Priority Claims and Related Patent Applications

[0001] This application claims the benefit of priority from U.S. Provisional Application Serial No. 61/778,692, filed on March 13, 2013, the entire content of which is incorporated herein by reference in its entirety.

Technical Fields of the Invention

[0001] The invention generally relates to optical designs and configurations for microscopes. More particularly, the invention relates to novel optical designs and configurations that significantly reduce the spatial dimensions of microscopes without sacrificing functionalities and performance.

Background of the Invention

[0002] A microscope is an instrument used to see objects that are too small for the naked eye. Earliest optical microscopes consisted of two lenses and simply produced an enlarger image of the object under inspection. A simple compound microscope, for example, consists of an objective lens and an eye-piece lens. Nowadays, the designs can incorporate a number of different components: multiple lenses, filters, polarizers, beam-splitters, sensors, illumination sources, etc.

[0003] For optical microscopes using visible light, typical magnification can reach up to 1500x with a theoretical resolution limit of around 0.2 micrometers or 200 nanometers. Specialized techniques, such as scanning confocal microscopy, may further improve magnification. The use of shorter wavelength light, such as the ultraviolet (UV), is another way to improve the spatial resolution of an optical microscope. UV light allows the imaging of microscopic features and samples that are invisible to the human eye. Near IR light can also be used to visualize otherwise transparent objects. Furthermore, fluorescence microscopy employs fluorescent emission from samples to highlight microscopic features. In modern biological research, for example, fluorescent probes have been developed to investigate various biological specimens. Different from a conventional trans-illuminated optical microscopy, fluorescence microscopy involves illuminating an object with a narrow set of wavelengths of excitation light, which interacts with fluorophores in the sample and causes them to emit fluorescence light that is imaged and recorded.

[0004] The images from an optical microscope can be captured by cameras. A digital optical microscope uses objective lens to collect light and to project the optically enlarged image onto an image sensor, such as charge-coupled device (CCD) or complementary metal-oxide

semiconductor (CMOS) image sensors. The resulting image can be viewed directly on a computer or video monitor without the need for eyepieces. When an infinity-corrected objective lens is used, a tube lens is needed to re-focus the image. Where large magnification is needed, a projection lens can be added and adjusted between the focal plane and the image sensor.

[0005] The majority of optical microscopes are designed to be a vertically mounted instrument, with an eye piece(s) and/or a camera at the top to facilitate viewing and recording. Such a design is not suited for fitting into a tight space for remote or automated observation with an image sensor. Thus, there remains a need for novel designs and configurations that minimize space requirements of microscopes to allow miniaturization, portability and other special

functionalities.

Summary of the Invention

[0006] The invention is based, in part, on the discovery of unique designs and configurations that substantially reduce the overall size of an optical microscope. The invention enables miniaturized and portable designs of microscopes that minimize space requirements and allow miniaturization, portability and other special functionalities.

[0007] Embodiments of this invention are directed to an optical design of compact microscope systems that can be fit into a small space by strategically rearranging the objective lens set and by folding the optical path between objective lens and image sensor.

[0008] In one aspect, the invention generally relates to a compact microscope. The compact microscope includes (1) an objective lens set comprising a first lens group of two or more lens proximal to the objective end of the objective lens set, (2) a light reflecting component, and (3) a second lens group of lens proximal to the viewing or imaging end of the objective lens set. The light reflecting component is disposed between and in the optical path of the first lens group and the second lens group such that the angle between the incidental beam and the reflective beam is less than about 120°.

[0009] In another aspect, the invention generally relates to a compact objective lens unit suitable for use in an optical microscopic system. The compact objective lens unit includes a first lens group of two or more lens proximal to the objective end of the objective lens set, a light reflecting component, and a second lens group of lens proximal to the viewing or imaging end of the objective lens set. The light reflecting component is disposed between and in the optical path of the first lens group and the second lens group such that the angle between the incidental beam and the reflective beam is less than about 120°.

