1416 results about "Axial distance" patented technology

A system includes a first electrical connector configured to removably couple with a second electrical connector. The first electrical connector includes a housing having an axial opening. The first connector also includes a movable support disposed inside the housing. The movable support includes a first connector portion having a first electrical path with a first radial contact electrically coupled to a first axial contact. The first electrical connector also includes a stationary support disposed inside the housing. The stationary support includes a first mating connector portion having a first mating electrical path with a first mating axial contact coupled to a first electrical cable. The first electrical connector also includes a shuttle pin configured to engage with the second electrical connector through the axial opening in the housing. The shuttle pin is configured to move along a first axial path of travel in a first connection stage. The movable support is configured to move along a second axial path of travel in a second connection stage. The first connection stage is configured to engage the first radial contact of the first electrical connector with a first mating radial contact of the second electrical connector at a first axial position in response to the first axial path of travel. The second connection stage is configured to engage the first axial contact with the first mating axial contact over a first axial distance in response to the second axial path of travel.

The invention discloses an artificial biological heart valve device, and relates to the technical field of heart surgeries. Valve leaflets are fixedly mounted on a supporting assembly, so that the valve leaflets are supported and limited; the first edge (supporting wall 42) of the suture ring is used for suturing and fixing with the supporting assembly, and the second edge (suturing wall 41) is used for suturing with the tissue ring; the wall face of the suture ring has extension in the axial direction, so that an axial distance exists between the first edge (supporting wall 42) and the second edge (suture wall 41), the first edge (supporting wall 42) is located outside the ventricle, the wall face of the suture ring supports the supporting assembly in the axial direction, and the supporting assembly is made to be away from the ventricle by means of the extension size of the wall face of the suture ring in the axial direction. By the adoption of the structure, the thickness of the suture ring does not need to be additionally increased, and the axial position of the supporting assembly cannot be affected during suture and tensioning.

The utility model discloses a quantitative dosing prefilled syringe, which comprises a syringe filled with a preset amount of liquid medicine in advance, and further comprises an injection push rod capable of being inserted into the syringe in an axial moving manner, and a dosage adjusting mechanism capable of being arranged on the syringe in an axial moving manner, the injection push rod is used for pushing liquid medicine in the injection cylinder to flow out, and the dosage adjusting mechanism is used for abutting against the limiting piece so as to limit the pushing stroke of the injection push rod. Thus, when a medical worker needs to inject a small dose at a time, the medical worker only needs to adjust the axial position of the dose adjusting mechanism according to the target axial distance corresponding to the target injection dose, then the injection push rod is pressed to start injection till the limiting piece abuts against the dose adjusting mechanism, and the maximum pushing stroke is achieved; therefore, it can be ensured that the actual injection dosage is equal to the target injection dosage, accurate injection of any dosage can be achieved, the requirement for accurate injection of single-time tiny dosage is met, and the treatment effect of a multi-injection administration mode is ensured.

The invention provides a same-side input double-shaft compressor tester rotor concentricity reserving method, which belongs to aero-engine tests and comprises the following steps: determining thermal expansion displacement of an exhaust passage and a gear box support structure in a same-side input double-shaft compressor tester, according to the thermal expansion displacement and the axial distance, the thermal expansion displacement of the input flange of the biaxial compressor test piece and the thermal expansion displacement of the output flange of the gearbox are obtained through calculation, and then the estimated cold and hot state concentricity variation is obtained; according to the estimated cold and hot state concentricity variable quantity, the estimated cold state concentricity is calculated by taking the hot state concentricity as zero, and the rotor of the double-shaft compressor tester is arranged according to the estimated cold state concentricity; vibration measuring points and bearing temperature measuring points are arranged for testing, the operation state of the double-shaft compressor tester is judged through the vibration measuring points and the bearing temperature measuring points, and if the operation state meets the requirement, the estimated cold-state concentricity meets the requirement; and if the operation state does not meet the requirement, the estimated cold state concentricity is corrected.

A photographing optical lens assembly comprising six lens elements (E1, E2, E3, E4, E5 and E6), wherein the six lens elements (E1, E2, E3, E4, E5 and E6) are, in order from an object side to an image side along an optical path, a first lens element (E1), a second lens element (E2), a third lens element (E3), a fourth lens element (E4), a fifth lens element (E5) and a sixth lens element (E6), and each of the six lens elements (E1, E2, E3, E4, E5 and E6) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the first lens element (E1) has a negative refractive power, the object-side surface of the second lens element (E2) is concave in a paraxial region thereof, and the image-side surface of the third lens element (E3) is concave in a paraxial region thereof; and wherein an axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the sixth lens element (E6) is TD, a focal length of the photographing optical lens assembly is f, a focal length of the fifth lens element (E5) is f5, an axial distance between the fifth lens element (E5) and the sixth lens element (E6) is T56, an axial distance between the object-side surface of the first lens element (E1) and an image surface (IMG) is TL, a maximum image height of the photographing optical lens assembly is ImgH, and the following conditions are met: 2.20 < TD / f < 4.50 ; − 0.80 < f / f5 < 0.20 ; 1.00 < TD / T56 < 35.00 ; and 0.50 < TL / ImgH < 4.00.

The invention discloses an upper pen container assembly of an injection pen and the injection pen. A dose adjustment mechanism; a rotating wheel of the driving mechanism is located between the driving wheel and the power rod, an inner ring of the rotating wheel is in threaded connection with the screw, and an outer ring can rotate relative to the upper pen container, is in circumferential limiting connection with the sleeve and can move in the axis direction relative to the sleeve; the driving wheel and the sleeve are connected in a circumferential limiting manner, and during rotation, the driving wheel and the screw are limited in the circumferential direction, and the driving wheel and the bottle rack cover can rotate relatively; when the driving wheel and the sleeve rotate relatively, the bottle rack cover and the driving wheel are limited in the circumferential direction, and the driving wheel circumferentially limits the screw to rotate along with the rotating wheel. In the process of adjusting the dosage of injection medicine, the screw rod and the sleeve can guarantee the position stability under the supporting action of the power rod, the bottle rack cover and the rotating wheel, the rotating wheel can move in the direction close to the button in the axial direction, a distance is formed between the rotating wheel and the upper pen container in the axial direction, the stability of the position of the screw rod is further improved, and the service life is prolonged. And the rotation stability of the sleeve is improved.

The invention provides an optical lens and electronic equipment. The optical lens sequentially comprises a first lens with negative focal power, a second lens with positive focal power, a third lens with positive focal power, a fourth lens, a fifth lens and a sixth lens from a first side to a second side along an optical axis, the first side surface of the fifth lens is a convex surface, and the second side surface is a concave surface; the first side surface of the sixth lens is a convex surface, and the second side surface is a concave surface; the number of lenses with focal power of the optical lens is six. The optical lens satisfies the following conditions: 0.07 < = T12 / TTL < = 0.4, 0.1 < = R9 / TTL < = 2, and 0.05 < = R10 / TTL < = 2, where T12 is the axial distance from the second side surface of the first lens to the first side surface of the second lens, TTL is the total optical length of the optical lens, R9 is the radius of curvature of the first side surface of the fifth lens, and R10 is the radius of curvature of the second side surface of the fifth lens.

Device (10) for compressing empty containers, in particular beverage bottles or cans made of plastic, for example PET, or tinplate, comprising: - two rotary rollers (12a, 12b) which can be driven in opposite directions to compress containers fed between each other; wherein: - the respective axes of rotation (L12a, L12b) of the rotary drums (12a, 12b) are aligned parallel to each other and spaced apart by an axis distance (K); - the rotary rollers (12a, 12b) each comprise a circular cylindrical roller body (14) and a plurality of disc-shaped tooth groups (16) spaced apart from each other in the axial direction of the roller body (14); - each of the tooth groups (16) comprises an equal number of circumferentially spaced teeth (18), each extending radially from a tooth base (18a) to a tip (18b), wherein an inner radius (R1) of the rotating drum (12a, 12b) is defined at the tooth base (18a) and an outer radius (R2) of the rotating drum (12a, 12b) is defined at the tip (18b); - the respective tooth groups (16) of the two rotating rollers (12a, 12b) are axially offset from each other in such a way that they engage between each other; - the inner radius (R1) and the outer radius (R2) together are larger than the center-to-center distance (K), but the center-to-center distance (K) is larger than twice the inner radius (R1); and - the width (c) of each tooth (18) at the tooth base (18a) is less than or equal to half the distance (b) between adjacent teeth (18) within a group of teeth (16) at the tooth base (18a).

In a disc brake (2) with a brake disc (1) having a virtual main disc plane (11), a disc hub (3), and two friction rings (5, 6) mounted on the disc hub (3) so as to be non-rotatable about an axis of rotation (4), arranged at an axial distance (8) from each other forming a cooling gap (7), and provided with holes (9, 10), the holes (9, 10) through the friction rings (5, 6) each extend at an angle (19) between 20° and 70° to the main disc plane (11). Viewed from the cooling gap (7), either all holes (9, 10) through both friction rings (5, 6) extend away from the axis of rotation (4) or all holes (9, 10) through both friction rings (5, 6) extend towards the axis of rotation (4).

The invention relates to an atrial septum puncture system, and belongs to the technical field of medical instruments. The atrial septum puncture system comprises a conveying sheath assembly, a dilator assembly and a puncture guide wire. The dilator assembly comprises a dilator, a puncture needle and a control handle. The conveying sheath assembly, the dilator assembly and the puncture guide wire are combined into the atrial septum puncture system, puncture operation is more convenient and safer, and the puncture guide wire and a puncture needle do not need to be frequently exchanged in the puncture operation process; according to the dilator assembly, the control handle comprises the moving part and the limiting part, the moving part is fixedly connected with the near end of the puncture needle, the moving part is used for driving the puncture needle to move in the axial direction of the moving part, and a user can control the puncture needle conveniently; the limiting step is arranged on the outer wall of the moving part, and the axial distance between the near end of the limiting part and the limiting step is 0.5-10 mm, so that the distance of a puncture needle extending out of the dilator can be limited, and the safety of puncture operation can be guaranteed.

The invention provides an optical imaging lens, the optical imaging lens has three lenses with focal power, and the optical imaging lens comprises a lens group, a bearing element group and a lens barrel, the axial distance T12 from the image side surface of the first lens to the object side surface of the second lens and the axial distance T23 from the image side surface of the second lens to the object side surface of the third lens meet the following conditions: 1.4 lt; t12 / T23lt; 2.0); the inner diameter d2m of the image side surface of the second bearing element, the inner diameter d1m of the image side surface of the first bearing element and the distance EP12 from the image side surface of the first bearing element to the object side surface of the second bearing element along the direction of the optical axis of the optical imaging lens meet the following conditions: 0.25 lt; (d2m-d1m) / EP12lt; and 1.5. The problem that miniaturization and high imaging quality of an optical imaging lens in the prior art cannot be considered at the same time is solved.

The utility model relates to an ultra wide angle pick-up lens suitable for a vehicle-mounted OMS system, an optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens, the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a meniscus convex positive lens, the fourth lens is a meniscus convex positive lens, and the seventh lens is a meniscus convex positive lens. The fourth lens is a meniscus concave negative lens, the fifth lens is a biconvex positive lens, the sixth lens is a biconcave negative lens, the seventh lens is a biconvex positive lens, the sixth lens and the seventh lens form a cemented lens group, the first lens and the fifth lens are made of glass materials, and the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are plastic aspheric lenses. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the field angle of the lens is enlarged while the imaging performance requirement of the lens is met, so that the low-cost ultra-wide-angle camera lens suitable for a vehicle-mounted OMS system is realized.

A wheel includes a boss, a rim, and a web. The rim includes a tread and a flange. A center of the rim in the axial direction of the wheel is disposed closer to the flange in the axial direction than a center of the boss in the axial direction is. The web has a plate-thickness center line that has a linear shape when the wheel is viewed in its longitudinal section. When an angle that the plate-thickness center line forms with the axial direction is denoted by a, a distance in the axial direction from a side face of the rim to an outer end of the plate-thickness center line is denoted by Pw, a length of the rim in the axial direction is denoted by Wr, and Pw / Wr is denoted by L, the wheel satisfies the expression L≥0.0223α−1.363. Where, the angle α is 90° or less.

An induction motor rotor includes a magnetic metal core; and an electrically conductive metal contiguous with the magnetic metal core. The electrically conductive metal includes rotor bars extending along the magnetic metal core and end segments formed onto opposite ends of the rotor bars. Each of the end segments includes a base section extending a first axial distance from the magnetic metal core and a protrusion extending a second axial distance from the magnetic metal core. The second axial distance is greater than the first axial distance. The induction motor rotor also includes a metal ring positioned on an outer circumferential surface of each of the end segments to prevent the end segments from separating from the rotor bars.

The invention relates to an airbag, which is configured to be set from an uninflated state to an inflated state to protect an occupant of a vehicle. According to the invention, it is provided that the airbag has at least two fabric layers which are connected to one another in such a way that a central inflow region forming a first airbag chamber and at least two wing regions forming respective second airbag chambers and extending radially from the inflow region are formed, so that during the inflation operation of the airbag a gas can first flow into the central inflow region and then from the central inflow region into the respective wing regions, distal end portions of the at least two wing regions being connected to one another via a flat tensioning element, so that the distal end portions move axially away from the central inflow region during the inflation operation of the airbag and, in the inflated state of the airbag, radially tension the flat tensioning element at an axial distance from the central inflow region.

The invention discloses an optical imaging lens, which comprises a first lens group, a second lens group and a plurality of bearing pieces, the first lens group and the second lens group are sequentially arranged from an object side to an image side along an optical axis, and the first lens group is accommodated in a first lens barrel and comprises a first lens and a second lens; the second lens group is accommodated in the second lens barrel and comprises third to sixth lenses; the first to sixth lenses are sequentially arranged from the object side to the image side along the optical axis. A third bearing piece in contact with the object side face of the fourth lens is arranged between the third lens and the fourth lens, and a fourth bearing piece in contact with the object side face of the fifth lens is arranged between the fourth lens and the fifth lens. The maximum height LB of the second lens cone, the combined focal length F2 of the second lens group, the effective focal length f4 of the fourth lens and the distance EP34 of the third bearing piece and the fourth bearing piece on the optical axis; the on-axis distance SAG41 from the intersection point of the object side surface of the fourth lens and the optical axis to the vertex of the non-light-transmitting part of the object side surface of the fourth lens and the on-axis distance SAG42 from the intersection point of the image side surface of the fourth lens and the optical axis to the vertex of the non-light-transmitting part of the image side surface of the fourth lens meet the following conditions: 0.5 lt; lB / F2lt; 1.5, 1.6 lt, 1.5, 1.6 lt; f4 / F2lt; 1.8, and 0.5 lt; eP34 / SAG41 + SAG42lt, and SAG41 + SAG42 < 2.

A method for balancing a rotor of an external rotor motor is described, wherein the rotor has a short-circuit ring (1), permanent magnets (2) attached to the inside of the short-circuit ring (1), and a carrier (3) which is attached to the short-circuit ring (1) and forms a hub (4) for a shaft, and wherein, in order to eliminate an imbalance, material is removed from the carrier (3) at several points which are arranged at an axial distance from each other.

The utility model relates to a high-brightness low-cost DMD welcome lamp lens. An optical system of the lens is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens and a fifth lens which are sequentially arranged from left to right along a light incident light path. The lenses are made of plastic and glass materials, the first lens, the second lens, the third lens and the fourth lens are plastic aspheric lenses, and the fifth lens is a glass spherical lens. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the imaging performance requirement of the lens is met, the total length of the lens and the radial size of each lens are reduced, and the miniaturization of the lens group is realized.

The utility model discloses an optical imaging system. The optical imaging system comprises a lens cone, an imaging group and a second spacing element, wherein the imaging group and the second spacing element are arranged in the lens cone. The imaging group sequentially comprises a linear polarization film, a reflective polarization element, a quarter-wave plate, a first lens, a second lens, a third lens, a fourth lens and a partial reflection layer from the first side to the second side along the optical axis; wherein the first lens and the second lens are glued, and the third lens and the fourth lens are glued. The second spacer element is disposed on the second side of the second lens and is in contact with the second side of the second lens. Wherein the outer diameter D0m of the second side end face of the lens barrel and the outer diameter D2m of the second side face of the second spacing element meet the condition that D0m-D2m is larger than or equal to 4.51 mm and smaller than or equal to 5.8 mm; the inner diameter d2m of the second side surface of the second spacing element, the inner diameter d2s of the first side surface of the second spacing element, and the axial distance T23 from the second side surface of the second lens to the first side surface of the third lens satisfy the following formula: (d2m-d2s) / T23 is greater than or equal to 0.97 and less than or equal to 2.79.

The invention discloses an optical imaging system. The optical imaging system comprises a lens cone, an imaging group and a second spacing element, wherein the imaging group and the second spacing element are arranged in the lens cone. The imaging group sequentially comprises a linear polarization film, a reflective polarization element, a quarter-wave plate, a first lens, a second lens, a third lens, a fourth lens and a partial reflection layer from the first side to the second side along the optical axis; wherein the first lens and the second lens are glued, and the third lens and the fourth lens are glued. The second spacer element is disposed on the second side of the second lens and is in contact with the second side of the second lens. Wherein the outer diameter D0m of the second side end face of the lens barrel and the outer diameter D2m of the second side face of the second spacing element meet the condition that D0m-D2m is larger than or equal to 4.51 mm and smaller than or equal to 5.8 mm; the inner diameter d2m of the second side surface of the second spacing element, the inner diameter d2s of the first side surface of the second spacing element, and the axial distance T23 from the second side surface of the second lens to the first side surface of the third lens satisfy the following formula: (d2m-d2s) / T23 is greater than or equal to 0.97 and less than or equal to 2.79.

A robot joint module adopting a cantilever type rotating shaft comprises a torque sensor, a speed reducer, a motor and an encoder assembly, the speed reducer comprises an input part and an output part, the output part of the speed reducer is hollow, one end of the output part of the speed reducer is connected with the torque sensor, and the input part of the speed reducer is fixed to a rotor of the motor; the motor comprises a machine shell, a stator and a rotor, a supporting frame is arranged on the machine shell, the rotor is connected to the supporting frame through a bearing, the encoder assembly comprises an input end coded disc, an output end coded disc and a circuit board, the rotor is connected with the input end coded disc, and the other end of the output part of the speed reducer penetrates through the rotor to be connected with the output end coded disc. According to the invention, only one end of the motor rotating shaft is fixed on the motor shell, and a cantilever mechanism is adopted, so that the axial distance can be shortened, and the process cost is saved. And a torque sensor is integrated at the output flange, so that the output torque can be directly measured.

The utility model relates to a DMD welcome lamp lens with short total length, the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens from left to right along a light incident light path, the lenses are made of glass materials, the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are glass spherical lenses, the second lens is a glass aspheric lens, wherein the third lens and the fourth lens, and the fifth lens and the sixth lens form a balsaming lens group. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the imaging performance requirement of the lens is met, the total length of the lens and the radial size of each lens are reduced, and a 33 mm lens group is formed.

The invention relates to a multi-stage centrifugal pump transition flow channel and a flow channel design method. The transition flow channel comprises a delivery chamber, a flow channel diffusion section and a suction chamber. An outlet of the delivery chamber located at the upper stage is communicated with an inlet of the flow channel diffusion section, and an outlet of the flow channel diffusion section is communicated with an inlet of the suction chamber; the delivery chamber is of a double-volute structure and is symmetrically arranged about the center line of the volute, and the sum of the areas of the two symmetrical throats is equal to the area of a single volute; the flow channel diffusion section obliquely penetrates through the pump body, the internal sectional area of the flow channel diffusion section is gradually increased in the direction from an inlet to an outlet until the sectional area is equal to or slightly smaller than the inlet area of the suction chamber, the flow channel diffusion section is symmetrically arranged about the center line of the volute, and the suction chamber is symmetrically arranged about the center line of the volute. The radial force can be basically balanced, so that the pump operates stably, and the noise and vibration of a unit are reduced; the radial size of the pump body is small and space is saved; the efficient range is wide; the axial distance of the transition flow channel is reduced, and the axial size of the pump body is reduced.

The invention discloses a planar interconnection connector and an integrated assembly, and belongs to the field of adapters. The first plug-in assembly is mounted on the first shell; the other side of the first shell is provided with a second shell, and the other end of the second shell is provided with a second plugging assembly. An adapter assembly is arranged on the inner sides of the first shell and the second shell; the outer side of the second shell is sleeved with an elastic piece, and the elastic piece abuts against the first shell and the second plugging assembly. When plugging is carried out, the second housing extends into the inner side of the first housing, and the switching assembly is stressed and compressed at the same time, so that the first plugging assembly and the second plugging assembly move oppositely along the same axis direction. The second shell shrinks to enter the inner side of the first shell, meanwhile, the switching assembly is stressed and compressed, the floating compression distance is formed through the two inserting structures, the compression stroke of 1 mm is guaranteed in the axial direction, and the large-axial-distance compression stroke is achieved under the condition that the inserting isolation degree is guaranteed.

The invention provides a pick-up lens. The pick-up lens comprises a lens barrel; the lens group is assembled in the lens barrel and sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from the object side to the image side; the lens group further comprises a plurality of shading elements, and the first shading element, the second shading element and the third shading element meet the condition that CP1 = CP2 = CP3; the camera lens satisfies: f1gt; 6 mm, 2 lt; fno * (EP01 / CT1) lt; 4; wherein f1 is the effective focal length of the first lens, CT1 is the center thickness of the first lens, EP01 is the axial distance from the first shading element to the object side end face of the lens barrel, fno is the F number of the camera lens, CP1 is the maximum thickness of the first shading element, CP2 is the maximum thickness of the second shading element, and CP3 is the maximum thickness of the third shading element. The camera lens solves the problem that the front-end lens of the camera lens in the prior art is easy to generate stray light.

Embodiments of a prosthetic valve delivery apparatus are disclosed. The delivery apparatus includes a first portion configured to maintain a fixed spatial relationship relative to a first end of the prosthetic valve and a second portion configured to maintain a fixed spatial relationship relative to a second end of the prosthetic valve during radial expansion of the prosthetic valve. The first portion includes one or more reference radiopaque markers and the second portion includes an indicator radiopaque marker. A position of the indicator radiopaque marker relative to the one or more reference radiopaque markers measures an axial distance between the first and second ends of the prosthetic valve indicative of a corresponding diameter of the prosthetic valve as it is radially expanded from a radially compressed state to a radially expanded state.

The invention belongs to the technical field of pupil positioning. The invention provides an OCT (optical coherence tomography)-based pupil positioning method and system, a medium, a product and a system. When the eye fundus image of the to-be-detected person is lost due to micro motion, collecting a current first frame image, collecting a second frame image after a focus is moved, and processing to obtain the axial distance between the current focus and the pupil; then, the focus is moved to a calibration position, a third frame of image is collected and processed to obtain the pupil position, the horizontal distance and the vertical distance which the focus needs to move at present are calculated, and the focus is moved to the pupil position to complete positioning by combining the axial distance between the focus and the pupil at present. According to the invention, the OCT equipment can be helped to position the pupil and obtain the fundus image again, the cost is low, and the light path light transmission is not influenced.

The invention relates to the technical field of grating detection, in particular to a non-contact grating positioning measurement platform and method.The non-contact grating positioning measurement platform is mainly composed of an axial distance measuring probe, a radial distance measuring probe, a multi-dimensional displacement adjusting table, an air floating rotary table and a control system; in the process that the air floating rotary table drives the grating to rotate, the axial distance measuring probe and the radial distance measuring probe periodically measure the distance between the axial distance measuring probe and the grating, and the control system generates an end jump error curve and an eccentric error curve according to measured data and controls the multi-dimensional displacement adjusting table in a closed-loop mode according to the end jump error curve and the eccentric error curve. And adjusting the levelness of the upper surface of the to-be-processed grating and the overlap ratio of the circle center of the to-be-processed grating and the rotation center. Non-contact measurement in the grating machining process is achieved, the problem that the grating can be damaged by traditional contact measurement is solved, and the method has extremely high application value in the actual machining process.

The utility model relates to a 3M five-piece type foresight main camera. The 3M five-piece type foresight main camera comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens and a fifth lens which are sequentially arranged from left to right along a light incident light path, the first lens is a meniscus negative lens, the object side surface of the first lens is a convex surface, and the image side surface is a concave surface; the second lens is a biconvex positive lens, the object side surface is a convex surface, and the image side surface is a convex surface; the third lens is a biconvex positive lens, the object side surface is a convex surface, and the image side surface is a convex surface; the fourth lens is a biconcave negative lens, the object side surface is a concave surface, and the image side surface is a concave surface; the fifth lens is a biconvex positive lens, and has a convex object-side surface and a convex image-side surface. According to the utility model, the design is reasonable, the structure is simple, through reasonable distribution of the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the 3M imaging performance requirement of the five-piece lens is satisfied, the total length of the lens and the radial size of each lens are reduced, and the miniaturization of the lens group is realized.

The utility model relates to a low total length 8M foresight main camera. An optical system of the main camera is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from left to right along a light incident light path. The lenses are made of plastic and glass materials, the first lens, the second lens, the fourth lens, the sixth lens and the seventh lens are glass spherical lenses, the third lens and the fifth lens are plastic aspheric lenses, and the sixth lens and the seventh lens form a balsaming lens group. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the total length of the lens and the radial size of each lens are reduced while the requirements of a front-view wide-angle camera and a front-view narrow-angle camera are replaced by the low-total-length 8M ultra-wide-angle imaging performance of the lens, and the miniaturization of the lens group is realized.