD galvanometer; 100-housing; 200-reflector; 300-light source; 1110-first side wall; 1111-first heat dissipation fin; 1120-second side wall; 1121-second heat dissipation fin; 1200-first fan; 1400-digital micro-mirror module; 1410-digital micro-mirror device; 1420-heat dissipation block; 1430-mounting seat; 1440-external circuit board; 1450-pressing block; 1460-arc-shaped pressing piece; 1470-locking screw; 1480-first spring; 1491-insulating piece; 1492-heat-conducting piece; 1500-second fan; 1600-third heat dissipation fin; 2110-first screw hole; 2500-adjusting screw; 2510-second screw hole; 2600-second spring; 2700-positioning column; 3100-guide groove cylinder; 3110-first linear limiting groove; 3120-second linear limiting groove; 3130-third curved sliding groove; 3140-third linear limiting groove; 3200-cam cylinder; 3210-first curved sliding groove; 3220-second curved sliding groove; 3230-first end; 3240-second end; 3250-mounting hole; 3300-vari-focal lens group; 3310-first limiting pin; 3400-compensation lens group; 3410-second limiting pin; 3510-first gear ring; 3520-first gear; 3530-first motor; 3610-motion orientation cylinder; 3611-arc-shaped sliding groove; 3612-third limiting pin; 3620-entire-mirror motion ring; 3621-fourth limiting pin; 3710-second gear ring; 3720-second gear; 3730-second motor. DETAILED DESCRIPTION

[0081] The technical solutions of the present application will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present application.

[0082] As shown in the figure, the projection imaging method provided by the embodiment of the present application comprises the following steps: Figures 1-2 S1. Obtain the projection distance between the zoom projection lens and the to-be-projected surface.

[0083]

[0084] ​In this embodiment, the projection distance can be acquired by using a light field camera, a vision solution (monocular and multi-camera vision solutions), or a radar ranging solution. After the projection distance is acquired, the projection distance information can be transmitted to the zoom projection lens.

[0085] S2. Obtain a target divergence angle value of the light emitted from the zoom projection lens according to the projection distance and the size of the preset projection image.

[0086] The preset projection image can be a square with dimensions of 290mm x 290mm. During surgery, the zoom projection lens is approximately 800mm-1200mm away from the patient. Knowing the projection distance and the specific dimensions of the projected image, the target divergence angle of the emitted light can be calculated through geometric deduction. In other words, the divergence angle of the emitted light from the zoom projection lens needs to be adjusted to the desired value in order to form the preset projection image on the projection surface at the specified projection distance.

[0087] S3. Adjust the divergence angle value of the output light of the zoom projection lens to be equal to the target divergence angle value.

[0088] like Figure 27 As shown, the divergence angle of the light emitted from the zoom projection lens can be changed by changing the position of the compensation lens group 3400 and the magnification lens group 3300 on the optical axis within the zoom projection lens. The zoom projection lens may include the compensation lens group 3400, the magnification lens group 3300, and a driving mechanism. The driving mechanism is connected to the compensation lens group 3400 and the magnification lens group 3300, respectively. After obtaining a target divergence angle value, the driving mechanism can drive the compensation lens group 3400 and the magnification lens group 3300 to move back and forth to the target position, thereby making the divergence angle value of the light emitted from the zoom projection lens equal to the target divergence angle value.

[0089] In the case that the projection distance between the size of the preset projection image and the distance to the projection surface is fixed, the target divergence angle value of the outgoing light of the zoom projection lens can be obtained through geometric calculation, and then the zoom projection lens is adjusted according to the target divergence angle value, so that the divergence angle value of the outgoing light of the zoom projection lens is equal to the target divergence angle value, and then the size of the projection image projected on the projection surface is the preset size, that is, the change of the projection distance between the zoom projection lens and the projection surface will cause the change of the divergence angle value of the outgoing light of the zoom projection lens, so that the size of the projection image projected on the projection surface is always unchanged. The preoperative image of the patient can be projected on the patient's body according to the fixed size, because the size of the projection image is unchanged, the length and width of the line drawing pattern on the image are always unchanged, so that the doctor can directly draw lines and perform surgery according to the information on the projection image. The above projection imaging method can assist the doctor to complete the surgery, and the doctor does not need to repeatedly compare the information on the screen and the patient's body, which can reduce the difficulty of the surgery and improve the success rate of the surgery.

[0090] As shown in Figure 2 The projection objective lens involved in the embodiment can include a digital micro-mirror module 1400, a DMD mirror protection glass 9 and a TIR prism 8. The light emitted by the DMD chip enters the zoom projection lens in sequence through the DMD protection glass and the TIR prism 8. The mirror array of the DMD mirror 10 is 912*1140, with a 7.6-micron pitch and a size of 9.855*6.681 mm. A part of 6.681*6.681 mm is selected, the mirror array of which is 912*912, and the projection is 290 mm*290 mm. The size of the object surface controlled by each mirror (pixel accuracy) is 290 / 912=0.317 mm, and there are 36 pixels in a 2 mm*2 mm space.

[0091] The focal length of the projection objective lens is 18.1-26.4 mm, the object-image ratio is 46.9, the object surface size is 290 mm*290 mm, the projection distance is 800 mm-1200 mm, the focusing mode is zooming+compensation, the image quality requirement is >0.35 at the maximum field of view of 93 lp / mm, the distortion is <5%, the objective lens form is 6pcs of lenses, and the tolerance level is f9.

[0092] In order to realize that the size of the projected image is always constant within a certain projection range, the following zoom projection lens is used in the embodiment, wherein the zoom projection lens comprises a compensation lens group 3400, a variable magnification lens group 3300 and a front group. In use, the distance between the current projection surface to be projected and the zoom projection lens is identified by an optical field camera, a visual scheme (monocular and multiocular visual scheme) or a radar ranging scheme, and the relative positions of the compensation lens group 3400 and the variable magnification lens group 3300 are adjusted by a driving mechanism to achieve the zoom effect.

[0093] Specifically, the front group comprises a first meniscus lens 1 located on the light exit side of the variable magnification lens group 3300, the first meniscus lens 1 comprises a light exit curve S1 protruding towards the light exit side, and a light entrance curve S2 recessed towards the light exit side. The variable magnification lens group 3300 comprises a second meniscus lens 3 and a biconcave lens 2 arranged in sequence along the light exit direction; the biconcave lens 2 comprises a light exit curve S3 recessed towards the light entrance side, and a light entrance curve S4 recessed towards the light exit side; the second meniscus lens 3 comprises a light exit curve S5 recessed towards the light entrance side, and a light entrance curve S6 protruding towards the light exit side. The compensation lens group 3400 comprises a plano-convex lens 7, a third meniscus lens 6 and a biconvex lens 5 arranged in sequence along the light exit direction; the biconvex lens 5 comprises a light exit curve S7 protruding towards the light exit side, and a light entrance curve S8 protruding towards the light entrance side; the third meniscus lens 6 comprises a light exit curve S9 recessed towards the light entrance side, and a light entrance curve S10 protruding towards the light entrance side; the plano-convex lens 7 comprises a light exit curve S11 protruding towards the light exit side, and a light entrance plane S12.