[0010] In yet another aspect, the invention generally relates to a compact microscope. The compact microscope includes: an objective lens unit that includes a front lens group, a first lens group of two or more lens proximal to the objective end of the objective lens set, a first light reflecting component, and a second lens group of lens proximal to the viewing or imaging end of the objective lens set. The first light reflecting component is disposed between and in the optical path of the first lens group and the second lens group such that the angle between the incidental beam and the reflective beam is less than about 90°. The compact microscope further includes: a second light reflecting component or set; a projection lens set; and an image sensor or a viewing window. The second light reflecting component or set folds the optical path such that the optical path directs the light beam to the imagine sensor or viewing window disposed adjacent the objective lens unit.

Brief Description of the Drawings [0011] FIG. 1 schematically illustrates a prior art optical microscope.

[0012] FIG. 2 schematically illustrates an exemplary embodiment of a microscope according to the present invention.

[0013] FIG. 3 schematically illustrates an exemplary embodiment of a microscope according to the present invention.

[0014] FIG. 4 schematically illustrates an exemplary embodiment of a microscope according to the present invention.

[0015] FIG. 5 schematically illustrates an exemplary embodiment of a microscope according to the present invention. Detailed Description of the Invention

[0016] The invention provides miniaturized and portable microscope systems that minimize space requirements thereby allowing miniaturization, portability and other special functionalities.

[0017] Referring to FIG. 1 (Prior Art), which shows an example of a typical digital optical microscope 100. The digital optical microscope 100 includes an objective lens set 120 proximal to an object (specimen) 110, a projection lens 142, and an image sensor 150 placed at the focal point of the projection lens 142 for recording image of the object. When using infinity-corrected objective lens design, a tube lens 141 is placed between the objective lens set 120 and the projection lens 142. Optical filter or filters 145 may be use to alternate the characteristics of light projected to the image sensor or eyepiece.

[0018] The objective lens set 120 is commonly composed of a few lens, for example

hemispherical front lens 121, the first lens group 122, and the second group 123, with the first and second lens groups separated by a spatial distance in between.

[0019] Conventional objective lens sets are generally too large to fit in a compact digital microscope. The present invention addresses the problem through a unique folding design of the objective lens. As shown FIG. 2, which is a schematic illustration an exemplary microscope 200 according to the invention, the spatial dimension of the objective lens set can be greatly reduced by adding a reflective mirror or prism 225 between the first lens group 222 and the second lens group 223. Light collected from object 210 first by front lens group 221 and the first lens group 222, is reflected by a mirror or prism 225, and then passes through the second lens group 223 and ultimately projected on image sensor 250. When needed a tube lens 241 can be installed in the optical path. When high magnification is desired, a projection lens 242 can be added between the focal plane and the image sensor 250. Optical filter or filters 245 may be use to alternate the characteristics of light projected to the image sensor or eyepiece.

[0020] To further reduce its dimension, a compact digital microscope can be designed to fit into a compact enclosure, e.g., a cubic or cylindrical enclosure. This can be achieved by adding one, two or three reflective mirrors or prisms into the optical path, as shown in a top view in FIG. 3, which schematically illustrates an exemplary embodiment of the invention. To minimize the height of the microscope, this invention uses a folding objective lens set as shown in FIG. 2. A light beam from the object is first collected by front lens group 321 and passes first lens group 322, reflected and redirected by a mirror or prism 325, then exits the objective lens unit through the second lens group 323. Depending on the focal length or reference focal length (formerly referenced as optical tube length), one to three reflective mirrors or prisms 331, 332 and 333 are added to the optical path, which serve to redirect the light beam in order to reduce the overall dimensions of the microscope. When needed, a tube lens 341 can be added to the optical path. When a high magnification is desired, an image projection lens can be added between the focal plane and the image sensor 350. Optical filter or filters 345 may be use to alternate the characteristics of light projected to the image sensor or eyepiece.

