CN214540215U - Anti-telephoto lens, anti-telephoto system and scanning apparatus - Google Patents

Abstract

The application discloses anti-telephoto lens, anti-telephoto system, and scanning apparatus. The anti-telephoto lens sequentially includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an image side along an optical axis; the range of the inverse telephoto ratio of the inverse telephoto lens is [7.40, 7.80 ]. The anti-telephoto lens of the embodiment of the application has a large anti-telephoto ratio, has a strong convergence effect on light beams passing through the anti-telephoto lens, and can remarkably improve the optical power density of laser when a collocated laser is used so as to increase the illumination intensity of the laser under the limited maximum power.

Description

Anti-telephoto lens, anti-telephoto system and scanning apparatus

Technical Field

The present application relates to the field of optical detection, and more particularly, to an anti-telephoto lens, an anti-telephoto system, and a scanning apparatus.

Background

At present, the common technical means for detecting defects of workpieces, such as defects on the surface of a wafer, is an optical detection technology, which has the advantages of high detection speed, no pollution and the like. After the laser is irradiated on the wafer surface, the number of particles existing in the region is judged by scattering light by the particles on the wafer surface. However, since the scattered light intensity is proportional to the 6 th power of the particle diameter, the smaller the size of the target particle, the lower the scattered light intensity of the target particle is exponentially decreased by the 6 th power. When the particle is smaller than a certain size, the system cannot detect the scattered light signal of the particle. Therefore, when detecting small-sized particles, a laser with higher power is required to make the illumination intensity compensate for the decrease in optical signal due to the decrease in particle size. However, since the maximum power of the laser is limited, how to increase the optical power density of the laser to increase the illumination intensity at the limited maximum power is a problem that needs to be solved by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an anti-telephoto lens, an anti-telephoto system and a scanning device.

The anti-telephoto lens according to the embodiment of the present application includes, in order from an object side to an image side along an optical axis, a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element; the dereflection ratio of the dereflection lens is [7.40, 7.80 ].

In some embodiments, the first lens has a negative optical power, the object side surface of the first lens is concave, and the image side surface of the first lens is concave. The second lens has positive focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface. The third lens has negative focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface. The object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface. The fifth lens has positive focal power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface.

In some embodiments, the fifth lens is a glass lens, and a distance between an image side surface of the fifth lens and an image plane is in a range of [155.00mm, 298.00mm ].

In some embodiments, the focal length of the anti-telephoto lens ranges from [20.00mm, 40.00mm ].

In some embodiments, the first to fifth lenses are all cylindrical lenses.

In some embodiments, the inverse telephoto lens further includes a stop disposed between the third lens and the fourth lens.

In some embodiments, the reverse telephoto lens satisfies the conditional expression: -7.70mm ≦ f1 ≦ -6.90mm, where f1 is the focal length of the first lens.

In some embodiments, the reverse telephoto lens satisfies the conditional expression: 44.00mm ≦ f2 ≦ 53.00mm, wherein f2 is the focal length of the second lens.

In some embodiments, the reverse telephoto lens satisfies the conditional expression: f3 is less than or equal to-77.00 mm and is less than or equal to-127.00 mm; wherein f3 is the focal length of the third lens.

In some embodiments, the reverse telephoto lens satisfies the conditional expression: -133.00mm ≦ f4 ≦ 1434.00mm, wherein f4 is a focal length of the fourth lens.

In some embodiments, the reverse telephoto lens satisfies the conditional expression: -61.50mm ≦ f5 ≦ -50.30mm, wherein f5 is a focal length of the fifth lens.

In some embodiments, the first lens has an on-axis distance from an object-side surface to an image-side surface of 3.70 mm.

In some embodiments, the second lens has an on-axis distance from an object-side surface to an image-side surface of 4.38 mm.

In some embodiments, the on-axis distance from the object-side surface to the image-side surface of the third lens is 3.70 mm.

In some embodiments, the on-axis distance from the object-side surface to the image-side surface of the fourth lens is 3.70 mm.

In some embodiments, the fifth lens has an on-axis distance from an object-side surface to an image-side surface of 3.70 mm.

In some embodiments, the on-axis distance from the image-side surface of the first lens to the object-side surface of the second lens is 31.40 mm.

In some embodiments, the on-axis distance from the image-side surface of the second lens to the object-side surface of the third lens is 2.85 mm.

In some embodiments, the on-axis distance from the image-side surface of the third lens to the object-side surface of the fourth lens is 13.45 mm.

In some embodiments, the on-axis distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens is 3.12 mm.

In some embodiments, the on-axis distance from the image-side surface to the imaging surface of the fifth lens is 297.28 mm.

The anti-telephoto system according to an embodiment of the present application includes a light source and the anti-telephoto lens according to any one of the embodiments. The light source is arranged on the object side of the reverse telephoto lens and is used for emitting light towards the object side of the first lens.

