348 results about "Lenticular lens" patented technology

The utility model discloses an optical lens. The optical lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from an object plane to an image plane along an optical axis, the first lens is a negative-focal-power convex-concave lens, the second lens is a negative-focal-power concave-convex lens, the third lens is a positive-focal-power biconvex lens, and the seventh lens is a positive-focal-power biconvex lens. The fourth lens is a positive-focal-power biconvex lens, the fifth lens is a positive-focal-power biconvex lens, the sixth lens is a negative-focal-power biconcave lens or a negative-focal-power concave-flat lens, and the seventh lens is a positive-focal-power convex-concave lens; meanwhile, the focal length F of the optical lens and the distance TTL from the center of the optical axis of the object side face of the first lens to the image face are set, TTL / F is smaller than or equal to 5.5, and under the condition that it is guaranteed that the optical lens is small in size, the high pixel, the large aperture and the large angle are achieved, and the use requirements are met.

The invention provides an objective lens system and optical observation equipment. The objective lens system comprises a fourth lens with positive focal power, a third lens with positive focal power, a second lens with negative focal power and a first lens with positive focal power which are sequentially arranged on the same optical axis from the object side; the first lens and the third lens are biconvex lenses, the second lens is a biconcave lens, the fourth lens is a balsaming lens, and the image side surface of the fourth lens is a convex surface; the focal length f of the objective lens system and the focal length f1 of the first lens satisfy the relationship. According to the invention, during assembly, the tolerance requirement is low, installation and adjustment are more facilitated, the field of view is larger, the vignetting is smaller, the number of lenses is smaller, and the cost performance is higher.

An electronic device may include a lenticular display. The lenticular display may have a lenticular lens film formed over an array of pixels. A plurality of lenticular lenses may extend across the length of the display. The lenticular lenses may be configured to enable stereoscopic viewing of the display such that a viewer perceives three-dimensional images. Crosstalk between viewing zones and disparity between images received from different viewing zones may result in disparity-caused shifts in images perceived by viewer of the lenticular display. To mitigate these disparity-caused shifts, compensation circuitry may be included in the display pipeline circuitry. The compensation circuitry may include stored disparity-caused shift calibration information that is used for the compensation. The stored disparity-caused shift calibration information may be a polynomial function that outputs a magnitude of disparity-caused shift for a given pixel location.

A lens sheet and a lamp for a vehicle. The lamp includes a light source part and a lens sheet that outputs the light input from the light source part and that forms different lighting images according to viewing angles, the lens sheet includes a printed pattern layer, on which a specific pattern image is printed, and a lenticular lens that form the different lighting images according to the viewing angles by diffusing the light that passed through the pattern image, the lenticular lens includes a plurality of diffusion lenses, and at least some of the plurality of diffusion lenses have different curvatures.

An autostereoscopic display includes a light-emitting panel and a lenticular array in which a focal length of a lenticular lens is different from its thickness. For an intersection of a given row of light-emitting cells and a given lenticular lens, a given viewing direction from a given eye toward said intersection is determined. From light-emitting cells arranged on the given row and on whose optical path the given lenticular lens lies, a set of light-emitting cells whose light travels toward the given eye is determined. Corresponding regions on a curved surface of the given lenticular lens through which light from individual light-emitting cells of the set pass toward the given eye are identified and mapped to respective pixel locations in an image to be presented. Pixel values of pixels located at these pixel locations in the image are retrieved and used to generate an output image for display.

Techniques are disclosed relating to user authentication. In some embodiments, a first device includes an authentication system configured to store an identity of a user of the first device and detect a visual indication presented on a display of a second device in response to a successful biometric authentication of a user of the second device. Based on the visual indication, the authentication system determines that the authenticated user of the second device corresponds to the identity of the user of the first device. In some embodiments, the second device includes a display with a lenticular lens and, in response the user has been authenticated, displays a plurality of visual indications including a first visual indication visible from a first viewing angle and a second visual indication visible from a second viewing angle.

The present invention discloses a short-wave infrared telescope for short-distance detection, which is a coaxial transmissive optical system with a working wavelength range of 1000nm to 2500nm. It includes a window glass and eight spherical lenses. Along the light incident direction, they are successively the first plane window plate, the second negative meniscus lens, the third positive meniscus lens, the fourth positive meniscus lens, the aperture stop, the fifth positive biconvex lens, the sixth negative meniscus lens, the seventh positive biconvex lens, the eighth negative biconvex lens, and the ninth positive biconvex lens. The present invention is applicable to the short-wave infrared band of 1000nm to 2500nm; applicable to short detection distances of 1050mm to 1500mm; has a large viewing angle and a small system volume; the image-space telecentric system makes the image plane illumination uniform and is easy to be spliced with the spectrometer splitting system; within the range of -10°C to 40°C, the imaging quality is close to the diffraction limit; the processing and manufacturing costs are low; the energy utilization rate is high, the light-gathering ability is strong, and the thermal adaptability is good.

The utility model provides an optical system and optical equipment. The optical system comprises a display screen, a first lens, a second lens and a third lens which are sequentially arranged along an optical axis. A first pancake composite film is arranged on the surface of the side, close to the first lens, of the display screen. The first lens is a convex-concave lens with negative focal power, and a semi-transparent and semi-reflective film is arranged on the surface of one side, close to the display screen, of the first lens. And the second lens is a biconvex lens with positive focal power. The third lens is a plano-convex lens with positive focal power, and a second pancake composite film is arranged on the surface of one side, close to the second lens, of the third lens. And the exit pupil distance of the optical system is 30-40 mm. The optical system and the optical device provided by the utility model have a large object plane and a large exit pupil distance, and can effectively improve the user experience.

The invention discloses an objective lens imaging system and optical detection equipment. The objective lens imaging system comprises a first concave-convex lens, a first lens group, a second lens group, a fourth concave-convex lens and a plano-convex lens which are sequentially arranged on the same optical axis from an object side to an image side. The convex surface of the first concave-convex lens faces the object side, the plane of the plano-convex lens faces the image side, and the convex surface faces the concave surface of the fourth concave-convex lens; the first lens group comprises a first biconcave lens and a first biconvex lens, the second concave surface of the first biconcave lens is attached to the first convex surface of the first biconvex lens, and the first concave surface of the first biconcave lens faces the concave surface of the first concave-convex lens; the second lens group comprises a second biconvex lens, a second concave-convex lens and a third concave-convex lens, the second concave-convex lens and the third concave-convex lens are attached to the two convex faces of the second biconvex lens, the convex face of the second concave-convex lens faces the second convex face of the first biconvex lens, and the convex face of the third concave-convex lens faces the convex face of the fourth concave-convex lens. The invention has the advantages of small volume, small field loss and excellent resolution.

The invention provides a deep ultraviolet infinite imaging detection objective lens, belongs to the technical field of optics, and solves the problem that tiny defects in a semiconductor device are difficult to discover, the objective lens comprises a first lens group, a diaphragm, a second lens group and a third lens group which are sequentially arranged from an object plane in the optical axis direction, the first lens group has positive focal power, and the second lens group has negative focal power. Comprising a first meniscus lens, a second meniscus lens, a third meniscus lens, a fourth meniscus lens, a fifth meniscus lens and a sixth meniscus lens. The second lens group has positive focal power and comprises a seventh meniscus lens, an eighth meniscus lens, a ninth meniscus lens, a first biconvex lens and a second biconvex lens; the third lens group has negative focal power and comprises a first biconcave lens, a tenth meniscus lens, a second biconcave lens and an eleventh meniscus lens, and finally light emitted from the third lens group is parallel light. According to the invention, the change of different multiplying power can be realized, the method is suitable for a deep ultraviolet wave band with a very short wavelength, the numerical aperture is larger, and the resolution is higher.

A display device includes a light-emitting panel comprising a plurality of pixels, wherein a given pixel comprises sub-pixels of at least two different colours (R, G, B, W) that are arranged sequentially along a first direction (A-B, H-I, M-N, K-L, Y-Z, U-V). The display device further includes a lenticular array arranged on an optical path of the light-emitting panel, the lenticular array including a plurality of lenticular lenses, wherein a longitudinal axis (X-Y) of a given lenticular lens aligns with the first direction. A processor is configured to generate drive signals for the plurality of pixels, based on a light field image to be displayed and to drive the plurality of pixels using the drive signals to display the light field image.

The invention discloses a fluorescent confocal microscopic endoscopic imaging lens, which comprises three groups of doublet lenses, specifically comprising a first lens group, a second lens group and a third lens group, the first lens group comprises a plano-concave lens and a first biconvex lens which are sequentially arranged from an object space side to an image space side, and the second lens group comprises a plano-concave lens and a second biconvex lens which are sequentially arranged from an object space side to an image space side; the detector is used for collecting fluorescence signals emitted by an object space and adjusting light angles; the second lens group comprises a first negative meniscus lens and a second biconvex lens, and is used for relaying transmission light and balancing aberration so as to gently transition a light angle; and the third lens group comprises a second negative meniscus lens and a positive meniscus lens and is used for focusing the light to the end face of the optical fiber bundle. The lens is compact in structure, reasonable in light path matching and suitable for human tissue close imaging scenes, has the advantages of being high in resolution, low in distortion, excellent in chromatic aberration control and the like, and is suitable for digestive tract early cancer diagnosis and confocal imaging system integration.

An optical system of binoculars includes a first object biconvex lens of positive focal power, a second object meniscus lens of negative focal power, a third object meniscus lens of positive focal power, a fourth object meniscus lens of negative focal power, a half pentaprism, a roof prism, a first eyepiece biconcave lens of negative focal power, a second eyepiece biconvex lens of positive focal power, a third eyepiece biconvex lens of positive focal power, a fourth eyepiece meniscus lens of negative focal power, and a fifth eyepiece meniscus lens of positive focal power. These are sequentially arranged along an optical axis direction from an object side to an observation side. When focusing, the fourth object lens moves along the optical axis direction. The binoculars include an exit pupil diameter range of 3.5 mm-4.5 mm, an exit pupil distance range of 15-18 mm, and a field angle range of 6°-6.5°.

An optical lens and a related device are applied to the technical field of optical imaging. The optical lens comprises at least seven lenses which are sequentially and coaxially arranged from an object side to an image side, the at least seven lenses comprise at least four lenses with positive focal power and at least three lenses with negative focal power, and the at least seven lenses at least comprise two meniscus lenses, two biconcave lenses and three biconvex lenses. According to the optical lens, an optical structure of at least seven lenses is adopted, through arrangement of the shapes of the at least seven lenses and reasonable distribution of focal power, the optical lens can be shared by a laser radar and a camera, and light rays are collected and stably transmitted to a light sensing surface of the laser radar and a light sensing surface of the camera for imaging; the high resolution performance of the optical lens is improved, so that the advantage that the optical lens can be combined with the point cloud data of the laser radar and the image data of the camera is utilized, and the intelligent driving perception precision is improved.

The utility model discloses an optical imaging lens group and a scanning display device, and relates to the technical field of scanning display. The optical imaging lens group provided by the utility model comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged along a common optical axis from a first side to a second side, wherein the first side is arranged opposite to a light emitting end of an optical fiber scanner; the focal power of the first lens, the second lens and the third lens is positive, the focal power of the fourth lens is positive or negative, the image side surface of the first lens is a convex surface, the object side surface of the second lens is a concave surface, the third lens is a biconvex lens, the fourth lens is a meniscus lens and is bent towards the second side, the image side surface of the fourth lens is a convex surface, and the object side surface of the fourth lens is a concave surface.

The invention discloses a methane and carbon dioxide dry reforming reactor in the technical field of methane reforming reactors, which comprises a reaction tank, a multi-section lens column is rotatably mounted in the lower end of the reaction tank, the lower end of the reaction tank is divided into an outer heating bin and an inner reaction bin by the multi-section lens column, and a light energy introduction assembly is arranged at the upper end of the reaction tank. The light energy introduction assembly comprises a fixed lens group which comprises a biconvex lens and a biconcave lens, the biconvex lens is fixedly mounted at the upper end of the reaction tank, and the biconcave lens is mounted between the biconvex lens and the multi-section lens column; the rotating lens group is composed of a plurality of movable units, the movable units are installed on the edge of the upper end of the reaction tank at equal intervals, each movable unit comprises an installation frame and a movable convex lens, the inner reaction bin and the outer heating bin are arranged in a sleeving mode, loss in the heat transmission process is reduced, and through the effect of a multi-section lens column and a biconcave lens, the heat transfer efficiency is improved. And the guided light energy is dispersed, so that the light energy can be uniformly distributed.

The invention discloses a large-view-field space detection optical lens. The large-view-field space detection optical lens comprises a front lens group, a diaphragm, a rear lens group and an image surface which are sequentially arranged from an object side surface to an image side surface, the front lens group filters incident light waves and forms an intermediate image; the diaphragm controls the luminous flux by adjusting the relative aperture of the diaphragm; the rear lens group amplifies the intermediate image, corrects aberration and performs optical imaging through an image surface; the front lens group comprises a first optical filter, a first negative meniscus lens, a first biconvex lens and a second biconvex lens which are sequentially arranged from a position far away from the diaphragm to a position close to the diaphragm; and the rear lens group comprises a first biconcave lens, a third biconvex lens, a fourth biconvex lens, a first positive meniscus lens, a second negative meniscus lens, a second positive meniscus lens, a third negative meniscus lens and a second optical filter which are sequentially arranged from the diaphragm to the image plane. The optical lens provided by the invention has the characteristics of circular light spot, large view field, low chromatic aberration, low distortion, high resolution and small form deviation of light spots in each view field.

The application discloses a large-view-field object-side telecentric projection imaging method and a lens for a vehicle lamp. Incident light rays are converged through two large-aperture meniscus lens; the converged light rays are reduced in size and aberration through a double cemented lens group composed of a first negative double-concave lens and a first positive double-convex lens; the light rays are further converged through a second negative meniscus lens, so that the light rays all enter a diaphragm; chromatic aberration is corrected through three cemented lenses, and aberration is further reduced, and a spherical aberration can be corrected since the aperture diaphragm is located on the object side of the three cemented lenses; the light path is further converged through two double-convex lens groups, and distortion is reduced, the light rays enter a TIR total reflection prism, pass through a protective glass, and are clearly imaged on a DMD image plane. The imaging method provided by the application can realize object-side telecentric projection imaging under a large view field through the cooperation of conditional expressions and positive and negative focal lengths between the lenses, and the imaging is high in definition.

This application provides an AR lens module and an optical display device; wherein, the AR lens module includes a lens group and a display chip arranged along the same optical axis; the lens group consists of a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged sequentially, the fifth lens being arranged adjacent to the display chip; the first lens to the fourth lens are plastic aspherical lenses, and the fifth lens is a glass aspherical lens; wherein, the first lens is a biconvex lens, and the effective focal length F1 of the first lens is 3.6mm to 4.3mm.

The invention discloses a fixed-focus high-definition long-focus infrared confocal imaging optical system, and relates to the technical field of optical imaging equipment. The optical system sequentially comprises a first meniscus lens, a first biconvex lens, a first biconcave lens, a second biconcave lens, a second biconvex lens, a second meniscus lens, a third biconvex lens, a third meniscus lens and a fourth meniscus lens from an object plane to an image plane. Wherein the first biconvex lens and the first biconcave lens form a first balsaming lens, the second biconcave lens and the second biconvex lens form a second balsaming lens, and the third biconvex lens and the third meniscus lens form a third balsaming lens; the first meniscus lens and the third meniscus lens are positive meniscus lenses, and the second meniscus lens and the fourth meniscus lens are negative meniscus lenses. The aperture diaphragm is disposed between the first biconcave lens and the second biconcave lens. According to the fixed-focus high-definition long-focus infrared confocal imaging optical system provided by the invention, large-target-surface high-definition imaging is realized only through nine lenses when the focal length is 35mm.

The invention relates to the technical field of instrument analysis, and particularly discloses a biconvex lens type diffuse reflection accessory which comprises a shell, a sample table, a biconvex lens dome and two sets of reflector assemblies, light beam channel holes are symmetrically formed in the two sides of the shell, the sample table is fixed in the shell through a positioning pin, and the biconvex lens dome and the sample table form a closed cavity. Convex lens window sheets made of zinc selenide / potassium bromide are symmetrically arranged on the two sides of the substrate; the reflector assembly is composed of an irregular trapezoid base and a wedge-shaped base which are installed on the bottom face and the top face of the shell, the irregular trapezoid base and the wedge-shaped base bear gold-plated plane reflectors respectively, two times of total reflection and focusing of incident light beams are achieved, and diffuse reflection light on the surface of a sample is recycled. Compared with the prior art, the device has the advantages of low cost, small size, simplicity and convenience in operation and maintenance and the like.

The invention relates to the technical field of vehicle-mounted lenses, and discloses a vehicle-mounted aspheric wide-angle lens which is characterized in that a main lens assembly, a diaphragm and an auxiliary lens assembly are respectively arranged from an object plane to an image plane, the main lens assembly comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens, the auxiliary lens assembly comprises a sixth lens and a seventh lens, the two ends of the first lens are plane mirrors, the inner side of the first lens is a biconvex lens, the inner side of the second lens is an inward-concave biconcave lens, the left side of the third lens is an outer convex lens, the two sides of the fourth lens are inward-concave biconcave lenses, and the right side of the fourth lens is an outer convex lens. According to the vehicle-mounted aspheric wide-angle lens, the diaphragm and the lens assembly cooperate, the diaphragm performs automatic dimming according to the light intensity, the exposure problem is avoided, the lens is made of ultra-low dispersion glass, the abbe number is larger than 55, dispersion is reduced, and the light transmittance is improved through an antireflection film.

The invention provides a 3D display method, a 3D display control device and 3D display equipment, and relates to the technical field of display. The 3D display method is applied to the 3D display device, the 3D display device comprises a display panel and a cylindrical lens array, the centers of sub-pixels of different colors in the display panel are not collinear, the display method comprises the steps that the viewpoint ordinal number of a first sub-pixel in the display panel is obtained, the ratio of the viewpoint ordinal number to the preset total viewpoint number is equal to the ratio of a first distance to a first width, and the first distance is equal to the first width; wherein the first distance is the distance between the first sub-pixel and the edge of a first lens in the cylindrical lens array in the first direction, the first width is the width of the first lens in the first direction, the first lens corresponds to the first sub-pixel, and the first direction is the arrangement direction of the cylindrical lens array; and controlling the first sub-pixel to display a corresponding viewpoint image according to the viewpoint ordinal number of the first sub-pixel in the display panel. The scheme is beneficial to popularization of combined application of a 3D naked eye technology and various display panels.

The invention relates to a naked-eye 3D display system based on a multi-layer phase modulation composite grating, belongs to the technical field of stereoscopic display, and aims to overcome the technical bottlenecks of low brightness of an existing parallax barrier grating, large crosstalk caused by large thickness of a cylindrical lens and serious dispersion of a diffraction element. The system comprises a two-dimensional display panel and a composite diffraction grating, pixel units of the display panel are composed of red, green and blue sub-pixel matrixes and are coded according to viewpoints. The composite diffraction grating is attached to the light emitting side of the panel, is made of an optical anisotropic material and is of a multi-layer structure, and a first micro-nano structure layer and a second micro-nano structure layer are sequentially arranged along a light path; the first layer is an aspherical focusing array, and the phase delay of the aspherical focusing array meets a quadric surface function so as to collimate light waves; the second layer is a dispersion compensation type deflection array, and the grating period of the second layer is accurately matched with the central wavelength of the sub-pixels, so that light of different colors is projected at the same deflection angle. According to the invention, full-color dispersion-free display is realized, the thickness of the device is less than 50 microns, and crosstalk is obviously reduced.

An imaging lens includes a first, second, third, fourth, fifth, and sixth lens. The first lens is a meniscus lens with negative refractive power and includes a convex surface facing the object side and a concave surface facing the image side. The second lens has refractive power and includes a concave surface facing the object side. The third lens has refractive power and includes a convex surface facing the image side. The fourth lens has refractive power and includes a convex surface facing the image side. The fifth lens has refractive power. The sixth lens is a biconvex lens with positive refractive power. The imaging lens satisfies the condition: 87mm. 2 ≤fLL×TTL≤111mm 2 Or condition: 12 degrees / mm ≤ HFOV / fLL ≤ 17 degrees / mm; where fLL is the effective focal length of the lens closest to the image side, TTL is the distance from the object side of the first lens to the imaging surface along the optical axis, and HFOV is the half field of view of the imaging lens.

The invention relates to an athermalization optical system. The system comprises a protection window, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an optical filter, a detector window and an image plane which are sequentially arranged in the light propagation direction and share the same optical axis. The first lens is a negative meniscus lens protruding towards the object side. The second lens is a biconcave lens; the third lens is a biconvex lens; the fourth lens is a positive meniscus lens protruding towards the object side. The fifth lens is a negative meniscus lens protruding towards the object side. The sixth lens is a biconvex lens; the seventh lens is a biconcave lens; the eighth lens is a biconvex lens; the ninth lens is a negative meniscus lens protruding towards the image space. The tenth lens is a biconvex lens; the surface of each lens is a spherical surface; the diaphragm is arranged on the front surface of the sixth lens. The optical system has the advantages of large field of view, high-resolution imaging, simple and reliable structure, high assembly efficiency and capability of being produced on a large scale.

The invention relates to the field of optical display and material engineering, in particular to an optical film with a 3D light splitting function and a manufacturing method of the optical film. An optical film with a 3D light splitting function comprises a transparent optical base material and a microstructure layer integrally formed with the surface of the transparent optical base material, the microstructure layer comprises a cylindrical lens grating layer and a parallax barrier layer, and the cylindrical lens grating layer is integrally formed on the surface of the transparent optical base material. The cylindrical lens grating layer is of a micro-nano structure formed by a nano-scale grating and a micron-scale cylindrical micro-lens array; the parallax barrier layer is located on the side, away from the transparent optical base material, of the cylindrical lens grating layer. The optical film has excellent optical efficiency, wider visual angle, excellent brightness uniformity and excellent moire inhibition capability, has 2D / 3D switching, peep-proof and other functions, can adapt to light requirements of different scenes, can serve as a core display optical element to be directly integrated in various display devices, and has wide application prospects. And the application limitation of an externally-pasted protective film is broken.

A glassless stereoscopic image display device according to an embodiment of the present invention comprises: a display panel on which a plurality of rectangular pixels are arranged in a checkerboard manner; a lenticular lens which is composed of a plurality of convex lenses inclined at a predetermined angle in a predetermined direction with respect to the vertical axis of the display panel and is arranged on the front surface of the display panel; and a processor for controlling the display panel, wherein the plurality of pixels are arranged to be inclined to be parallel to a focal line formed according to the direction and angle in which the convex lenses are inclined, and the focal line is formed to be parallel to the convex lenses and is a set of focal points for a user to view a stereoscopic image.

The utility model relates to a microobjective for mineral detection, which comprises a lens cone and an optical structure arranged in the lens cone, the optical structure comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a protective window sheet which are sequentially arranged from an image plane to an object plane along an optical axis, and the protective window sheet is made of sapphire. The first lens and the second lens form a first balsaming lens group, and the third lens and the fourth lens form a second balsaming lens group; the first lens is a meniscus lens, the second lens is a biconvex lens, the third lens is a biconcave lens, the fourth lens is a biconvex lens, and the fifth lens is a plano-convex lens. According to the utility model, the design is reasonable, the optical total length of 400mm can be realized, the particle diameter below 1mu m can be distinguished, the detection requirements of mineral solution are met, and the sapphire protection window with high hardness is additionally arranged at the front end to adapt to a complex and severe solution environment so as to prevent the mineral particles from being scratched and cracked.

A large zoom ratio continuous zoom sighting lens, comprising: an objective lens group A, the objective lens group A comprising a biconvex lens A-1, a biconvex lens A-2, a biconcave lens A-3, a biconvex lens A-4, and a biconcave lens A-5; a relay lens group B, arranged between the objective lens group A and the image side, the relay lens group B comprising a front fixed group B1, a first movable group B2, a second movable group B3, and a rear fixed group B4, the front fixed group B1 being a positive meniscus lens B1-1, the first movable group B2 comprising a plurality of lenses arranged in sequence from the object side to the image side. The eyepiece C comprises a negative meniscus lens C-1, a positive meniscus lens C-2, a positive meniscus lens C-3 and a biconvex lens C-4; the diaphragm is arranged on the objective lens A-1 and coincides with the surface of the objective lens A-1.