[0021] FIG. 4 depicts one cross-sectional view (AA of FIG. 3), which is similar to the configuration of FIG. 2. FIG. 5 depicts another cross-sectional view (BB of FIG. 3), which shows that the image sensor 350 is disposed adjacent to the objective lends set 320. Thus, this exemplary embodiment allows a compact microscope with excellent performance.

[0022] The compact digital microscopes of the invention can be manually focused or automatically focused dependent on the application.

[0023] Compact digital microscopes introduced in FIG. 2 and FIG. 3 can be mounted on a one axis, two axes or rotating stage. With automated, scanning or remote monitoring applications, the compact digital microscope can be mounted on a controlled platform, to monitor different areas of the object. The microscope can be controlled to move in one dimension, two dimensions or on a rotating platform.

[0024] Thus, in one aspect, the invention generally relates to a compact microscope. The compact microscope includes (1) an objective lens set comprising a first lens group of two or more lens proximal to the objective end of the objective lens set, (2) a light reflecting component, and (3) a second lens group of lens proximal to the viewing or imaging end of the objective lens set. The light reflecting component is disposed between and in the optical path of the first lens group and the second lens group such that the angle between the incidental beam and the reflective beam is less than about 120°.

[0025] In certain embodiments, the microscope is a digital microscope comprising an imaging sensor converting an image of the object into digital and/or video data. In certain embodiments, the microscope is a conventional viewing microscope.

[0026] In certain preferred embodiments, the angle between the incidental beam and the reflective beam is less than about 100° (e.g., about or less than about 95°, about or less than about 90°, about or less than about 85°, about or less than about 80°, about or less than about 75°, about or less than about 70°).

[0027] In certain preferred embodiments, the objective lens set further includes a front lens group for collecting light from an object being imagined.

[0028] In certain preferred embodiments, the digital microscope includes an imaging component comprising a charge-coupled device image sensor. In certain preferred embodiments, the digital microscope includes an imaging component comprising a complementary metal-oxide semiconductor image sensor.

[0029] Any suitable magnification may be designed. In certain embodiments, the microscope is capable of magnification on the order of at least 10X (e.g., 10X - 100X, 100X - 1000X). In certain preferred embodiments, the microscope is capable of magnification on the order of at least 100X.

[0030] Any suitable light reflective device may be used to re-direct light beam as contemplated herein. In certain preferred embodiments, the light reflecting component is a mirror. In certain preferred embodiments, the light reflecting component is a prism. In certain preferred

embodiments, the digital microscope further includes an observation unit comprising an ocular lens. A mirror refers to an object that reflects light in a way that preserves much of its original quality subsequent to its contact with the mirror. A mirror may be a substrate such as glass, plastic or metal, with a surface coated with a reflective material.

[0031] In another aspect, the invention generally relates to a compact objective lens unit suitable for use in an optical microscopic system. The compact objective lens unit includes a first lens group of two or more lens proximal to the objective end of the objective lens set, a light reflecting component, and a second lens group of lens proximal to the viewing or imaging end of the objective lens set. The light reflecting component is disposed between and in the optical path of the first lens group and the second lens group such that the angle between the incidental beam and the reflective beam is less than about 120° (e.g., less than about 1 10°, less than about 100°, less than about 90°, less than about 80°, less than about 70°).

[0032] In certain preferred embodiments, the angle between the incidental beam and the reflective beam is less than about 90°. In certain preferred embodiments, the objective lens set further comprises a front lens group for collecting light from an object being imagined. [0033] In certain preferred embodiments, the compact objective lens unit has a dimension of less than about 200 mm X about 200 mm X about 100 mm (e.g., less than about 150 mm X about 150 mm X about 50 mm, less than about 120 mm X about 120 mm X about 40 mm, less than about 100 mm X about 100 mm X about 40 mm, less than about 80 mm X about 80 mm X about 30 mm, less than about 60 mm X about 60 mm X about 25 mm).