The scanning device of the embodiment of the application comprises a detection system and the anti-telephoto system of any one of the above embodiments. The detection system is used for receiving light scattered or reflected by an object.

The anti-telephoto lens of the embodiment of the application has a large anti-telephoto ratio, has a strong convergence effect on light beams passing through the anti-telephoto lens, and can remarkably improve the linear power density of laser when a collocated laser is used so as to increase the illumination intensity of the laser under the limited maximum power.

Additional aspects and advantages of embodiments of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic view of a reverse telephoto lens according to some embodiments of the present application;

FIG. 2 is a schematic diagram of an imaging plane and an image of an imaging plane of a reverse telephoto lens according to some embodiments of the present application;

FIG. 3 is a schematic diagram of an imaging plane and an image of an imaging plane of a reverse telephoto lens according to some embodiments of the present application;

FIG. 4 is a schematic view of a reverse telephoto system according to certain embodiments of the present application;

FIG. 5 is a schematic view of a reverse telephoto system according to certain embodiments of the present application;

FIG. 6 is a schematic diagram of a scanning device according to some embodiments of the present application.

Detailed Description

Embodiments of the present application will be further described below with reference to the accompanying drawings. The same or similar reference numbers in the drawings identify the same or similar elements or elements having the same or similar functionality throughout.

In addition, the embodiments of the present application described below in conjunction with the accompanying drawings are exemplary and are only for the purpose of explaining the embodiments of the present application, and are not to be construed as limiting the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1, the present application provides a reverse telephoto lens 100. The inverse telephoto lens 100 includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. The range of the reverse telephoto ratio of the reverse telephoto lens 100 is [7.40, 7.80], and for example, the range of the reverse telephoto ratio may be any value within [7.40, 7.80], such as 7.40, 7.43, 7.49, 7.50, 7.52, 7.57, 7.60, 7.61, 7.64, 7.68, 7.70, 7.73, 7.75, 7.77, and 7.80.

The reverse telephoto ratio of the reverse telephoto lens 100 is a ratio of a rear working distance of the reverse telephoto lens 100 to a focal length of the reverse telephoto lens 100, and a numerical value of the reverse telephoto ratio is a reverse telephoto value.

The anti-telephoto lens 100 of the embodiment of the application has a large anti-telephoto ratio, has a strong converging effect on light beams passing through the anti-telephoto lens, and can significantly improve the optical power density of laser when a laser is matched for use so as to increase the illumination intensity of the laser under the limited maximum power.

The following detailed description is made with reference to the accompanying drawings.

Referring to fig. 1, the anti-telephoto lens 100 according to the embodiment of the present disclosure includes, in order from an object side to an image side along an optical axis, a first lens L1 having negative power, a second lens L2 having positive power, a third lens L3 having negative power, a fourth lens L4, and a fifth lens L5 having positive power. The fourth lens L4 may be a lens with positive power, or may be a lens with negative power, which is not limited herein.

The first lens L1 has an object-side surface S1 and an image-side surface S2, the object-side surface S1 of the first lens L1 is concave, and the image-side surface S2 of the first lens L1 is concave. The second lens L2 has an object-side surface S3 and an image-side surface S4, the object-side surface S3 of the second lens L2 is concave, and the image-side surface S4 of the second lens L2 is convex. The third lens element L3 has an object-side surface S5 and an image-side surface S6, wherein the object-side surface S5 of the third lens element L3 is convex, and the image-side surface S6 of the third lens element L3 is concave. The fourth lens element L4 has an object-side surface S7 and an image-side surface S8, wherein the object-side surface S7 of the fourth lens element L4 is convex, and the image-side surface S8 of the fourth lens element L4 is concave. The fifth lens element L5 has an object-side surface S9 and an image-side surface S10, wherein the object-side surface S9 of the fifth lens element L5 is convex, and the image-side surface S10 of the fifth lens element L5 is convex.

A light flux entering from the object side surface S1 of the first lens L1, passing through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 in this order, and exiting from the image side surface S10 of the fifth lens L5 can be converged on the image forming surface S11. If the light beam is laser emitted by the laser at a rated power, the laser sequentially passing through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 in the anti-telephoto lens 100 is converged on the imaging surface S11 on the premise of not increasing the rated power of the laser, so that the irradiation range of the laser with the same energy in unit time on the imaging surface S11 is more concentrated, and the power density of the laser is improved. Through improving the power density of laser, can realize the effect of increase laser intensity to the light intensity of the reverberation that the object reflected when making laser detection object increases, can be detected by check out test set, thereby realizes the detection to the less object of size.

In some embodiments, the first lens L1 to the fifth lens L5 of the anti-telephoto lens 100 are all plastic lenses, which are light in weight, easy to produce, and low in cost.

In the embodiment of the present application, the first lens L1 to the fifth lens L5 of the anti-telephoto lens 100 are all glass lenses. The glass has high temperature resistance, high light transmittance, high refractive index, high humidity resistance and stable material. In addition, the glass lens has stable physical properties, the surface shape, the size and the refractive index of the glass lens are not easy to change along with the rise of temperature, and the imaging quality is better.

Referring to fig. 1 and 2, in some embodiments, the first lens L1 to the fifth lens L5 of the anti-telephoto lens 100 are all spherical mirrors. The anti-telephoto lens 100 in which the first lens L1 to the fifth lens L5 are all spherical mirrors can converge light beams in any dimension direction. For example, the imaging plane S11 includes a first direction X and a second direction Y perpendicular to each other, the light beam passing through the anti-telephoto lens 100 can be narrowed down in any direction in the X-Y plane, and the size of the narrowed light beam in each direction of the image I1 of the imaging plane S11 is reduced compared to the image I0 of the light beam in the imaging plane S11 before being narrowed down, i.e., the light beam is converged in each direction. If the light beam is laser emitted by the laser at rated power, the irradiation ranges of the laser with the same energy in each direction on the imaging surface S11 can be more concentrated, so that the power density of the laser is improved, the effect of increasing the light intensity can be realized, and the device can be used for detecting objects with smaller sizes.

Referring to fig. 1 and 3, in the embodiment of the present application, the first lens L1 to the fifth lens L5 of the anti-telephoto lens 100 are cylindrical mirrors. The anti-telephoto lens 100 in which the first lens L1 to the fifth lens L5 are cylindrical lenses is capable of converging light beams in a single dimensional direction. For example, the image forming surface S11 includes a first direction X and a second direction Y perpendicular to each other, and the light beam passing through the reverse telephoto lens 100 can be narrowed down in the first direction X or narrowed down in the second direction Y. Compared with the imaging I2 of the light beam on the imaging surface S11 before being narrowed, the imaging I3 of the light beam on the imaging surface S11 after being narrowed is reduced in size only in the first direction X or the second direction Y, that is, the light beam is converged only in the first direction X or only in the second direction Y.

Referring to fig. 4 and 5, if the light beam is a laser beam emitted by a laser at a rated power, the irradiation range of the laser beam with the same energy per unit time on the imaging surface S11 in only one dimension direction is more concentrated (as shown in fig. 4), and the irradiation range in the other dimension direction can still be kept larger (as shown in fig. 5). When the laser is used for line scanning, the laser can have a larger irradiation range in a dimension direction (as shown in fig. 5) perpendicular to the line scanning direction so as to have a larger scanning range, so as to enlarge a scanning area in a unit time at the same scanning speed and improve the scanning efficiency; meanwhile, the laser can be narrowed in the dimension direction (as shown in fig. 4) along the line scanning direction, so that the irradiation range of the laser with the same energy in unit time in the dimension direction along the line scanning direction is more concentrated, the power density of the laser is improved, and the effect of increasing the light intensity can be realized. Thus, the anti-telephoto lens 100 with the first lens L1 to the fifth lens L5 being cylindrical lenses can narrow laser in only one dimension direction when used in combination with a laser, so that the laser used for line scanning can improve the optical power density while keeping a certain scanning range and a certain scanning efficiency, so as to improve the light intensity of the laser, and meet the requirement on the light intensity during light detection.

Referring to fig. 1, in some embodiments, the fifth lens element L5 is a glass lens element, and a distance between the image-side surface S10 of the fifth lens element L5 and the image-forming surface S11 is [155.00mm, 298.00mm ], for example, a distance between the image-side surface S10 of the fifth lens element L5 and the image-forming surface S11 is 155.00mm, 155.02mm, 155.39mm, 161.17mm, 173.36mm, 182.57mm, 194.69mm, 200.07mm, 213.34mm, 228.98mm, 230.00mm, 247.15mm, 256.74mm, 269.07mm, 277.49mm, 285.88mm, 296.00mm, 297.27mm, 297.28mm, 298.00mm, and the like, which are not limited herein.

The distance between the image-side surface S10 of the fifth lens L5 and the image plane S11 is the rear working distance of the reverse telephoto lens 100. If the rear working distance of the anti-telephoto lens 100 is less than 155.00mm, it is difficult to arrange optical instruments used in cooperation with the anti-telephoto lens 100, the arrangement space margin is small, it is difficult to select optical instruments (such as an optical machine) of a proper type to be used in cooperation with the anti-telephoto lens 100, and when the anti-telephoto lens 100 is used in cooperation with the optical instruments for scanning, the scanning distance may be small, and the scanning requirement is difficult to meet. If the rear working distance of the anti-telephoto lens 100 is greater than 298.00mm, the focal length of the anti-telephoto lens 100 is required to be high, and it becomes difficult to design the lens of the anti-telephoto lens 100.

In the embodiment of the application, the value range of the distance between the image side surface S10 of the fifth lens L5 and the image plane S11 is [155.00mm, 298.00mm ], it can be satisfied that the rear working distance of the anti-telephoto lens 100 is suitable, it is not difficult to arrange and select optical instruments used in a matched manner due to too small rear working distance of the anti-telephoto lens 100, and it is not difficult to design lenses meeting requirements due to too large rear working distance of the anti-telephoto lens 100, and the anti-telephoto lens 100 can have a certain scanning distance when scanning with the optical instruments, so as to satisfy the scanning requirements.

In some embodiments, the focal length of the retrotelephoto lens 100 is in a range of [20.00mm, 40.00mm ], for example, the focal length of the retrotelephoto lens 100 is 20.00mm, 21.02mm, 22.39mm, 23.17mm, 24.36mm, 25.57mm, 26.69mm, 27.07mm, 28.34mm, 29.98mm, 30.00mm, 31.15mm, 32.74mm, 33.07mm, 34.49mm, 35.88mm, 36.00mm, 37.27mm, 38.28mm, 39.75mm, 40.00mm, etc., which are not listed herein.

If the focal length of the anti-telephoto lens 100 is less than 20.00mm, the rear working distance may be insufficient, which makes the arrangement and type selection of the optical instrument used in conjunction with the anti-telephoto lens 100 difficult. If the focal length of the anti-telephoto lens 100 is greater than 40.00mm, the convergence degree of the light beam imaged on the imaging surface S11 by the anti-telephoto lens 100 may be insufficient, the narrowing width of the image formed on the light beam imaging surface S11 may be small, and the increase width of the power density of the laser beam may not be large when the light beam is a laser beam.

In the embodiment of the application, the range of the focal length of the anti-telephoto lens 100 is [20.00mm, 40.00mm ], which can satisfy the requirement that the focal length of the anti-telephoto lens 100 is suitable, which neither leads to the difficulty in arranging and selecting optical instruments used by the anti-telephoto lens 100 due to the too small focal length of the anti-telephoto lens 100, nor leads to the insufficient convergence degree of the light beam imaged on the imaging surface S11 through the anti-telephoto lens 100 due to the too large focal length of the anti-telephoto lens 100, so that when the light beam imaged on the imaging surface S11 through the anti-telephoto lens 100 is laser, the laser can be compressed to narrow by a certain extent to significantly improve the power density of the laser.

Further, the rear working distance of the anti-telephoto lens 100 has a value range of [155.00mm, 298.00mm ], and the focal length of the anti-telephoto lens 100 has a value range of [20.00mm, 40.00mm ], and the value range of the anti-telephoto ratio of the anti-telephoto lens 100 can reach [7.40, 7.80] by selecting an appropriate rear working distance of the anti-telephoto lens 100 and an appropriate focal length of the anti-telephoto lens 100 within the above ranges. Thus, the anti-telephoto lens 100 can have a proper focal length while ensuring a proper rear working distance, so as to facilitate arrangement and type selection of optical instruments used in cooperation with the anti-telephoto lens 100, and meet a convergence requirement for a light beam imaged on the imaging surface S11 by the anti-telephoto lens 100, so that the light beam can be narrowed as desired; when the light beam is laser, the laser can be narrowed by a certain amplitude so as to remarkably improve the power density of the laser; when the light beam is used for scanning, a certain scanning distance can be provided so as to meet the scanning requirement.

Referring to fig. 1, in some embodiments, the inverse telephoto lens 100 satisfies the following conditional expression:

-7.70mm≤f1≤-6.90mm：

where f1 is the focal length of the first lens L1.

That is, the focal length of the first lens L1 can be any value within the range of [ -7.70mm, -6.90mm ], for example, the focal length of the first lens L1 can be-7.70 mm, -7.63mm, -7.54mm, -7.41mm, -7.35mm, -7.27mm, -7.12mm, -7.00mm, -6.98mm, -6.90mm, etc., which are not listed herein.

In some embodiments, the reverse telephoto lens 100 satisfies the conditional expression:

44.00mm≤f2≤53.00mm：

wherein f2 is the focal length of the second lens L2.

That is, the focal length of the second lens L2 may have any value in the range of [44.00mm, 53.00mm ], for example, the focal length of the second lens L2 may be 44.00mm, 45.20mm, 46.61mm, 47.38mm, 48.52mm, 49.87mm, 50.00mm, 51.28mm, 52.98mm, 53.00mm, etc., which are not listed here.

In some embodiments, the reverse telephoto lens 100 satisfies the conditional expression:

-127.00mm≤f3≤-77.00mm：

where f3 is the focal length of the third lens L3.

That is, the focal length of the third lens L3 can be any value within the range of [ -127.00mm, -77.00mm ], for example, the focal length of the third lens L3 can be-127.00 mm, -121.63mm, -113.54mm, -108.41mm, -104.35mm, -95.27mm, -90.12mm, -86.00mm, -80.98mm, -77.00mm, etc., which are not listed here.

In some embodiments, the reverse telephoto lens 100 satisfies the conditional expression:

-133.00mm≤f4≤1434.00mm；

where f4 is the focal length of the fourth lens L4.

That is, the focal length of the fourth lens L4 may be any value within the range of [ -133.00mm, 1434.00mm ], for example, the focal length of the fourth lens L4 may be-133.00 mm, -100.63mm, -51.54mm, -23.41mm, -7.35mm, 15.27mm, 160.12mm, 270.00mm, 355.98mm, 486.00mm, 521.34mm, 679.20mm, 717.61mm, 852.38mm, 971.52mm, 1000.00mm, 1165.04mm, 1279.28mm, 1386.98mm, 1434.00mm, etc., which are not listed herein.

In some embodiments, the reverse telephoto lens 100 satisfies the conditional expression:

-61.50mm≤f5≤-50.30mm；

where f5 is the focal length of the fifth lens L5.

That is, the focal length of the fifth lens L5 can be any value within the range of [ -61.50mm, -50.30mm ], for example, the focal length of the first lens L1 can be-61.50 mm, -60.63mm, -59.54mm, -58.41mm, -57.35mm, -56.27mm, -55.12mm, -54.00mm, -53.98mm, -52.74mm, -51.08mm, -50.30mm, etc., which are not listed herein.

In summary, the first lens L1 to the fifth lens L5 of the anti-telephoto lens 100 satisfy the above conditional expressions, and the focal length of the anti-telephoto lens 100 can be set to a range of [20mm, 40mm ], so that the focal length of the anti-telephoto lens 100 is appropriate to have sufficient convergence power, and the appropriate rear working distance of the anti-telephoto lens 100 can be set according to the focal length of the anti-telephoto lens 100.

Referring to fig. 1, in some embodiments, the anti-telephoto lens 100 satisfies one or more of the following conditions:

the on-axis distance from the object side surface S1 to the image side surface S2 of the first lens L1 is 3.70 mm;

the on-axis distance from the object side surface S3 to the image side surface S4 of the second lens L2 is 4.38 mm;

the on-axis distance from the object-side surface S5 to the image-side surface S6 of the third lens L3 is 3.70 mm;

the on-axis distance from the object side surface S7 to the image side surface S8 of the fourth lens L4 is 3.70 mm; and

the on-axis distance from the object-side surface S9 to the image-side surface S10 of the fifth lens L5 is 3.70mm,

for example, the anti-telephoto lens 100 may satisfy only that the on-axis distance from the object side surface S7 to the image side surface S8 of the fourth lens L4 is 3.70 mm; alternatively, the anti-telephoto lens 100 may satisfy that an on-axis distance from the object-side surface S1 to the image-side surface S2 of the first lens L1 is 3.70mm and an on-axis distance from the object-side surface S3 to the image-side surface S4 of the second lens L2 is 4.38mm, which is not listed here.

The on-axis distance from the object side to the image side of the lens can characterize to some extent the optical path travelled by the beam within the lens. The larger the distance from the object side surface to the image side surface of the lens on the axis is, the more the optical path of the light beam in the lens is, and the more the light beam is affected by the deflection of the lens; the smaller the on-axis distance from the object side surface to the image side surface of the lens, the smaller the optical path length of the light beam passing through the lens, and the smaller the influence of the deflection of the lens.

In the embodiment of the present application, the inverse telephoto lens 100 may simultaneously satisfy that the on-axis distance from the object side surface S1 to the image side surface S2 of the first lens L1 is 3.70 mm; the on-axis distance from the object side surface S3 to the image side surface S4 of the second lens L2 is 4.38 mm; the on-axis distance from the object-side surface S5 to the image-side surface S6 of the third lens L3 is 3.70 mm; the on-axis distance from the object side surface S7 to the image side surface S8 of the fourth lens L4 is 3.70 mm; and the axial distance from the object-side surface S9 to the image-side surface S10 of the fifth lens L5 is 3.70mm, the axial distance from the object-side surface to the image-side surface of each lens in the anti-telephoto lens 100 is made appropriate so as to ensure an appropriate degree of deflection of the light beam incident from the object side and exiting from the image side of the anti-telephoto lens 100, and the requirement for converging the light beam can be satisfied so that the range of the anti-telephoto value of the anti-telephoto lens 100 can be [7.40, 7.80 ].

Referring to fig. 1, in some embodiments, the anti-telephoto lens 100 satisfies one or more of the following conditions:

the on-axis distance from the image-side surface S2 of the first lens L1 to the object-side surface S3 of the second lens L2 is 31.40 mm;

the on-axis distance from the image-side surface S4 of the second lens L2 to the object-side surface S5 of the third lens L3 is 2.85 mm;

the on-axis distance from the image-side surface S6 of the third lens L3 to the object-side surface S7 of the fourth lens L4 is 13.45 mm;

an on-axis distance from the image-side surface S8 of the fourth lens L4 to the object-side surface S9 of the fifth lens L5 is 3.12 mm; and

the on-axis distance from the image-side surface S10 to the image plane S11 of the fifth lens L5 is 297.28mm,

for example, the anti-telephoto lens 100 may only satisfy that the on-axis distance from the image-side surface S4 of the second lens L2 to the object-side surface S5 of the third lens L3 is 2.85 mm; alternatively, the anti-telephoto lens 100 may satisfy that the on-axis distance from the image-side surface S6 of the third lens L3 to the object-side surface S7 of the fourth lens L4 is 13.45mm, and the on-axis distance from the image-side surface S8 of the fourth lens L4 to the object-side surface S9 of the fifth lens L5 is 3.12mm, which is not listed here.

The on-axis distance from the image side surface of the lens to the object side surface of the lens adjacent to the image side surface is the spacing distance between two adjacent lenses. The separation distance between two adjacent lenses affects not only the degree of deflection of the light beam passing through the lenses but also the rear working distance of the anti-telephoto lens 100, that is, the on-axis distance from the image-side surface S10 of the fifth lens L5 to the image-forming surface S11 in the anti-telephoto lens 100 of the present application.

In the embodiment of the present application, the on-axis distance from the image-side surface S2 of the first lens L1 to the object-side surface S3 of the second lens L2 can be simultaneously satisfied by the anti-telephoto lens 100 by setting the pitches of the five lenses of the first lens L1 to the fifth lens L5 to 31.40 mm; the on-axis distance from the image-side surface S4 of the second lens L2 to the object-side surface S5 of the third lens L3 is 2.85 mm; the on-axis distance from the image-side surface S6 of the third lens L3 to the object-side surface S7 of the fourth lens L4 is 13.45 mm; and the axial distance from the image side surface S8 of the fourth lens L4 to the object side surface S9 of the fifth lens L5 is 3.12mm, so that the axial distance from the image side surface S10 of the fifth lens L5 to the image plane S11 can reach 297.28mm, and the anti-telephoto lens 100 can have a large rear working distance.

Referring to fig. 1, in some embodiments, the anti-telephoto lens 100 may further include a STOP disposed between the third lens L3 and the fourth lens L4. For example, if the axial distance from the image-side surface S6 of the third lens L3 to the object-side surface S7 of the fourth lens L4 is 13.45mm, the STOP may be disposed at a distance (0.00mm, 13.45mm) from the image-side surface S6 of the third lens L3, for example, the STOP may be disposed at a distance of 1.00mm, 2.57mm, 3.98mm, 4.07mm, 5.98mm, 6.44mm, 7.91mm, 8.41mm, 9.07mm, 10.00mm, 11.12mm, 12.35mm, 13.40mm from the image-side surface S6 of the third lens L3, which is not listed here.

Referring to fig. 1 in conjunction with table 1, in one embodiment, the reverse telephoto lens 100 satisfies the conditions of table 1:

TABLE 1

In the reverse telephoto lens 100 shown in table 1, the rear working distance of the reverse telephoto lens 100 is 297.28mm, and the focal length of the reverse telephoto lens 100 is 40.00 mm. The reverse telephoto ratio of the reverse telephoto lens 100 is a ratio of a rear working distance of the reverse telephoto lens 100 to a focal length of the reverse telephoto lens 100, that is, a reverse telephoto value of the reverse telephoto lens 100 is: 297.28mm/40.00mm 7.432. The reverse telephoto lens 100 shown in table 1 has a significantly improved reverse telephoto value compared to the conventional reverse telephoto lens 100 having a reverse telephoto value range of [1.09, 1378 ].

Referring to fig. 4 and 5, the present application provides an anti-telephoto system 1000. The anti-telephoto system 100 includes a light source 200 and the anti-telephoto lens 100 in any of the above embodiments. The light source 200 is disposed on the object side of the reverse telephoto lens 100 and is configured to emit light toward the object side of the first lens L1.

In some embodiments, the reverse telephoto system 1000 may further include an adjustment mirror 500. The adjustment mirror 500 is used to adjust the length of the light spot on the imaging surface S11. For example, referring to fig. 3, the spot I3 is formed on the imaging surface S11 shown in fig. 3, and the spot I3 can be regarded as a spot parallel to the first direction X. The adjustment mirror 500 is used to adjust the length of the spot I3 in the first direction X on the imaging surface S11. When the spot I3 is used to move in the second direction Y to scan an object, the length of the spot I3 in the first direction X can be adjusted by the adjustment mirror 500, for example, the spot I3 is elongated or shortened in the first direction X to adjust the scanning width of the spot I3. The wider the scanning width of the spot I3, the larger the scanning area of the spot I3 that moves at the same rate in the second direction Y, the higher the scanning efficiency; the narrower the scanning width of the light spot I3 is, the higher the convergence degree of the light spot I3 is, and the stronger the scanning light intensity is, and the length of the light spot I3 along the first direction X can be properly adjusted by the adjusting mirror 500 according to requirements to obtain the required scanning width of the light spot I3.

In some embodiments, the light source 200 may be a Laser, for example, the light source 200 may be a Vertical-Cavity Surface-Emitting Laser (VCSEL), a Distributed Feedback Laser (DFB), any combination of a VCSEL and a DFB, or other types of lasers, which is not limited herein. In the reverse telephoto system 1000, the light source 200 can emit laser light through the reverse telephoto lens 100 toward the object located on the imaging plane S11 to converge the laser light on the object, and can be used for laser processing, laser detection, and the like of the object. For example, the lenses in the anti-telephoto lens 100 are all cylindrical lenses, and the laser light emitted by the light source 200 is emitted from the fifth lens L5 of the anti-telephoto lens 100 and then converged on the object in a long strip shape (as shown in fig. 3) for performing line scanning on the object; for another example, all the lenses in the anti-telephoto lens 100 are spherical mirrors, the light source 200 emits light from the first lens L1 of the anti-telephoto lens 100, and the laser light emitted from the fifth lens L5 is focused on the object in a point shape (as shown in fig. 2) for laser processing of the object.

The conventional anti-telephoto lens has a small anti-telephoto value, the range of the anti-telephoto value is [1.09, 1.78], and when the conventional anti-telephoto lens is used in optical detection with a laser, the effect of remarkably improving the linear power density of the laser is difficult to obtain, so that objects with small sizes, such as tiny particles on a wafer, are difficult to detect. In addition, the number of lenses of the existing anti-telephoto lens is large, generally 6 to 13 lenses or even more, so that the light transmittance is reduced, and the cost and the assembly difficulty are increased.

The range of the reverse telephoto value of the reverse telephoto lens 100 in the reverse telephoto system 1000 provided by the present application can reach [7.40, 7.80], so that the reverse telephoto lens 100 can have a large rear working distance, and the light emitted by the light source 200 can be converged on an imaging surface S11 far away from the light source 200, so as to implement functions of illumination, detection, processing and the like of the light emitted by the light source 200; meanwhile, the anti-telephoto lens 100 has a strong converging capability on the light emitted by the light source 200, so that functions of illumination, detection, processing and the like of the light emitted by the light source 200 can be enhanced. In addition, the number of the lenses of the anti-telephoto lens 100 according to the embodiment of the present application is 5, which is less than the number of the lenses of the conventional anti-telephoto lens 100, so that the transmittance of light can be improved, and the cost and the assembly difficulty can be reduced.

Referring to fig. 6, the present application provides a scanning apparatus 10000. The scanning apparatus 10000 includes the reverse telephoto system 1000 and the detection system 2000 in the above embodiments. The detection system 2000 is used to receive light scattered or reflected by an object. In one example, the detection system 2000 is configured to receive light scattered from an object for dark-field detection of the object under inspection; in another example, the detection system 2000 is used to receive light reflected by an object for bright field detection of the detected object; in yet another example, the detection system 2000 includes a plurality of detection devices at different angles with respect to the image forming surface S11, and the different detection devices can be used for receiving the reflected light and the scattered light at different angles, respectively.

In the scanning device 10000 of the present application, the range of the reverse telephoto ratio of the reverse telephoto lens 100 of the reverse telephoto system 1000 can reach [7.40, 7.80], so that the reverse telephoto lens 100 has a larger working distance, which can facilitate the model selection of the detection system 2000 and the arrangement in the scanning device 10000; meanwhile, the anti-telephoto lens 100 has a strong converging capability, and can improve the light intensity of light emitted by the light source 200 of the anti-telephoto system 1000, so as to meet the scanning requirement of the scanning device 10000.

In one embodiment, the light source 200 of the reverse telephoto system 1000 is a laser, the lenses of the reverse telephoto lens 100 in the reverse telephoto system 1000 are cylindrical mirrors, and the scanning device 10000 is used for detecting defects on the surface of a wafer.

Specifically, the laser emitted by the light source 200 toward the reverse telephoto lens 100 is emitted from the fifth lens L5 of the reverse telephoto lens 100 to form a stripe-shaped light spot (as shown in fig. 3) and irradiate on the surface of the wafer on the image side, and the light spot can be moved on the surface of the wafer along a preset direction to scan the wafer. The detection system 2000 can determine the number of wafer surface particles present in the scan area by detecting scattered light scattered from the wafer surface particles. The scattering light intensity is proportional to the 6 th power of the particle diameter, so that when the size of the particle is reduced, the scattering light intensity scattered by the particle is reduced by a 6 th power index, and if the laser intensity of the scanned particle is insufficient, the detection system 2000 cannot detect the scattering light scattered by the smaller particle, so that the number of the detected particles is lower than the actual number of the particles, and the accuracy of the detection result is reduced.

In the scanning apparatus 10000 of the embodiment of the present application, the range of the reverse telephoto ratio of the reverse telephoto lens 100 of the reverse telephoto system 1000 can reach [7.40, 7.80], and the reverse telephoto lens 100 has a strong converging capability while ensuring that the reverse telephoto lens 100 has a certain rear working distance so as not to affect the arrangement of each device or element in the scanning apparatus 10000, so as to significantly improve the light intensity of the light beam emitted from the reverse telephoto lens 100. If the light beam emitted from the anti-telephoto lens 100 is laser, the power density of the laser can be significantly improved to improve the intensity of the laser, so that the light intensity can meet the requirement when the laser is used for detecting an object with a small size, and the detection result is ensured to have certain accuracy.

In the description herein, reference to the description of the terms "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present application, "a plurality" means at least two, e.g., two, three, unless specifically limited otherwise.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations of the above embodiments may be made by those of ordinary skill in the art within the scope of the present application, which is defined by the claims and their equivalents.

Claims (10)

1. An anti-telephoto lens, which comprises, in order from an object side to an image side along an optical axis, a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element; the dereflection ratio of the dereflection lens is [7.40, 7.80 ].

2. The inverse telephoto lens according to claim 1,

the first lens has negative focal power, the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a concave surface;

the second lens has positive focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface;

the third lens has negative focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface;

the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface; and

the fifth lens has positive focal power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface.

3. The inverse telephoto lens system according to claim 1, wherein the fifth lens element is a glass lens, and a distance from an image side surface of the fifth lens element to an image plane has a value in a range of [155.00mm, 298.00mm ]; and/or the presence of a catalyst in the reaction mixture,

the value range of the focal length of the anti-telephoto lens is [20.00mm, 40.00mm ].

4. The anti-telephoto lens according to claim 1, wherein the first lens to the fifth lens are cylindrical lenses.

5. The inverse telephoto lens according to claim 1, further comprising a diaphragm disposed between the third lens and the fourth lens.

6. The anti-telephoto lens according to claim 1, wherein the anti-telephoto lens satisfies the conditional expression:

-7.70mm ≦ f1 ≦ -6.90mm, where f1 is the focal length of the first lens; and/or

44.00mm < f2 < 53.00mm, wherein f2 is the focal length of the second lens; and/or

F3 is less than or equal to-77.00 mm and is less than or equal to-127.00 mm; wherein f3 is the focal length of the third lens; and/or

-133.00mm ≦ f4 ≦ <1434.00mm, wherein f4 is the focal length of the fourth lens; and/or

-61.50mm ≦ f5 ≦ -50.30mm, wherein f5 is a focal length of the fifth lens.

7. The inverse telephoto lens according to claim 1,

the on-axis distance from the object side surface to the image side surface of the first lens is 3.70 mm; and/or

The on-axis distance from the object side surface to the image side surface of the second lens is 4.38 mm; and/or

The on-axis distance from the object side surface to the image side surface of the third lens is 3.70 mm; and/or

The on-axis distance from the object side surface to the image side surface of the fourth lens is 3.70 mm; and/or

The on-axis distance from the object side surface to the image side surface of the fifth lens is 3.70 mm.

8. The anti-telephoto lens according to claim 1, wherein the anti-telephoto lens satisfies a condition:

the on-axis distance from the image side surface of the first lens to the object side surface of the second lens is 31.40 mm; and/or

The on-axis distance from the image side surface of the second lens to the object side surface of the third lens is 2.85 mm; and/or

The on-axis distance from the image side surface of the third lens to the object side surface of the fourth lens is 13.45 mm; and/or

The on-axis distance from the image side surface of the fourth lens to the object side surface of the fifth lens is 3.12 mm; and/or

And the on-axis distance from the image side surface of the fifth lens to the imaging surface is 297.28 mm.

9. An anti-telephoto system, comprising:

a light source; and

the inverse telephoto lens according to any one of claims 1 to 8, the light source being disposed at an object side of the inverse telephoto lens and configured to emit light toward the object side of the first lens.

10. A scanning device, characterized by comprising:

the anti-telephoto system of claim 9; and

a detection system for receiving light scattered or reflected by an object.

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