[0094] A floating diaphragm 4 can be arranged on the light exit side of the biconvex lens 5.

[0095] The focal length f1 of the first meniscus lens 1 ranges from 116mm to 118mm; the focal length f2 of the biconcave lens 2 ranges from -19mm to -17mm; the focal length f3 of the second meniscus lens 3 ranges from 57mm to 59mm; the focal length f4 of the biconvex lens 5 ranges from 20mm to 22mm; the focal length f5 of the third meniscus lens 6 ranges from -38mm to -36mm; and the focal length f6 of the plano-convex lens 7 ranges from 39mm to 41mm. The embodiment provides a set of implementable data, wherein f1 = 117.933 mm, f2 = -18.49 mm; f3 = 58.87 mm; f4 = 21.646 mm; f5 = -37.902 mm; and f6 = 40.089 mm.

[0096] The axial distance between the light-out curved surface S1 and the light-in curved surface S2 is greater than 4mm and less than 6mm; the axial distance between the light-in curved surface S2 and the light-out curved surface S3 is greater than 3mm and less than 5mm; the axial distance between the light-out curved surface S3 and the light-in curved surface S4 is greater than 1mm and less than 2mm; the axial distance between the light-in curved surface S4 and the light-out curved surface S5 is greater than 1.8mm and less than 3.8mm; the axial distance between the light-out curved surface S5 and the light-in curved surface S6 is greater than 2.5mm and less than 4.5mm; the axial distance between the light-out curved surface S7 and the light-in curved surface S8 is greater than 4mm and less than 6mm; the axial distance between the light-in curved surface S8 and the light-out curved surface S9 is greater than 0.5mm and less than 1.5mm; the axial distance between the light-out curved surface S9 and the light-in curved surface S10 is greater than 1mm and less than 2mm; the axial distance between the light-in curved surface S10 and the light-out curved surface S11 is greater than 0.25mm and less than 0.75mm; the axial distance between the light-out curved surface S11 and the light-in plane S12 is greater than 2.5mm and less than 4.5mm.

[0097] The light-out curved surface S1 is a spherical surface, and the radius of curvature is greater than 24mm and less than 26mm; the light-in curved surface S2 is a spherical surface, and the radius of curvature is greater than 35mm and less than 37mm; the light-out curved surface S3 is a spherical surface, and the radius of curvature is greater than -13mm and less than -11mm; the light-in curved surface S4 is a spherical surface, and the radius of curvature is greater than 76mm and less than 80mm; the light-out curved surface S5 is a spherical surface, and the radius of curvature is greater than -15mm and less than -13mm; the light-out curved surface S6 is a spherical surface, and the radius of curvature is greater than -12mm and less than -10mm; the light-out curved surface S7 is a spherical surface, and the radius of curvature is greater than 34mm and less than 36mm; the light-in curved surface S8 is a spherical surface, and the radius of curvature is greater than -20mm and less than -18mm; the light-out curved surface S9 is a spherical surface, and the radius of curvature is greater than -18mm and less than -16mm; the light-in curved surface S10 is a spherical surface, and the radius of curvature is greater than -40mm and less than -38mm; the light-out curved surface S11 is a spherical surface, and the radius of curvature is greater than 22mm and less than 24mm.

[0098] In this embodiment, a set of specific scheme parameters that can be implemented by the zoom projection lens are provided, and the specific parameters are shown in Table 1.

[0099] Table 1

[0100]

[0101] By adjusting the projection distance, optical tests are performed on the above-described zoom projection lens, where the projection distance is selected as 800mm, 1000mm and 1200mm, and the test results are shown in Table 2. Figures 3-14As shown in the figure, the MTFs on the 93 line pairs are all greater than 0.3, meeting the design and tolerance requirements.

[0102] The projection system provided by the embodiment of the present application applies the projection imaging method described above. Since the projection system provided by the embodiment of the present application refers to the projection imaging method described above, the projection system provided by the embodiment of the present application also has the advantages of the projection imaging method.

[0103] As shown in the figure, Figure 15 The projection system can include a distance detection mechanism, a zoom projection lens, a zoom driving mechanism, and a controller, the controller is electrically connected with the distance detection mechanism and the zoom driving mechanism respectively; the distance detection mechanism is used to obtain the projection distance between the zoom projection lens and the surface to be projected; the controller is used to obtain the target divergence angle value of the outgoing light of the zoom projection lens according to the projection distance and the size of the preset projection image; the zoom driving mechanism is connected with the zoom projection lens, and the zoom driving mechanism is used to adjust the divergence angle value of the outgoing light of the zoom projection lens to equal the target divergence angle value.

[0104] The distance detection mechanism can be used to obtain the projection distance between the zoom projection lens and the surface to be projected. The target divergence angle value calculated by the controller is transmitted to the zoom driving mechanism, and the zoom driving mechanism can change the divergence angle of the outgoing light of the zoom projection lens by changing the positions of the compensation lens group 3400 and the variable magnification lens group 3300 on the optical axis. Specifically, the zoom driving mechanism is connected with the compensation lens group 3400 and the variable magnification lens group 3300 respectively, and after obtaining the target divergence angle value, the zoom driving mechanism can drive the compensation lens group 3400 and the variable magnification lens group 3300 to move forward and backward to the target position, so that the divergence angle value of the outgoing light of the zoom projection lens is equal to the target divergence angle value. The zoom driving mechanism can be a linear motor.

[0105] As shown in the figure, Figure 15 The projection system further includes a housing 100, a mirror 200, and a light source 300, the light source 300 and the zoom projection lens are arranged side by side along the left-right direction, the mirror 200 is used to reflect the light emitted by the light source 300 to the TIR prism 8 in the same column as the zoom projection lens, and the TIR prism 8 is located between the digital micromirror module 1400 and the zoom projection lens.

[0106] The projection device includes a housing 100 and a first fan 1200, the material of the housing 100 can be oxidized black aluminum alloy, or other metals, non-metallic materials such as copper, stainless steel, and plastic; considering the influence of optics, the color of the housing 100 can be black, such as paint, oxidation, and other ways to realize the conversion of the color of the material; the surface of the housing 100 can be sandblasted, which can absorb a lot of stray light.

[0107] As Figure 16 shown, the shell 100 includes a first side wall 1110 and a second side wall 1120 arranged on the circumferential side, and one end of the first side wall 1110 is connected with one end of the second side wall 1120. In order to improve the heat dissipation efficiency, the outer side of the first side wall 1110 is provided with a plurality of first heat dissipation fins 1111 extending along the length direction thereof, and the outer side of the second side wall 1120 is provided with a plurality of second heat dissipation fins 1121 extending along the length direction thereof, and the first heat dissipation fins 1111 and the second heat dissipation fins 1121 can increase the contact area with air. The first heat dissipation fins 1111 and the second heat dissipation fins 1121 are the same in number and one-to-one corresponding, one end of the first heat dissipation fin 1111 is connected with one end of the corresponding second heat dissipation fin 1121, and a heat dissipation flow channel is formed between the upper and lower adjacent first heat dissipation fin 1111 and second heat dissipation fin 1121.

[0108] The first fan 1200 can be a silent fan, which reduces the noise when working, and the first fan 1200 is installed on the shell 100, and the first fan 1200 is located at one end of the second heat dissipation fin 1121 away from the first heat dissipation fin 1111, and the first fan 1200 blows air towards the second heat dissipation fin 1121.

[0109] On the one hand, the arrangement of the first heat dissipation fin 1111 and the second heat dissipation fin 1121 can increase the contact area of the shell 100 with the outside world and improve the heat dissipation capacity; on the other hand, the adjacent two second heat dissipation fins 1121 can form a heat dissipation flow channel extending along the length direction of the second side wall 1120, and the air blown by the first fan 1200 located at one end of the second heat dissipation fin 1121 can advance along the heat dissipation flow channel to the other end of the second heat dissipation fin 1121, so as to fully dissipate heat to the second side wall 1120, and then dissipate heat to the electrical elements installed on the second side wall 1120; and because the first heat dissipation fin 1111 and the second heat dissipation fin 1121 are one-to-one corresponding and connected with each other, the heat of the first heat dissipation fin 1111 can also be transmitted to the second heat dissipation fin 1121, so as to realize further heat dissipation of the first heat dissipation fin 1111. In the present scheme, the first heat dissipation fin 1111, the second heat dissipation fin 1121 and the first fan 1200 are used to dissipate heat to the two side surfaces of the corner, the heat dissipation coverage area is large, and the structure is simple.

[0110] The first side wall 1110 is provided with a first mounting groove recessed inwardly, the first heat dissipation fin 1111 is located in the first mounting groove, and the width of the first heat dissipation fin 1111 is less than or equal to the depth of the first mounting groove; the second side wall 1120 is provided with a second mounting groove recessed inwardly, the second heat dissipation fin 1121 is located in the second mounting groove, and the width of the second heat dissipation fin 1121 is less than or equal to the depth of the second mounting groove.

[0111] The first heat dissipation fin 1111 is arranged in the first mounting groove recessed inwardly on the first side wall 1110, and the width of the first heat dissipation fin 1111 is limited; the second heat dissipation fin 1121 is arranged in the second mounting groove recessed inwardly on the second side wall 1120, and the width of the second heat dissipation fin 1121 is limited, so that the circumferential outer wall of the shell 100 is more flat and uniform, and the first heat dissipation fin 1111 and the second heat dissipation fin 1121 are prevented from being outwardly convex and scratching the user.

[0112] The first heat dissipation fin 1111 can also be formed in a slotted manner, that is, a plurality of groove bodies extending along the length direction are formed on the outer surface of the first side wall 1110, and the structure between the upper and lower adjacent groove bodies can form the first heat dissipation fin 1111, so that the top surface of the first heat dissipation fin 1111 is flush with the outer surface of the first side wall 1110. The forming manner of the second heat dissipation fin 1121 can be the same as that of the first heat dissipation fin 1111.

[0113] The projection of each second heat dissipation fin 1121 on the air outlet of the first fan 1200 falls in the air outlet. In order to enable each heat dissipation fin to be affected by the air blown by the first fan 1200, the air outlet of the first fan 1200 needs to be arranged to be large enough, thereby improving the heat dissipation efficiency of the second heat dissipation fin 1121.

[0114] The first heat dissipation fin 1111 and the second heat dissipation fin 1121 are integrally formed, the heat conduction capacity of the first heat dissipation fin 1111 and the second heat dissipation fin 1121 is the same, there is no obstruction in the conduction of heat, and the heat on the first heat dissipation fin 1111 can be more smoothly transmitted to the second heat dissipation fin 1121.

[0115] The inner surface of the first side wall 1110 and the inner surface of the second side wall 1120 are both provided with light sources 300. Specifically, in the embodiment, blue LED light sources 300 are arranged on the inner surface of the first side wall 1110, and red LED light sources 300 and green LED light sources 300 can be arranged on the inner surface of the second side wall 1120. When the light sources 300 emit light, the heat generated by the light sources 300 is transmitted to the first heat dissipation fin 1111 and the second heat dissipation fin 1121 through the shell 100.

[0116] The bottom surface of the light source 300 on the first side wall 1110 is close to the inner surface of the first side wall 1110, and the bottom surface of the light source 300 on the second side wall 1120 is close to the inner surface of the second side wall 1120, so that heat transfer between the light source 300 and the inner wall of the shell 100 is realized. Further, the bottom surface of the light source 300 on the first side wall 1110 and the inner surface of the first side wall 1110 are filled with a heat-conducting agent, and the bottom surface of the light source 300 on the second side wall 1120 and the inner surface of the second side wall 1120 are also filled with a heat-conducting agent. Specifically, the heat-conducting agent is a heat-conducting silicone material. In the heat dissipation process, even if two very smooth surfaces are in contact, there will be gaps between them. The air in these gaps is a poor conductor of heat, which will hinder the conduction of heat to the heat sink. The heat-conducting silicone can fill these gaps, making the conduction of heat more smooth and rapid.

[0117] Further, the projection device further comprises a refrigeration mechanism, which belongs to the prior art. The refrigeration mechanism comprises a refrigeration sheet connected to a power supply. After being powered on, one side of the refrigeration sheet can be refrigerated, and the other side can be heat-dissipated. The refrigeration sheet comprises a low-temperature surface and a high-temperature surface facing away from each other. The refrigeration sheet is located between the bottom surface of the light source 300 and the inner surface of the second side wall 1120, and the low-temperature surface faces the light source 300, and the high-temperature surface faces the inner surface of the second side wall 1120. The light source 300 and the refrigeration sheet are filled with a heat-conducting agent, and the refrigeration sheet and the inner surface of the second side wall 1120 are also filled with a heat-conducting agent. The heat generated by the light source 300 can be more quickly transferred to the shell 100 through the refrigeration sheet and the heat-conducting agent, accelerating the cooling of the light source 300.

[0118] The first heat sink 1111 is located on the front side of the shell 100, and the second heat sink 1121 is located on the left side or the right side of the shell 100. The first fan 1200 is installed on the rear side of the shell 100, and the first fan 1200 is arranged on the rear side of the shell 100, so that the hiding effect is better.

[0119] The materials of the first heat sink 1111 and the second heat sink 1121 are aluminum or copper. The material aluminum has a lighter mass, and the material copper has a higher heat-conducting efficiency.

[0120] As Figures 17-19As shown, the projection device further comprises a digital micro-mirror module 1400 and a second fan 1500, which can be located on the back of the housing 100. The digital micro-mirror module 1400 comprises a digital micro-mirror device 1410 (DMD) and a heat sink 1420, the back of the digital micro-mirror device 1410 has a heat dissipation surface, one end of the heat sink 1420 is connected to the heat dissipation surface, the heat sink 1420 can quickly conduct the heat generated by the digital micro-mirror device 1410 to the outside, and the second fan 1500 is used to blow air towards the heat sink 1420, thereby cooling the heat sink 1420.

[0121] Specifically, the digital micro-mirror module 1400 further comprises a mounting seat 1430, an external circuit board 1440, a pressing block 1450, an arc-shaped pressing sheet 1460 and locking screws 1470 arranged in sequence. The mounting seat 1430 is in the shape of a rectangular frame, the front surface of the digital micro-mirror device 1410 is mounted on the mounting seat 1430, the external circuit board 1440 is located on the side of the digital micro-mirror device 1410 away from the mounting seat 1430, the external circuit board 1440 is provided with a first avoiding hole aligned with the heat dissipation surface and used for avoiding the heat dissipation surface, and the two sides of the first avoiding hole are provided with second contact positions used for connecting the first contact positions of the digital micro-mirror device 1410. The external circuit board 1440 is pressed on the digital micro-mirror device 1410, the first contact positions are connected to the second contact positions, the circuit connection of the two is realized, and real-time control is realized. The number of the locking screws 1470 is two, the two locking screws 1470 are located on the two sides of the digital micro-mirror device 1410, the mounting seat 1430 is provided with two screw holes, and the digital micro-mirror device 1410, the external circuit board 1440 and the pressing block 1450 are all provided with two through holes in correspondence. The locking screws 1470 pass through the pressing block 1450, the external circuit board 1440 and the screw holes on the mounting seat 1430 in sequence and are connected. A second spring 2600 is arranged between the nut of the locking screw 1470 and the pressing block 1450, the pressing block 1450 is used for pressing the external circuit board 1440 above the digital micro-mirror device 1410, after the locking screw 1470 is tightened, the second spring 2600 is compressed, and the rebound force of the second spring 2600 compresses the contact points on the external circuit board 1440 on the contact positions of the digital micro-mirror device 1410.

[0122] The second avoiding hole is arranged on the pressing block 1450 and is aligned with the first avoiding hole; one end of the heat dissipation block 1420 is in abutment with the heat dissipation surface after passing through the first avoiding hole and the second avoiding hole; the two ends of the pressing plate are respectively connected with the two locking screws 1470, and the pressing plate is used for abutting on the heat dissipation block 1420 so that the heat dissipation block 1420 is pressed on the heat dissipation surface. The heat dissipation block 1420 is clamped between the pressing plate and the heat dissipation surface, and the heat generated by the heat dissipation surface is transmitted to the outside through the heat dissipation block 1420.

[0123] An insulating sheet 1491 can be arranged between the pressing block 1450 and the external circuit board 1440, and a heat conducting sheet 1492 can be arranged between the heat dissipation block 1420 and the heat dissipation surface, so as to improve the heat conduction efficiency.

[0124] The digital micro-mirror device 1410 is prevented from being damaged, the limiting boss is arranged on the mounting seat 1430 and is used for supporting the external circuit board 1440 to avoid that the digital micro-mirror device 1410 is excessively pressed by the external circuit board 1440. Meanwhile, the limiting boss has another effect of preventing the contacts on the external circuit board from being excessively pressed and being all attached on the contact positions on the digital micro-mirror device 1410, so that the contacts are simultaneously arranged on two contact points and the digital micro-mirror device 1410 is locally short-circuited.

[0125] As shown in Figure 20 The projection device further comprises a TIR prism 8 located in front of the optical action surface of the digital micro-mirror module 1400; the TIR prism 8 is located in the shell 100, and the third heat dissipation sheet 1600 is arranged on the position corresponding to the TIR prism 8 on the outer wall of the shell 100, the length direction of the third heat dissipation sheet 1600 is parallel to the air outlet direction of the second fan 1500, and the air outlet area of the second fan 1500 covers the third heat dissipation sheet 1600. The third heat dissipation sheet 1600 is located on the bottom surface of the shell 100, and the length direction of the third heat dissipation sheet 1600 is the left-right direction of the shell 100, and the second fan 1500 can simultaneously dissipate heat for the third heat dissipation sheet 1600 and the digital micro-mirror module 1400.

[0126] As shown in Figures 21-23As shown, a plurality of first screw holes 2110 are provided on the side wall of the shell 100, which pass through the inside and outside of the shell 100, and an adjusting screw 2500 is threadedly connected to the inner surface of the first screw hole 2110, and a second screw hole 2510 is provided in the adjusting screw 2500, which extends along its length direction and passes through its front and rear end surfaces; a positioning column 2700 corresponding to the first screw hole 2110 is provided on the back of the reflector 200; one end of the positioning column 2700 is connected to the reflector 200, and the other end is threadedly connected to the second screw hole 2510; and a first spring 1480 is provided between the shell 100 and the reflector 200, one end of the first spring 1480 is connected to the shell 100, and the other end is connected to the reflector 200, and the first spring 1480 is used to pull the reflector 200 toward the shell 100 or push it toward the direction away from the shell 100.

[0127] The adjustment principle of the reflector 200 of the projector in this embodiment is as follows: rotating the adjusting screw 2500 can make the positioning column 2700 move back and forth relative to the adjusting screw 2500. By selectively adjusting the adjusting screws 2500 at different positions, the inclination of the reflector 200 can be changed. Therefore, there is no need to completely disassemble the shell 100 to adjust the inclination of the reflector 200, and the adjustment is simple; and under the action of the first spring 1480, the reflector 200 can always be kept in a taut state, which can effectively eliminate the thread gap and make the debugging of the reflector 200 components more accurate and reliable.

[0128] like Figure 24 As shown, in one possible implementation, the first spring 1480 is located within the shape formed by the plurality of positioning posts 2700. The first spring 1480 can be used to tighten the threads of the plurality of positioning posts 2700. Specifically, a first pin is provided on the housing 100, and a second pin is provided on the reflector 200. One end of the first spring 1480 is hooked on the first pin, and the other end is hooked on the second pin. When the first spring 1480 is in a tightened state, the reflector 200 is pulled toward the housing 100, and the threads of the adjusting screw 2500 and the first screw hole 2110, as well as the threads of the positioning post 2700 and the second screw hole 2510, are all in close contact.

[0129] Furthermore, to prevent the first and second pins from interfering with the reflector 200, the first pin is located inside the housing 100, and a first channel communicating with the interior of the housing 100 is provided on the inner wall of the housing 100. The second pin is located inside the reflector 200, and a second channel communicating with the interior of the reflector 200 is provided on the back of the reflector 200. One end of a first spring 1480 extends into the first channel and connects to the first pin, while the other end of the first spring 1480 extends into the second channel and connects to the second pin.

[0130] like Figure 25 As shown, in another possible implementation, the first spring 1480 is sleeved on the outside of the positioning post 2700, with one end of the first spring 1480 abutting the inner wall of the housing 100 and the other end abutting the back surface of the reflector 200. A first spring 1480 is sleeved on the circumferential outer side of each positioning post 2700. The first spring 1480 is in a compressed state and is used to push the reflector 200 away from the inner wall of the housing 100, thereby causing the threads of the adjusting screw 2500 and the first screw hole 2110, as well as the threads of the positioning post 2700 and the second screw hole 2510 to fit tightly.

[0131] The reflector 200 includes a frame and a lens. The lens can be fixed to the frame using optical glue. One end of the positioning post 2700 is screwed into the frame, and thread glue is used to secure the reflector 200 and the positioning post 2700 relative to each other. The outer surface of the frame is black to prevent it from affecting the light emitted by the light source 300. Furthermore, the outer surface of the frame has a frosted texture to absorb some stray light.

[0132] The number of the first screw holes 2110 is greater than or equal to two. In this embodiment, the number of the first screw holes 2110 is three. The three first screw holes 2110 are located at the vertices of a triangle, and the adjustment screws 2500 are fine-tuned to fine-tune the optical path.

[0133] The first screw hole 2110 has a first internal thread on its inner wall, and the second screw hole 2510 has a second internal thread on its inner wall. The first and second internal threads can have the same or opposite spiral directions. If the first and second internal threads have the same spiral direction, the adjustment distance is the difference between their pitches. If the first and second internal threads have opposite spiral directions, the adjustment distance is the sum of their pitches.

[0134] The first internal thread and the second internal thread have the same rotation direction, and the pitch of the first internal thread is greater than the pitch of the second internal thread. By virtue of the pitch difference between the first internal thread and the second internal thread, the adjustment accuracy can be improved, for example, the pitch of the first internal thread can be 0.75 mm, and the pitch of the second internal thread can be 0.5 mm. When the adjusting screw 2500 is rotated, the adjusting screw 2500 moves inward, and the positioning column 2700 moves outward, and the adjustment accuracy is 0.75-0.5=0.25 mm.

[0135] As shown in Figure 26 The zoom projection lens comprises a guide groove barrel 3100, a cam barrel 3200, a variable magnification lens group 3300 and a compensation lens group 3400. The variable magnification lens group 3300 comprises a first lens holder and a first limiting pin 3310 connected to the outer wall of the first lens holder. The first lens holder is arranged with lens elements, and the outer wall of the first lens holder is provided with a threaded hole, and one end of the first limiting pin 3310 can be threadedly connected with the threaded hole on the outer wall of the first lens holder. The compensation lens group 3400 comprises a second lens holder and a second limiting pin 3410 connected to the outer wall of the second lens holder. The second lens holder is arranged with lens elements, and the outer wall of the second lens holder is provided with a threaded hole, and one end of the second limiting pin 3410 can be threadedly connected with the threaded hole on the outer wall of the second lens holder. The first lens holder and the second lens holder are both located in the guide groove barrel 3100, and the first lens holder and the second lens holder can move along the axial direction of the guide groove barrel 3100.

[0136] The cam barrel 3200 is sleeved on the outside of the guide groove barrel 3100, the cam barrel 3200 is coaxially arranged with the guide groove barrel 3100, and the cam barrel 3200 can rotate relative to the guide groove barrel 3100; the guide groove barrel 3100 is provided with a first straight limiting groove 3110 and a second straight limiting groove 3120 extending along the axial direction thereof, and the first straight limiting groove 3110 and the second straight limiting groove 3120 both communicate the inner and outer walls of the guide groove barrel 3100. The first limiting pin 3310 is located in the first straight limiting groove 3110, and the width of the first straight limiting groove 3110 is consistent with the outer diameter of the first limiting pin 3310, so that the first limiting pin 3310 is only allowed to move along the length direction of the first straight limiting groove 3110. The second limiting pin 3410 is located in the second straight limiting groove 3120, and the width of the second straight limiting groove 3120 is consistent with the outer diameter of the second limiting pin 3410, so that the second limiting pin 3410 is only allowed to move along the length direction of the second straight limiting groove 3120.

[0137] The cam cylinder 3200 is provided with a first curved sliding groove 3210 and a second curved sliding groove 3220, and the first curved sliding groove 3210 and the second curved sliding groove 3220 are helically extended along the axial direction of the cam cylinder 3200. The first curved sliding groove 3210 and the second curved sliding groove 3220 can be located on the inner wall of the cam cylinder 3200. The first limiting pin 3310 is inserted into the first curved sliding groove 3210 after penetrating the first linear limiting groove 3110, and the second limiting pin 3410 is inserted into the second curved sliding groove 3220 after penetrating the second linear limiting groove 3120. When the cam cylinder 3200 rotates relative to the guide groove cylinder 3100, the first curved sliding groove 3210 and the second curved sliding groove 3220 can drive the variable magnification lens group 3300 and the compensation lens group 3400 to move axially, respectively. The specific principle is as follows:

[0138] As shown in Figures 27-34 , in use, the guide groove cylinder 3100 can be fixed, and the cam cylinder 3200 is rotated relative to the guide groove cylinder 3100. Since the first linear limiting groove 3110 restricts the first limiting pin 3310 from rotating and only allows it to move axially, the side wall of the first curved sliding groove 3210 on the cam cylinder 3200 can push the first limiting pin 3310 to move axially during rotation, thereby changing the axial position of the variable magnification lens group 3300. Similarly, since the second linear limiting groove 3120 restricts the second limiting pin 3410 from rotating and only allows it to move axially, the side wall of the second curved sliding groove 3220 on the cam cylinder 3200 can push the second limiting pin 3410 to move axially during rotation, thereby changing the axial position of the compensation lens group 3400. By adopting the above scheme, the linkage effect of the variable magnification lens group 3300 and the compensation lens group 3400 can be achieved. When adjusting the zoom, two driving forces are not needed to be controlled separately, and only the rotation of the cam cylinder 3200 needs to be controlled to achieve the effect of simultaneously controlling the variable magnification group and the compensation group. On the one hand, the reliability of the movement and adjustment of the zoom group during zooming is increased, and on the other hand, the number of parts is reduced, and the risk of errors is reduced.

[0139] As shown in Figure 34 , the cam cylinder 3200 includes a first end 3230 and a second end 3240, the first curved sliding groove 3210 and the second curved sliding groove 3220 are sequentially arranged along the direction from the first end 3230 to the second end 3240, and the end of the first curved sliding groove 3210 close to the first end 3230 is in communication with the end face of the first end 3230.

[0140] The variable magnification lens group 3300 is located in the middle of the guide groove cylinder 3100. The first limiting pin 3310 continuously passes through the cam cylinder 3200 and the guide groove cylinder 3100, and is inconvenient to align the first lens holder in the guide groove cylinder 3100. Therefore, during assembly, the first lens holder is first placed into the guide groove cylinder 3100, and then the first limiting pin 3310 is connected with the first lens holder by passing through the first straight limiting slot 3110. Then, the cam cylinder 3200 is sleeved on the guide groove cylinder 3100, and the first end 3230 abuts against the first limiting pin 3310. The cam cylinder 3200 is rotated, so that the opening of the first curved sliding groove 3210 in communication with the first end 3230 is aligned with the first limiting pin 3310. The cam cylinder 3200 is continuously rotated, so that the first limiting pin 3310 enters the first curved sliding groove 3210, and the cam cylinder 3200 and the guide groove cylinder 3100 can be connected in place.

[0141] The cam cylinder 3200 is provided with a mounting hole 3250 in communication with the inner and outer surfaces thereof. The mounting hole 3250 corresponds to the second limiting pin 3410, and the mounting hole 3250 is located at the end point of the second curved sliding groove 3220.

[0142] As shown in Figure 32 Because the second lens holder is close to the opening end of the guide groove cylinder 3100, it is relatively easy to continuously pass through the cam cylinder 3200 and the guide groove cylinder 3100 to tighten the second limiting pin 3410. Therefore, in the embodiment, the mounting hole 3250 is formed on the cam cylinder 3200 to mount the second limiting pin 3410. The position of the mounting hole 3250 is at the end point of the second curved sliding groove 3220. After the mounting hole 3250, the second straight limiting slot 3120 and the screw hole on the second lens holder are aligned, the second limiting pin 3410 is connected with the second lens holder. The second limiting pin 3410 is inserted into the inner wall of the mounting hole 3250, and the top end of the second limiting pin 3410 is lower than the bottom surface of the second curved sliding groove 3220, so that the second limiting pin 3410 can move along the second curved sliding groove 3220.

[0143] The zoom projection lens comprises a first driving mechanism mounted on the guide groove cylinder 3100, and the first driving mechanism is used to drive the cam cylinder 3200 to rotate relative to the guide groove cylinder 3100. Rotating the cam cylinder 3200 can make the first lens holder and the second lens holder move in the axial direction.

[0144] Specifically, the cam barrel 3200 is provided with a first gear ring 3510, the first driving mechanism includes a first motor 3530 and a first gear 3520 connected with the output shaft of the first motor 3530, and the first gear 3520 is engaged with the first gear ring 3510. The power of the first gear 3520 can be transmitted to the first gear ring 3510. In the actual product, if the radial distance between the first gear ring 3510 and the first gear 3520 is not enough, a gear set structure can be engaged between the two, so as to realize the power transmission of the first gear ring 3510 and the first gear 3520.

[0145] Wherein, the extension path parameters of the first curve sliding groove 3210 and the second curve sliding groove 3220 are the key parameters of zooming, and the rotation distance of the cam barrel 3200 has a corresponding relationship with the moving distance of the zoom lens group 3300 and the compensation lens group 3400 respectively. According to the corresponding relationship requirement between the zoom lens group 3300 and the compensation lens group 3400, the following functions are obtained:

[0146] As shown in Figure 38 The function corresponding to the first curve sliding groove 3210 is:

[0147] F(x)=2.138*x^4+2.469*x^3+7.9*x^2-33.72*x+0.01938

[0148] The function corresponding to the second curve sliding groove 3220 is:

[0149] F(x)=0.001146*x^3+0.05437*x^2+1.3487*x-0.02292

[0150] x is the rotation distance of the cam barrel 3200, and F(x) is the moving distance of the zoom group.

[0151] The function curve is attached to the cam barrel 3200, and the function curve is the motion curve of the first limit pin 3310 and the second limit pin 3410. The starting position of the compensation group curve is the position of the first lens holder when it is at the leftmost position, and the position of the first limit pin 3310 (the center point of the pin) on it. The starting position of the zoom group curve is the position of the second lens holder when it is at the rightmost position, and the position of the second limit pin 3410 (the center point of the pin) on it. The two positions have been determined by the structure. According to the two starting positions and the curve equation and curve relationship, the positions of the two curves on the cam barrel 3200 can be determined.

[0152] The zoom projection lens further includes a second driving mechanism, the second driving mechanism is connected with the guide groove barrel 3100, and the second driving mechanism is used for driving the guide groove barrel 3100 to move along the axial direction, so as to realize the focusing of the objective lens.

[0153] The guide groove cylinder 3100 is provided with a third curved sliding groove 3130 and a third linear limiting groove 3140 which are helically curved along the axial direction thereof; the second driving mechanism comprises a motion orientation cylinder 3610 and a whole mirror motion ring 3620, the motion orientation cylinder 3610 is sleeved on the outside of the guide groove cylinder 3100, the motion orientation cylinder 3610 is provided with an arc-shaped sliding groove 3611 which communicates the inner and outer walls thereof, the arc-shaped sliding groove 3611 extends along the circumferential direction of the motion orientation cylinder 3610; the inner wall of the motion orientation cylinder 3610 is provided with a third limiting pin 3612 which extends inwardly and is located in the third linear limiting groove 3140; the whole mirror motion ring 3620 is sleeved on the outside of the motion orientation cylinder 3610, the inner wall of the whole mirror motion ring 3620 is provided with a fourth limiting pin 3621 which extends inwardly and is located in the third curved sliding groove 3130 after penetrating through the arc-shaped sliding groove 3611.

[0154] As shown in Figure 28 , Figures 35-37 , the guide groove cylinder 3100 is provided with a third curved sliding groove 3130; the other side of the guide groove cylinder 3100 is provided with a third linear limiting groove 3140; the motion orientation cylinder 3610 comprises an arc-shaped sliding groove 3611 which can be semicircular; the other side of the motion orientation cylinder 3610 comprises a pin hole in which a third limiting pin 3612 is connected; the whole mirror motion ring 3620 comprises a threaded hole; the fourth limiting pin 3621 comprises a threaded end which is adapted to the threaded hole of the whole mirror motion ring 3620; the optical axis of the fourth limiting pin 3621 is inserted into the arc-shaped sliding groove 3611 of the motion orientation cylinder 3610; the optical axis of the fourth limiting pin 3621 is inserted into the third curved sliding groove 3130 of the guide groove cylinder 3100; the third limiting pin 3612 is inserted into the third linear limiting groove 3140 of the guide groove cylinder 3100; when the whole mirror motion ring 3620 makes a circular motion relative to the guide groove cylinder 3100, the guide groove cylinder 3100 can only make a linear motion, thereby completing the focusing work.

[0155] In the embodiment, the second driving mechanism further comprises a second gear ring 3710 arranged on the outer wall of the whole-mirror movement ring 3620, and a second motor 3730, an output end of the second motor 3730 being connected with a second gear 3720, the second gear ring 3710 being engaged with the second gear 3720, and the power of the second gear 3720 being able to be transmitted to the second gear ring 3710. In the actual product, if the radial distance between the second gear ring 3710 and the second gear 3720 is not enough, a gear set structure can be engaged and connected between the second gear ring 3710 and the second gear 3720, so as to realize the power transmission of the second gear 3720 and the second gear ring 3710. The second motor 3730 can drive the second gear 3720 to rotate after being started, so as to drive the second gear ring 3710 and the whole-mirror movement ring 3620 to rotate.

[0156] In other embodiments, the second driving mechanism can comprise a linear driving module, a linear driving end of the linear driving module being connected with the guide groove cylinder 3100, and directly driving the guide groove cylinder 3100 to move along the axial direction as a whole.

[0157] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A projection system, characterized in that: Apply projection imaging methods; The projection system comprises: a housing (100) and a first fan (1200); the housing (100) comprises a first side wall (1110) and a second side wall (1120) arranged on a circumferential side surface, and one end of the first side wall (1110) is connected to one end of the second side wall (1120); The outer side of the first side wall (1110) is provided with a plurality of first heat sinks (1111) extending along its length direction, and the outer side of the second side wall (1120) is provided with a plurality of second heat sinks (1121) extending along its length direction; The first heat sinks (1111) and the second heat sinks (1121) are the same in number and correspond one to one, and one end of the first heat sink (1111) is connected to one end of the corresponding second heat sink (1121); The first fan (1200) is mounted on the housing (100), and the first fan (1200) is located at an end of the second heat sink (1121) away from the first heat sink (1111), and the first fan (1200) is used to blow air toward the second heat sink (1121); The projection imaging method comprises the following steps: S1. Get the projection distance between the zoom projection lens and the projection surface; S2 obtains the target divergence angle value of the light emitted by the zoom projection lens according to the projection distance and the preset size of the projected image; S3. Adjust the divergence angle of the light emitted by the zoom projection lens to be equal to the target divergence angle value; The projection system further comprises a digital micromirror module (1400) and a second fan (1500), wherein the digital micromirror module (1400) is mounted on the back of the housing (100); The digital micromirror module (1400) comprises a digital micromirror device (1410) and a heat dissipation block (1420); the back of the digital micromirror device (1410) has a heat dissipation surface, and one end of the heat dissipation block (1420) is connected to the heat dissipation surface; The second fan (1500) is used to blow air toward the heat dissipation block (1420); The projection system further comprises a TIR prism (8) located in front of the optical action surface of the digital micromirror module (1400); The TIR prism (8) is located in the housing (100), and a third heat sink (1600) is provided at a position on the outer wall of the housing (100) corresponding to the TIR prism (8), the length direction of the third heat sink (1600) is parallel to the air outlet direction of the second fan (1500), and the air outlet area of ​​the second fan (1500) covers the third heat sink (1600).

2. The projection system according to claim 1, wherein: Light sources (300) are mounted on the inner surface of the first side wall (1110) and the inner surface of the second side wall (1120).

3. The projection system according to claim 2, wherein: The bottom surface of the light source (300) on the first side wall (1110) is in close contact with the inner surface of the first side wall (1110); The bottom surface of the light source (300) on the second side wall (1120) is in close contact with the inner surface of the second side wall (1120).

4. The projection system according to claim 3, wherein: A thermal conductive agent is filled between the bottom surface of the light source (300) on the first side wall (1110) and the inner surface of the first side wall (1110), and between the bottom surface of the light source (300) on the second side wall (1120) and the inner surface of the second side wall (1120).

5. The projection system according to claim 1, wherein: A reflector (200) is provided between the light source (300) and the digital micromirror module (1400) in the housing (100); a plurality of first screw holes (2110) penetrating the inside and outside of the housing (100) are provided on the side wall of the housing (100); an adjusting screw (2500) is connected to the inner thread of the first screw hole (2110); and a second screw hole (2510) is provided in the adjusting screw (2500) extending along its length and penetrating its front and rear end surfaces; The back of the reflector (200) is provided with a positioning column (2700) corresponding one-to-one to the first screw hole (2110); one end of the positioning column (2700) is connected to the reflector (200), and the other end is threadedly connected to the second screw hole (2510); A first spring (1480) is provided between the housing (100) and the reflector (200), one end of the first spring (1480) being connected to the housing (100) and the other end being connected to the reflector (200), and the first spring (1480) being used to pull the reflector (200) toward the housing (100) or to push it toward the housing (100).

6. The projection system according to claim 5, wherein: A first internal thread is provided on the inner wall of the first screw hole (2110), and a second internal thread is provided on the inner wall of the second screw hole (2510), and the spiral directions of the first internal thread and the second internal thread are the same or opposite.

7. The projection system according to claim 6, wherein: The first internal thread and the second internal thread have the same rotation direction, and the pitch of the first internal thread is greater than the pitch of the second internal thread.

8. The projection system according to claim 1, wherein: The projection system comprises a zoom projection lens, which comprises a guide groove cylinder (3100), a cam cylinder (3200), a magnification lens group (3300) and a compensation lens group (3400); the magnification lens group (3300) comprises a first lens frame and a first limiting pin (3310) connected to the outer wall of the first lens frame; the compensation lens group (3400) comprises a second lens frame and a second limiting pin (3410) connected to the outer wall of the second lens frame; the first lens frame and the second lens frame are both located within the guide groove cylinder (3100); the cam cylinder (3200) is sleeved on the outside of the guide groove cylinder (3100); the cam cylinder (3200) and the guide groove cylinder (3100) are coaxially arranged, and the cam cylinder (3200) is rotatable relative to the guide groove cylinder (3100); The guide groove cylinder (3100) is provided with a first linear limiting groove (3110) and a second linear limiting groove (3120) extending along its axial direction, and the first linear limiting groove (3110) and the second linear limiting groove (3120) are both connected to the inner and outer walls of the guide groove cylinder (3100); the cam cylinder (3200) is provided with a first curved sliding groove (3210) and a second curved sliding groove (3220), and the first curved sliding groove (3210) and the second curved sliding groove (3220) are both extended in an axial spiral direction of the cam cylinder (3200); The first limit pin (3310) is located in the first linear limit groove (3110) and the first curved slide groove (3210), and the second limit pin (3410) is located in the second linear limit groove (3120) and the second curved slide groove (3220), so that when the cam cylinder (3200) rotates relative to the guide groove cylinder (3100), the first curved slide groove (3210) and the second curved slide groove (3220) can drive the zoom lens group (3300) and the compensation lens group (3400) to move axially respectively.

9. The projection system according to claim 8, wherein: The cam cylinder (3200) includes a first end (3230) and a second end (3240), the first curved slide groove (3210) and the second curved slide groove (3220) are arranged in sequence along the first end (3230) toward the second end (3240), and the end of the first curved slide groove (3210) close to the first end (3230) is connected to the end surface of the first end (3230).

10. The projection system according to claim 9, wherein: The cam cylinder (3200) is provided with a mounting hole (3250) communicating with its inner and outer surfaces, the mounting hole (3250) corresponding to the second limiting pin (3410), and the mounting hole (3250) is located at the end point of the second curved sliding groove (3220).

11. The projection system according to claim 8, wherein The zoom projection lens comprises a first driving mechanism, the first driving mechanism being mounted on the guide groove cylinder (3100), and the first driving mechanism being used to drive the cam cylinder (3200) to rotate relative to the guide groove cylinder (3100).

12. The projection system according to claim 11, wherein: A first ring gear (3510) is provided on the cam cylinder (3200), and the first driving mechanism includes a first motor (3530) and a first gear (3520) connected to an output shaft of the first motor (3530), and the first gear (3520) is meshed with the first ring gear (3510).

13. The projection system according to claim 8, wherein: The zoom projection lens further comprises a second driving mechanism, the second driving mechanism being connected to the guide groove cylinder (3100), and the second driving mechanism being used to drive the guide groove cylinder (3100) to move along its axial direction.

14. The projection system according to claim 13, wherein: The guide groove cylinder (3100) is provided with a third curved sliding groove (3130) and a third linear limiting groove (3140) that are spirally bent along its axial direction; The second driving mechanism comprises a moving directional cylinder (3610) and a whole mirror moving ring (3620); the moving directional cylinder (3610) is sleeved on the outside of the guide groove cylinder (3100); the moving directional cylinder (3610) is provided with an arc-shaped sliding groove (3611) connecting the inner and outer walls thereof; the arc-shaped sliding groove (3611) extends along the circumference of the moving directional cylinder (3610); The inner wall of the movement-orienting cylinder (3610) is provided with a third limiting pin (3612) extending inward, and the third limiting pin (3612) is located in the third linear limiting groove (3140); The whole mirror movement ring (3620) is sleeved on the outside of the movement orientation cylinder (3610), and a fourth limit pin (3621) extending inward is provided on the inner wall of the whole mirror movement ring (3620). The fourth limit pin (3621) passes through the arc-shaped slide groove (3611) and is located in the third curved slide groove (3130).

15. The projection system according to claim 14, wherein: The second driving mechanism further includes a second gear ring (3710) arranged on the outer wall of the whole mirror motion ring (3620), and a second motor (3730), the output end of the second motor (3730) is connected to the second gear (3720), and the second gear ring (3710) is meshed with the second gear (3720).

16. The projection system according to claim 13, wherein: The second driving mechanism comprises a linear driving module, and a linear driving end of the linear driving module is connected to the guide groove cylinder (3100).

17. The projection system according to claim 1, wherein: The shape of the preset projection image is a square.

18. The projection system according to claim 1, wherein: The zoom projection lens comprises a compensation lens group (3400) and a variable magnification lens group (3300) arranged at intervals; In step S3, the divergence angle of the output light of the zoom projection lens is changed by changing the positions of the compensation lens group (3400) and the magnification lens group (3300) on the optical axis.

19. The projection system according to claim 18, wherein: The zoom projection lens further comprises a first meniscus lens (1) located on the light-emitting side of the zoom lens group (3300), wherein the first meniscus lens (1) comprises a light-emitting curved surface S1 convex toward the light-emitting side, and a light-entering curved surface S2 concave toward the light-emitting side.

20. The projection system according to claim 19, wherein: The variable magnification lens group (3300) comprises a second meniscus lens (3) and a biconcave lens (2) arranged in sequence along the direction of the emitted light; The biconcave lens (2) comprises a light-emitting curved surface S3 concave toward the light-entering side, and a light-entering curved surface S4 concave toward the light-exiting side; The second meniscus lens (3) comprises a light-emitting curved surface S5 that is concave toward the light-entering side, and a light-entering curved surface S6 that is convex toward the light-exiting side.

21. The projection system according to claim 20, wherein: The compensation lens group (3400) comprises a plano-convex lens (7), a third meniscus lens (6), and a biconvex lens (5) arranged in sequence in the reverse direction of the outgoing light; The biconvex lens (5) comprises a light-emitting curved surface S7 convex toward the light-emitting side, and a light-entering curved surface S8 convex toward the light-entering side; The third meniscus lens (6) comprises a light-emitting curved surface S9 that is concave toward the light-entering side, and a light-entering curved surface S10 that is convex toward the light-entering side; The plano-convex lens (7) comprises a light-emitting curved surface S11 convex toward the light-emitting side, and a light-entering plane S12.

22. The projection system according to claim 21, wherein: The focal length f1 of the first meniscus lens (1) is in the range of 116mm<f1<118mm; the focal length f2 of the biconcave lens (2) is in the range of -19mm<f2<-17mm; the focal length f3 of the second meniscus lens (3) is in the range of 57mm<f3<59mm; the focal length f4 of the biconvex lens (5) is in the range of 20mm<f4<22mm; the focal length f5 of the third meniscus lens (6) is in the range of -38mm<f5<-36mm; and the focal length f6 of the plano-convex lens (7) is in the range of 39mm<f6<41mm.

23. The projection system according to claim 22, wherein: The axial distance between the light exit curved surface S1 and the light incident curved surface S2 is greater than 4 mm and less than 6 mm; The axial distance between the light incident curved surface S2 and the light exit curved surface S3 is greater than 3 mm and less than 5 mm; The axial distance between the light exit curved surface S3 and the light incident curved surface S4 is greater than 1 mm and less than 2 mm; The axial distance between the light incident curved surface S4 and the light exit curved surface S5 is greater than 1.8 mm and less than 3.8 mm; The axial distance between the light exit curved surface S5 and the light incident curved surface S6 is greater than 2.5 mm and less than 4.5 mm; The axial distance between the light exit curved surface S7 and the light incident curved surface S8 is greater than 4 mm and less than 6 mm; The axial distance between the light incident curved surface S8 and the light exit curved surface S9 is greater than 0.5 mm and less than 1.5 mm; The axial distance between the light exit curved surface S9 and the light incident curved surface S10 is greater than 1 mm and less than 2 mm; The axial distance between the light incident curved surface S10 and the light exit curved surface S11 is greater than 0.25 mm and less than 0.75 mm; The axial distance between the light emitting curved surface S11 and the light incident plane S12 is greater than 2.5 mm and less than 4.5 mm.

24. The projection system according to claim 23, wherein: The light emitting curved surface S1 is a spherical surface, and the radius of curvature is greater than 24 mm and less than 26 mm; The light incident curved surface S2 is a spherical surface, and the radius of curvature is greater than 35 mm and less than 37 mm; The light-emitting curved surface S3 is a spherical surface, and the radius of curvature is greater than -13 mm and less than -11 mm; The light incident curved surface S4 is a spherical surface, and the radius of curvature is greater than 76 mm and less than 80 mm; The light-emitting curved surface S5 is a spherical surface, and the radius of curvature is greater than -15 mm and less than -13 mm; The light incident curved surface S6 is a spherical surface, and the radius of curvature is greater than -12 mm and less than -10 mm; The light emitting curved surface S7 is a spherical surface, and the radius of curvature is greater than 34 mm and less than 36 mm; The light incident curved surface S8 is a spherical surface, and the radius of curvature is greater than -20 mm and less than -18 mm; The light-emitting curved surface S9 is a spherical surface, and the radius of curvature is greater than -18 mm and less than -16 mm; The light incident curved surface S10 is a spherical surface, and the radius of curvature is greater than -40 mm and less than -38 mm; The light-emitting curved surface S11 is a spherical surface, and the radius of curvature is greater than 22 mm and less than 24 mm.

Images