[0034] In certain preferred embodiments, the compact objective lens unit has a dimension of less than about 200 mm X about 50 mm X about 50 mm (e.g., less than about 150 mm X about 50 mm X about 50 mm, less than about 120 mm X about 50 mm X about 40 mm, less than about 100 mm X about 50 mm X about 40 mm, 100 mm X about 50 mm X about 30 mm, 100 mm X about 50 mm X about 25 mm).

[0035] In certain preferred embodiments, the compact objective lens unit has a circular outer boundary with a diameter less than about 200 mm (e.g., less than about 150 mm, less than about 100 mm, less than about 80 mm X, less than about 60 mm, less than about 50 mm, less than about 40 mm, less than about 30 mm, less than about 25 mm, less than about 20 mm).

[0036] In certain preferred embodiments, the light reflecting component is a mirror. In certain preferred embodiments, the light reflecting component is a prism.

[0037] In certain preferred embodiments, the light reflecting component is a mirror. In certain preferred embodiments, the light reflecting component is a prism.

[0038] In yet another aspect, the invention generally relates to a compact microscope. The compact microscope includes: an objective lens unit that includes a front lens group, a first lens group of two or more lens proximal to the objective end of the objective lens set, a first light reflecting component, and a second lens group of lens proximal to the viewing or imaging end of the objective lens set. The first light reflecting component is disposed between and in the optical path of the first lens group and the second lens group such that the angle between the incidental beam and the reflective beam is less than about 90° (e.g., less than about 85°, less than about 80°, less than about 75°, less than about 70°). The compact microscope further includes: a second light reflecting component or set; a projection lens set (or an eye piece); and an image sensor or a viewing window. The second light reflecting component or set folds the optical path such that the optical path directs the light beam to the imagine sensor or viewing window disposed adjacent the objective lens unit. [0039] In yet another aspect, the invention generally relates to a compact microscope comprising an objective lens unit and an imagine sensor or viewing window disposed adjacent the objective lens unit.

[0040] In certain preferred embodiments, the objective lens unit comprising a front lens group, a first lens group of two or more lens proximal to the objective end of the objective lens set, a first light reflecting component, a second lens group of lens proximal to the viewing or imaging end of the objective lens set, and one or more (e.g., two, three, four, five six, seven, eight or more) light reflecting components disposed along the optical path from the object to the imaging sensor or viewing window.

[0041] The compact microscope may assume any suitable outer shape, for example, having a substantially polygon-shaped outer boundary or having a substantially circular outer boundary.

[0042] In certain preferred embodiments, the digital microscope includes an imaging component comprising a charge-coupled device image sensor. In certain preferred embodiments, the digital microscope comprising an imaging component comprising a complementary metal- oxide semiconductor image sensor. In certain preferred embodiments, the light reflecting component is a mirror. In certain preferred embodiments, the light reflecting component is a prism.

[0043] The compact microscope may further include a light source for illuminating an object and may further include a fiber optic bundle for transmitting and directing a light beam (e.g., a fluorescent excitation light beam) from the light source. In certain preferred embodiments, the compact microscope further includes a digital and/or video recording and processing unit. In certain preferred embodiments, the compact microscope further includes a zooming system configured to continuously vary a magnification of the microscope over a magnification range.

[0044] The compact microscope may further include a beam splitter, an eyepiece for viewing and a camera comprising an image sensor for digital and/or video recording.

[0045] In this specification and the appended claims, the singular forms "a," "an," and "the" include plural reference, unless the context clearly dictates otherwise.

[0046] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described.

Methods recited herein may be carried out in any order that is logically possible, in addition to a particular order disclosed.

Incorporation by Reference

[0047] References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made in this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material explicitly set forth herein is only incorporated to the extent that no conflict arises between that incorporated material and the present disclosure material. In the event of a conflict, the conflict is to be resolved in favor of the present disclosure as the preferred disclosure.

Equivalents

[0048] The representative examples are intended to help illustrate the invention, and are not intended to, nor should they be construed to, limit the scope of the invention. Indeed, various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including the examples and the references to the scientific and patent literature included herein. The examples contain important additional information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof.

What is claimed is: