1554 results about "Projection lens" patented technology

A vehicular lamp (100) includes a substrate (24), a light source (22a), a projection lens (30), and a light guidance body (40) having an incident surface (44a). A first space (201) is provided between a first region (441b) and the substrate (24), the first region (441b) including, on the incident surface (44a), a part of an outer peripheral edge of the incident surface (44a), and a second space (203) communicates with the first space (201) and is in contact with a second region (441c) including, on the incident surface (44a), the other part of the outer peripheral edge of the incident surface (44a). A width of the second space (203) is wider than a width of the first space (201) in an emission direction of the light from the light source (22a).

The invention provides a projection lens, which comprises seven lenses from a projection surface to an image source surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power and a fifth lens with negative focal power, the second lens has positive focal power; the surface of the image source side of the third lens is a convex surface; the surface of the projection side of the fourth lens is a concave surface, and the surface of the image source side of the fourth lens is a convex surface; the surface of the projection side of the fifth lens is a concave surface, and the surface of the image source side of the fifth lens is a concave surface; the surface of the projection side of the sixth lens is a convex surface, and the surface of the image source side of the sixth lens is a convex surface; the surface of the projection side of the seventh lens is a convex surface, and the curvature radius R7 of the surface of the projection side of the fourth lens and the curvature radius R8 of the surface of the image source side of the fourth lens meet the formula:-0.5 lt; (R7-R8) / (R7 + R8) lt; and-0.1. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

The invention provides a projection lens, which comprises seven lenses from a projection surface to an image source surface along an optical axis: a first lens with negative focal power; the second lens has positive focal power; the surface of the image source side of the third lens is a convex surface; the surface of the projection side of the fourth lens is a concave surface, and the surface of the image source side of the fourth lens is a convex surface; the surface of the image source side of the fifth lens is a concave surface; the surface of the projection side of the sixth lens is a convex surface, and the surface of the image source side of the sixth lens is a convex surface; the surface of the projection side of the seventh lens is a convex surface, and the surface of the image source side of the seventh lens is a convex surface; the surface curvature radius R7 of the projection side of the fourth lens and the surface curvature radius R8 of the image source side of the fourth lens meet the following formula:-0.6 lt; (R7-R8) / (R7 + R8) lt; 0. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

The invention provides a projection lens, which comprises six lenses in total, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from a projection surface to an image source surface, the surface of the projection side of the second lens is a convex surface, and the surface of the image source side of the second lens is a concave surface; the surface of the projection side of the third lens is a concave surface, and the surface of the image source side of the third lens is a convex surface; the surface of the projection side of the fourth lens is a concave surface; the surface of the image source side of the fifth lens is a convex surface; the surface of the projection side and the surface of the image source side of the sixth lens are convex surfaces; wherein the surface curvature radius R11 of the projection side of the sixth lens and the surface curvature radius R12 of the image source side of the sixth lens meet the following conditions:-0.8 lt; (R11 + R12) / (R11-R12) lt; and 0.1. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

The invention discloses a pixel projection lens and an automobile, and relates to the technical field of automobile illumination, the pixel projection lens is provided with an object side and an image side which are correspondingly arranged along the optical axis direction, the pixel projection lens comprises a first lens, a second lens, a third lens, a fourth lens and an image surface from the object side to the image side in sequence, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the pixel projection lens meets the following conditions: 10lt; f1lt; 20; -6 lt; f2lt; f2lt; -14.5,-14.5,-14.5; 30 lt; f3lt; f3t; 40); 35 lt; f4lt; f4t; 50; the first lens and the second lens are aspheric lenses, and the third lens and the fourth lens are glass spherical lenses. By means of the arrangement, the pixel projection lens is good in imaging quality and good in stability and can not defocus under the environment condition of-40 DEG C to 105 DEG C, and therefore it is fully guaranteed that the pixel projection lens works stably in the environment with the large temperature difference.

The utility model provides a projection lens, which comprises four lenses from a projection surface to an image source surface along an optical axis: a diaphragm; the projection side of the first lens is a convex surface, and the image source side of the first lens is a concave surface; the projection side of the second lens is a concave surface, and the image source side of the second lens is a convex surface or a concave surface; the projection side of the third lens is a convex surface, and the image source side of the third lens is a concave surface; the projection side of the fourth lens is a concave surface, and the image source side of the fourth lens is a convex surface; wherein the total optical length TTL of the projection lens meets the following conditions: 6.6 mmlt; tTLlt; the aperture number FNO of the projection lens meets the following conditions: 1.4 lt; fNOlt, FNOlt; 1.7, the total optical length TTL of the projection lens, the air gap T34 between the third lens and the fourth lens on the optical axis, and the air gap T23 between the second lens and the third lens on the optical axis meet the following conditions: 6lt; tTL / (T23-T34) lt; and 15, so that the projection lens is small in size and light in weight.

The invention, which relates to the technical field of structured light measurement, discloses a dual-frequency grating fringe projection system comprising a light source modulation group, a grating modulation group, a beam splitter prism and a projection lens. The light source modulation group comprises a first LED light source, a second LED light source, a first collimating lens group and a second collimating lens group; the grating modulation group comprises a first grating sheet, a second grating sheet, a first piezoelectric ceramic and a second piezoelectric ceramic; the first piezoelectric ceramic in the grating modulation group is connected with the first grating sheet, and the second piezoelectric ceramic is connected with the second grating sheet, so that the positions of the grating sheets are moved, and the stripe patterns at the bottoms of the grating sheets are translated. The system adopts the two piezoelectric ceramics to drive the grating sheets and the beam splitter prisms with different widths for beam combination, the structure is simple, and a low-cost double-frequency four-step phase shift pattern can be realized. The fine grating stripes can improve the measurement precision of three-dimensional reconstruction, and the wide grating stripes can improve the measurement depth of field of three-dimensional reconstruction, thereby improving the application scene of the structured light 3D system.

A projection lens has a substrate made of a transparent material, which has a light entry surface for the light exiting a primary optical element in a headlamp. A light emission surface is opposite the light entry surface. A Fresnel structure is formed on the substrate, which contains numerous coaxial annular steps, each of which has an emission surface and a diffractive surface. The emission surface is that part of the step through which light passes. The diffractive surface is that part of the step that is not configured for light to pass through it. At least one of the diffractive surfaces is curved.

The invention provides a projection lens, which sequentially comprises a first lens with positive focal power from a projection surface to an image source surface along an optical axis, a second lens with negative focal power and a third lens with positive focal power from the projection surface to the image source surface, the surface of the projection side of the second lens is a convex surface, and the surface of the image source side of the second lens is a concave surface; the surface of the projection side of the third lens is a concave surface, and the surface of the image source side of the third lens is a concave surface; the surface of the projection side of the fourth lens is a convex surface, and the surface of the image source side of the fourth lens is a convex surface; the surface of the image source side of the fifth lens is a convex surface; the surface of the projection side of the sixth lens is a convex surface; a prism; a protective glass; a piece of plate glass with changeable positions is arranged between the prism and the protective glass, and the plate glass can be located at a first position or a second position through a switching device. According to the projection lens provided by the invention, clear imaging at two different projection distances is realized through switching of the plate glass, and switching between a close shot and a long shot is completed.

Illumination device (10) for a motor vehicle headlamp for generating a low beam, wherein a vertical extension of the low beam extends along a VV-line from at least 0° down to at least −10° on the VV-line, said illumination device (10) comprises: —an optic body (100) comprising a common light input section (110), a light output section (130) and a shell surface (140) limiting the optic body (100), —a projection lens system (200) configured to project the light-rays in front of the illumination device (10), wherein the projection lens system (200) in combination with the optic body (100) are configured to generate the low beam illuminated by the projection lens system (200), wherein the optic body (100) comprises a first set of optically operative surfaces for guiding light-rays along a first light-ray path (LR1), wherein the first set of operative surfaces comprises a first and second light deflection surface (300a, 300b), and a first light exit surface (300c), wherein the first and second light deflection surfaces (300a, 300b) are arranged on the shell surface (140), and wherein the first light exit surface (300c) is arranged on the light output section (130), wherein light rays following the first light-ray path (LR1) are incident on the first deflection surface (300a) and are deflected to the second deflection surface (300b), and wherein light-rays incident on the second deflection surface (300b) are deflected to the first light exit surface (300c), and wherein light-rays emitted by the first light exit surface (300c) contribute to generate a first part of the low beam, and wherein the optic body (100) comprises a second set of optically operative surfaces for guiding light-rays along a second and a third light-ray path (LR2, LR3), wherein the second set of optically operative surfaces comprises a third deflection surface (400a) and a second light exit surface (400b), wherein the third deflection surface (400a) is arranged on the shell surface (140) and the second light exit surface (400b) is arranged on the light output section (130) separate from the first light exit surface (300c), wherein light-rays following the second light-ray path (LR2) are incident on the third deflection surface (400a) and are deflected to the second light exit surface (400b) for coupling out of the optic body (100), and wherein light rays following the third light-ray path (LR3) are incident on the second light exit surface (400b) directly from the common light input section (110), wherein light-rays emitted by the second light exit surface (400b) contribute to generate a second part of the low beam.

The invention discloses a projection lens and a projection illumination system. The projection lens comprises a first lens, a second lens, a third lens and a fourth lens which are coaxially arranged in sequence from an image side to an object side, the diopter of the first lens is negative, the diopter of the second lens is negative, the diopter of the third lens is positive, and the diopter of the fourth lens is positive. By limiting the ratio of the focal length of an optical system to TTL * F.NO, the projection lens can be ensured to have the characteristic of large aperture, the size of the lens is effectively reduced, the ultrathin characteristic and miniaturization of projection are realized, the total length of the projection lens along the optical axis direction is reduced to be less than 23mm, the size of the projection lens is reduced, and the size of the projection lens is reduced. Therefore, the lamp is more suitable for the welcome lamp of the vehicle.

A micro-projection system based on a hybrid refractive-diffractive lens, relating to the technical field of near-eye display devices. A micro-projection lens set sequentially comprises, along an optical axis and from an exit pupil side (6) to an image source side (7), a first lens (1), a second lens (2), a third lens (3), and a fourth lens (4), wherein the first lens (1) is a plano-convex lens and protrudes toward the exit pupil side (6), the second lens (2) is a biconcave lens, the third lens (3) is a meniscus convex lens and protrudes towards the exit pupil side (6), and the fourth lens (4) is a biconvex lens. The first lens (1) has positive focal power, and is used for deflecting large-angle light rays. The second lens (2), the third lens (3), and the fourth lens (4) are cemented by means of an optical adhesive to form a hybrid refractive-diffractive lens; and the cemented surfaces of the second lens (2), the third lens (3), and the fourth lens (4) are each a superposition of an even asphere and a diffractive surface.

The invention provides a long-exit-pupil-distance broadband common-aperture composite simulation optical system, and belongs to the technical field of target scene composite analog simulation. A broadband objective lens group A, a space beam combiner group B and a long-wave infrared projection lens group D are sequentially arranged in the optical system from left to right along light, a visible light projection lens group C is located on the upper side of the space beam combiner group B, and a long-wave infrared projection lens group C is located on the lower side of the space beam combiner group B; a visible light image plane is positioned on the right side of the visible light projection lens group C; the medium-wave infrared projection lens group E is located on the lower side of the space beam combiner lens group B, the medium-wave infrared image surface is located on the lower side of the medium-wave infrared projection lens group E, the long-wave infrared image surface is located on the right side of the medium-wave infrared image surface, and the exit pupil position is located on the left side of the broadband objective lens group A; the problem that a single-channel target modulo system only adapts to simulation of imaging guidance equipment of a specific wave band and is not suitable for semi-physical simulation tests of three-mode composite imaging guidance equipment and two-mode composite imaging guidance equipment is solved.

A low-beam headlight includes a light source arrangement for generating a light cone consisting of light that is less divergent in a first transverse direction than in a second transverse direction perpendicular to the first transverse direction. The low-beam headlight includes beamforming optics for generating, on the basis of light, a light / dark distribution comprising a light / dark edge extending obliquely at least in portions with respect to the first transverse direction and the second transverse direction, wherein the beamforming optics comprises a condenser lens array for receiving incident light, and a projection lens array with a multitude of projection lenses for outputting light received by the condenser lens array. Compared to a second projection lens assigned to a second condenser lens of the first column, a first projection lens assigned to a first condenser lens of the first column of the matrix is decentered differently with respect to the assigned condenser lens along the second transverse direction.

The invention discloses a reflector structure for a projection imaging lens, which comprises a reflector body, the reflector body is placed in an optical projection imaging lens with more than two lenses, and the reflector body comprises a middle light-passing area, a middle light-passing area and a middle light-passing area, so that light of the optical projection imaging lens is emitted through the middle light-passing area to become direct emergent light; the upper end of the first reflecting region is small and the lower end is large; the upper end of the second reflecting region is large and the lower end is small; the optical projection imaging lens is vertically placed, the light source or the image source is arranged below the optical projection imaging lens, and the lens is arranged above the optical projection imaging lens; the reflector body is configured to be matched with a circular projection imaging lens in rotational symmetry or a projection imaging lens in a non-rotational symmetry structure. The surface brightness and uniformity of the light-emitting surface of the projection lens are improved.

The invention provides a projection lens, which sequentially comprises a first lens with positive focal power from a projection surface to an image source surface along an optical axis, a second lens with negative focal power and a third lens with positive focal power from the projection surface to the image source surface, the surface of the projection side of the second lens is a convex surface, and the surface of the image source side of the second lens is a concave surface; the surface of the projection side of the third lens is a concave surface, and the surface of the image source side of the third lens is a convex surface; the surface of the projection side of the fourth lens is a concave surface; the surface of the projection side of the fifth lens is a concave surface, and the surface of the image source side of the fifth lens is a convex surface; the surface of the projection side of the sixth lens is a convex surface, and the surface of the image source side of the sixth lens is a convex surface; a prism; a protective glass; plate glass is arranged between the prism and the protective glass, and the plate glass can be located at a first position or a second position through a switching device. According to the projection lens provided by the invention, clear imaging at two different projection distances is realized through switching of the plate glass, and switching between a close shot and a long shot is completed.

The embodiment of the invention provides a projection lens module and micro projection equipment. The projection lens module sequentially comprises a first lens group, a diaphragm and a second lens group from an object side to an image side along an optical axis; the first lens group comprises a first doublet lens and a third lens which are arranged along the optical axis, the first doublet lens has positive focal power, the third lens has negative focal power, and the first doublet lens can move along the optical axis to adjust the focal length of the projection lens module; the second lens group comprises a second doublet lens, a third doublet lens and an eighth lens which are sequentially arranged along the optical axis, the second doublet lens, the third doublet lens and the eighth lens all have positive focal power, the third doublet lens can move along the optical axis, and the eighth lens can move along the optical axis. The third lens is used for compensating image plane displacement caused by movement of the third lens so as to keep clear imaging; the diaphragm is located between the third lens and the second doublet lens.

A wide angle zoom projection lens, which from the magnifying side to the narrowing side of the lens sequentially comprising: a first lens group with negative diopter, a second lens group, a third lens group with positive diopter, a fourth lens group with positive diopter, a fifth lens group with positive diopter, a sixth lens group with positive diopter, and an aperture in the lens; during the zooming, the first lens group and the sixth lens group are fixed, the second to fifth lens groups move along the optical axis to achieve changes in focal length; The front lens of the first lens group closest to the magnifying side of the lens is an aspherical lens with negative diopter to achieve a wide angle effect.

The invention provides a projection lens, which comprises seven lenses from a projection surface to an image source surface along an optical axis: a first lens with negative focal power; the surface of the projection side of the second lens is a convex surface, and the surface of the image source side of the second lens is a convex surface; the surface of the image source side of the third lens is a convex surface; the surface of the projection side of the fourth lens is a concave surface, and the surface of the image source side of the fourth lens is a convex surface; the surface of the image source side of the fifth lens is a concave surface; the surface of the projection side of the sixth lens is a convex surface, and the surface of the image source side of the sixth lens is a convex surface; and the surface of the projection side of the seventh lens is a convex surface. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

PURPOSE: To relate to a multi-beam image generating device and a multi-beam image generating method that rapidly acquire images by generating multiple primary electron beams while maintaining a sample in a horizontal position, irradiating the sample with these beams while moving the sample, separating the multiple secondary electron beams with a beam splitter, detecting information on respective images with an electron detection device to synthesize a single image.CONSTITUTION: A multi-beam image generating device includes a multiple beam generating device, a beam splitter, an objective lens, a deflection system, a projection lens, a stage, and height measuring means, and is configured to make multiple primary electron beams incident on the axis of the objective lens via the beam splitter while the stage is maintained horizontal on the basis of the sample height output from the height measuring means, radiate the finely focused primary electron beam and scan with the deflection system, make secondary electrons emitted from the sample incident on the axis of the projection lens via the beam splitter, and form images to output image information of the multiple electron beams.SELECTED DRAWING: Figure 19

A head-mounted display device employs controllable aperture projection for uniformity of a waveguide display within a field of view and eyebox domain. A waveguide-based display to control pupil replication density may comprise an image panel to provide light, a projection lens to receive and focus the light from the image panel, a variable aperture to pass the focused light in a controllable manner, and a waveguide to project the focused light passed through by the variable aperture onto an eye box, wherein the variable aperture is positioned at an entrance of the waveguide.

The invention relates to the technical field of optics, in particular to a projection lens, a projection system and electronic equipment. The projection lens comprises a first lens group, an aperture diaphragm and a second lens group which are sequentially arranged from a projection surface to an image source surface along an optical axis, the first lens group has negative focal power, and the second lens group has positive focal power; the first lens group consists of a first lens, a first sub-lens group and a diaphragm front lens which are sequentially arranged from a projection surface to an image source surface along an optical axis; the first sub-lens group comprises at least one lens with negative focal power; the first lens and the diaphragm front lens respectively have positive focal power, and the first sub-lens group has negative focal power; the second lens group consists of a diaphragm rear lens and a second sub-lens group which are sequentially arranged from the projection surface to the image source surface along the optical axis; the second sub-lens group has positive focal power and comprises a group of balsaming lenses with positive focal power, and the diaphragm rear lens has negative focal power. The focusing range of the projection lens is larger than or equal to 500 mm.

The invention provides a projection system and optical display equipment. The projection system comprises a projection lens, a color combination prism and an image source, the projection lens comprises a first lens, a second lens, a third lens and a fourth lens, and the curvature of the lenses and the focal length of the projection lens meet the following conditions:-0.1 < (K1 + K2) / f < 0.1, 0.2 < (K3 + K4) / f < 0.35,-0.1 < (K5 + K6) / f < 0 and-0.3 < (K7 + K8) / f <-0.1; k1 and K2 are respectively the curvature of the surface, far away from the image source, of the first lens and the curvature of the surface, close to the image source, of the first lens; k3 and K4 are respectively the curvature of the surface, far away from the image source, of the second lens and the curvature of the surface, close to the image source, of the second lens; k5 and K6 are respectively the curvature of the surface, far away from the image source, of the third lens and the curvature of the surface, close to the image source, of the third lens; k7 and K8 are the curvature of the surface, far away from the image source, of the fourth lens and the curvature of the surface, close to the image source, of the fourth lens respectively; f is the focal length of the projection lens.

A lighting module is provided for generating two different lighting effects, and includes at least one light source, a first primary optical element, a second primary optical element, and a projection lens. The first primary optical element contains a diffusion surface diffusing the light beams from the light source to homogenously light the projections lens for a first lighting effect. The first primary optical element has a first reflector and second reflector. The first reflector reflects light beams from the light source in a boundary area between the diffusion surface and another section of the lighting module onto the second reflector to direct these light beams through the diffusion surface onto the projection lens. The second primary optical element directs light beams from the light source onto the projection lens to light the projection lens for a second lighting effect.

The invention provides a projection lens, which comprises seven lenses in total, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from a projection surface to an image source surface along an optical axis, the second lens has positive focal power; the surface of the image source side of the third lens is a convex surface; the surface of the projection side of the fourth lens is a concave surface, and the surface of the image source side of the fourth lens is a convex surface; the surface of the image source side of the fifth lens is a concave surface; the surface of the projection side of the sixth lens is a convex surface, and the surface of the image source side of the sixth lens is a convex surface; the seventh lens has positive focal power; wherein the surface curvature radius R1 of the projection side of the first lens and the surface curvature radius R2 of the image source side of the first lens meet the following formula:-0.8 lt; (R1 + R2) / (R1-R2) lt; and 0.5. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

The invention relates to a small projection lens. Comprising a first lens with positive focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with positive focal power, a fifth lens with positive focal power, a diaphragm, a sixth lens with positive focal power and a seventh lens with negative focal power which are sequentially arranged along the direction of an optical axis, the small projection lens comprises a first lens with positive focal power, an eighth lens with positive focal power, a ninth lens with negative focal power, a tenth lens with positive focal power and an eleventh lens with positive focal power, and the effective focal length and the total length of the small projection lens are reasonably set. The camera lens is small in size, low in cost, small in projection ratio and large in aperture, can be matched with multiple DMD chips, provides enough projection brightness and size, is clear and sharp in projection picture, high in contrast ratio and accurate in color restoration, and meets strict use requirements under vehicle-mounted high and low temperature environment conditions at the same time.

The invention discloses a projection lens and a head-up display system, and the projection lens comprises a plurality of lenses and a diaphragm, and the diaphragm is located at the light-emitting sides of the plurality of lenses, and is used for limiting the light-emitting range of the projection lens, so that the projection lens can be matched with an optical waveguide; by limiting the ratio of the effective focal length f to TTL * F.NO in the projection lens, the projection lens has the characteristic of large aperture, the size of the projection lens is effectively reduced, and the projection lens is ultrathin and miniaturized.

The invention provides a projection lens, which comprises five lenses in total, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from a projection surface to an image source surface along an optical axis, the surface of the projection side of the second lens is a convex surface, and the surface of the image source side of the second lens is a convex surface; the surface of the projection side of the third lens is a concave surface, and the surface of the image source side of the third lens is a concave surface; the surface of the projection side of the fourth lens is a convex surface, and the surface of the image source side of the fourth lens is a convex surface; the surface of the projection side of the fifth lens is a convex surface, and the surface of the image source side of the fifth lens is a convex surface; wherein the real image height IH corresponding to the maximum field angle of the projection lens and the effective focal length f of the projection lens meet the following conditions: 0.6 lt; iH / flt; and 0.8. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

A mirror system comprising an EUV mirror (M1-M6), a temperature sensor (30), a control unit (29), and a temperature control module (26), wherein the EUV mirror (M1-M6) has a mirror body (38) and an optical surface (39) formed on the mirror body (38). The temperature sensor (30) determines a temperature measurement of the mirror body (38) and transmits the temperature measurement to the control unit (29). The control unit (29) evaluates the temperature measurement to determine control commands for the temperature control module (26). The temperature control module (26) is controlled by the control commands, so that the temperature control module (26) influences the temperature of the mirror body. In an initial operating state of the mirror system, the control unit (29) determines the control commands by processing an initial temperature setpoint for the temperature of the mirror body (38).In a second operating state of the mirror system, the control unit (29) determines the control commands by processing a second temperature setpoint for the temperature of the mirror body (38). The invention also relates to a method for operating a mirror system, a projection lens for a microlithographic projection exposure system, and a computer program product.

The invention provides a projection lens, which comprises seven lenses from a projection surface to an image source surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power and a fifth lens with negative focal power, the surface of the projection side of the second lens is a concave surface, and the surface of the image source side of the second lens is a convex surface; the surface of the projection side of the third lens is a convex surface, and the surface of the image source side of the third lens is a concave surface; the surface of the projection side of the fourth lens is a convex surface, and the surface of the image source side of the fourth lens is a concave surface; the surface of the image source side of the fifth lens is a concave surface; the surface of the projection side and the surface of the image source side of the sixth lens are convex surfaces; and the seventh lens has positive focal power, and the image source side surface of the seventh lens is a convex surface. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.