WO2013063097A1 - Optical objective having five lenses with front focusing - Google Patents

Abstract

Optical system comprising five lenses, a front pupil and achieving focus for objects from close to infinity by adjusting, via a MEMS actuator, the position of a subset of lenses located on the object-side of the optical system. The most object-side, biconvex, lens provides a substantial amount of the system's optical power for achieving focus from an object as close as 10 cm away from the aperture stop.

Description

OPTICAL OBJECTIVE HAVING FIVE LENSES WITH FRONT FOCUSING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U. S. Provisional Patent

Application Serial No. 61/550,789 entitled "OPTICAL SYSTEM WITH

MICROELECTROMECHANICAL SYSTEM IMAGE FOCUS ACTUATOR" filed October 24, 2011. The entirety of the above-noted application is incorporated by reference herein.

TECHNICAL FIELD

[0002] The following relates generally to imaging optics, and more particularly to a compact optical lens system with micro electromechanical system (MEMS) actuator for focusing the optical lens system.

BACKGROUND

[0003] Applications for optics and optical devices have become numerous in conjunction with advances in optical fabrication technology. One interesting advancement in optical technology is fabrication of micro lenses, and other optical components on a millimeter or micrometer scale, or less. Compared with traditional optical elements typically on the scale of centimeters or larger, micro optics have made optical systems compatible with smaller devices than traditional telescopes, microscopes, cameras, and so on.

[0004] One mechanism facilitating the fabrication of micro optics is wafer-level optics. Wafer-level optics is a fabrication technology that enables design and manufacture of optical components using techniques similar to semiconductor manufacturing. The technology is generally scalable with different size scales (e.g., millimeter, micrometer, etc.). Moreover, wafer-level optics can produce single-element as well as multi-element optical structures, yielding precision aligned stacks of lens elements. The end result of wafer-level optics provide cost effective, miniaturized optical components that enable reduced form factor for optical systems. These optical systems can be employed in a wide range of small or miniature devices, including camera modules for mobile phones, surveillance equipment, miniature video cameras, and the like.

[0005] Although wafer-level optics is one relatively recent technology for fabricating small optical components, some traditional fabrication techniques have been adapted to small-scale optical fabrication as well. For instance, plastic fabrication techniques including injection molding, and others can be employed for manufacturing small-scale optical components. Further, glass fabrication techniques have been adapted for miniaturized optical components, providing high quality optical surfaces for small- scale devices.

[0006] In addition to optical elements, the miniaturization of digital imaging sensors has also facilitated the continuing miniaturization of image capture and recording devices. Improvements in image sensors have provided high resolution image detectors utilizing micro-scale pixilation, and at high signal to noise ratio and increasingly lower cost. In conjunction with micro optics, such as wafer-level optical components, small, relatively inexpensive digital capture and recording devices can match or exceed the capabilities of relatively expensive, yet very high quality camera systems utilizing traditional optics of just a decade ago. Although quality is very high for modern micro optical devices, one persistent limitation has been zoom capability for miniature optical systems. One solution has been the introduction of digital zoom, which sacrifices optical resolution to enlarge an image. For high resolution sensors, this often provides a suitable alternative to traditional optical zoom capability. However, optical zoom provides advantages that digital zoom cannot achieve.

[0007] For example, the inventors of the disclosed subject matter suggest it would be desirable to have a miniature optical system with optical auto-focus capability. Such an optical system that achieves close focus would be additionally desirable.

SUMMARY

[0008] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0009] Particular aspects of the subject disclosure provide a miniaturized optical system. In some aspects, the miniaturized optical system can comprise an injection molded optical system. In further aspects, the miniaturized optical system can be an auto-focus optical system comprising five optical components. In still other aspects, the miniaturized optical system can be an auto-focus optical system employing a micro electromechanical system (MEMS) actuator to achieve focusing of the optical system.

[0010] In one or more other aspects of the subject disclosure, provided is an optical system that employs a MEMS actuator to achieve close focus. In one such aspect, the close focus can comprise a substantially 10cm object distance. Further, according to other aspects, the optical system can be configured to achieve close focus and infinity focus by adjusting position of a subset of optical components of the optical system. In particular aspects, the subset of optical components can comprise a single optical component of the optical system. In at least one such aspect, the single optical component can be a lens closest along an optical axis of the optical system to an object being imaged by the optical system (referred to as an object-side lens). In such aspect(s), the MEMS actuator can be configured to displace the object-side lens of the optical system a first distance configured to focus an object at infinity onto an image sensor associated with the optical system, and to displace the object-side lens a second distance configured to focus a close object (e.g. , an object substantially 10cm from the object-side lens) onto the image sensor.

[0011] According to one or more additional aspects, an auto-focus optical system disclosed herein can be configured to include an aperture stop. In a particular aspect, the auto-focus optical system can comprise injection molded plastic lenses, whereas in other aspects, the auto-focus optical system can comprise wafer-level optical lenses, glass lenses, or a suitable combination thereof. In another aspect, the aperture stop can be positioned on an object side of the object-side lens of the optical system. In one alternative aspect, a MEMS actuator can be configured to move a subset of optical components of the optical system to focus an object, while maintaining the aperture stop in a fixed position along an optical axis of the optical system. In another alternative aspect, the MEMS actuator can instead be configured to move both the subset of optical components and the aperture stop relative to the optical axis, to focus the object.

[0012] According to still other aspects, disclosed is an auto-focus optical system comprising a plurality of optical components. The plurality of optical components can, in some such aspects, comprise an object-side lens providing a substantial amount of optical power to the optical system. In at least one such aspect, the object-side lens can comprise substantially half or greater than half of the combined focal length of the optical system. In another aspect, the object-side lens can comprise substantially three- quarters or more of the combined focal length of the optical system. In a particular aspect, a MEMS actuator is connected to the object- side lens, and is configured to displace the object-side lens a first distance configured to focus an object at infinity, and a second distance configured to focus an object close to the optical system. According to one specific embodiment, a ratio of the focal length of the object-side lens and of a combined focal length of the optical system can be a function of a difference in magnitude of the first distance and the second distance along an optical axis of the optical system.

[0013] According to additional aspects, the subject disclosure provides a micro- optical system comprising five optical lenses. In one such aspect, an objective lens of the five optical lenses can be configured to supply all positive refractive power of the five optical lenses. In this aspect, the remaining four lenses have a combined net negative refractive power. In at least one particular aspect, the remaining four lenses can have respective negative refractive powers, with a combined net negative refractive power. According to an alternative or additional aspect, a third lens of the five optical lenses can a convex object side surface and a concave image side surface. As yet another alternative or additional aspect, a spacing between a fourth of the five optical lenses and a fifth of the five optical lenses can be a largest spacing between lenses of the optical system. In another aspect, the micro-optical system can be an auto-focus system in which a subset of the five optical lenses are movable along an optical axis to refine a focus of the optical system. In one specific aspect, the subset of the five optical lenses can comprise the objective lens, and the subset being movable by a MEMS actuator.

[0014] In further aspects of the subject disclosure, provided is a micro-optical system comprising five optical lenses. The five optical lenses can be arranged into a plurality of lens groups, each lens group comprising respective subsets of the five optical lenses. Each group comprises inter- lens distances equal to or less than a distance(s) between the plurality of optical groups. In a further aspect, each lens within at least one of the plurality of lens groups comprises at least one optical surface having both a concave portion and a convex portion. In a particular aspect, an effective focal length of the micro-optical system varies in response to a change in position along an optical axis of a first lens of the five optical lenses, and in an alternative or additional aspect, a back focal length of the micro-optical system remains substantially the same in response to the change in position along the optical axis of the first lens. [0015] To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more aspects. These aspects are indicative, however, of but a few of the various ways in which the principles of various aspects can be employed and the described aspects are intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 illustrates a diagram of an example optical imaging system configured to focus a relatively close object, according to various aspects of the subject disclosure.

[0017] Figure 2 illustrates a diagram of a sample optical imaging system configured to focus an object substantially at infinity, according to other disclosed aspects.

[0018] Figure 3 depicts a diagram of an example optical imaging system comprising a plurality of injection molded optical components.

[0019] Figure 4 illustrates a diagram of example field curvature and distortion graphs for a sample optical imaging system focusing a relatively close object.

[0020] Figure 5 illustrates a diagram of example field curvature and distortion graphs for the sample optical imaging system of Figure 4, focusing an object substantially at infinity.

[0021] Figure 6 depicts a diagram of a sample lateral color graph for an example optical imaging system focusing a relatively close object, according to further aspects.

[0022] Figure 7 illustrates a diagram of a sample lateral color graph for the example optical imaging system of Figure 6 focusing an object substantially at infinity, according other aspects.

[0023] Figure 8 depicts a diagram of transverse ray fan plots for a disclosed optical imaging system with an object focused at 10cm.

[0024] Figure 9 illustrates a diagram of transverse ray fan plots for the disclosed optical imaging system of Figure 8, with an object focused substantially at infinity.

[0001] Figure 10 illustrates a cross-section of a sample optical system for focusing an image of an object at 10cm according to aspects of the subject disclosure. [0002] Figure 11 illustrates a cross-section of a sample optical system for focusing an image of an object at infinity according to aspects of the subject disclosure.

[0003] Figure 12 illustrates an example graph of field curvature and distortion for an object at 10cm according to aspects of the subject disclosure.

[0004] Figure 13 illustrates an example graph of field curvature and distortion for an object at infinity in other aspects of the subject disclosure.

[0005] Figure 14 illustrates an example graph of primary lateral color for an object at 10cm according to an aspect(s).

[0006] Figure 15 illustrates an example graph of primary lateral color for an object at infinity according to one or more other aspects.

[0007] Figure 16 illustrates an example transverse ray fan plot for various image heights for an object at 10cm according to still other aspects.

[0025] Figure 17 illustrates an example transverse ray fan plot for various image heights for an object at infinity according to at least one other aspect.

[0026] Figure 18 depicts a transverse ray fan plot for a range of field angles for an example micro-optical system according to additional disclosed aspects.

[0027] Figure 19 illustrates a sample diagram of the micro-optical system of

Figure 18 including lenses and optical surfaces.

[0028] Figure 20 depicts an example graph of field curvature and distortion for an object focused by the micro-optical system of Figure 18.

[0029] Figure 21 illustrates a sample graph of longitudinal aberration for a pupil radius of 0.90 millimeters in an aspect.

[0030] Figure 22 depicts an example graph of lateral color for a disclosed micro- optical system according to further aspects.

[0031] Figure 23 illustrates a transverse ray fan plot for a range of field angles for a micro-optical system focused in the near-field according to disclosed aspects.

[0032] Figure 24 depicts a sample diagram of the micro-optical system of Figure

23 including lenses and optical surfaces.

[0033] Figure 25 illustrates an example diagram of field curvature and distortion for a near-field object focused by the micro-optical system of Figure 23.

[0034] Figure 26 depicts a sample diagram of longitudinal aberration for pupil radius of 0.90 millimeters for a disclosed micro-optical system, in an aspect.

[0035] Figure 27 illustrates an example diagram of lateral color for a disclosed micro-optical system according to still other disclosed aspects. [0036] Figures 28 A, 28B, 28C and 28D illustrate diagrams of an example micro-optical system focused at infinity according to further aspects, and related optical performance graphs.

[0037] Figures 29 A, 29B, 29C and 29D depict the micro-optical system of

Figure 28 focused in the near-field and related optical performance graphs.

DETAILED DESCRIPTION

[0038] Various aspects are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It will be evident, however, that such aspect(s) can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more aspects.

[0039] In addition, it should be apparent that the teaching herein can be embodied in a wide variety of forms and that the specific structures or functions disclosed herein are merely representative. Based on the teachings herein one skilled in the art should appreciate that the disclosed aspects can be implemented independently of other aspects, and that two or more of these aspects can be combined in various ways. For example, an apparatus can be implemented and/or a method practiced using any number of the aspects set forth herein. In addition, an apparatus can be implemented and/or a method practiced using other structure and/or functionality in addition to or other than one or more of the aspects set forth herein. As an example, many of the apparatuses and lens systems disclosed herein are described in the context of providing high resolution optical imaging via compact fixed position optical lens arrangements. One skilled in the art should appreciate that similar techniques could apply to other optical lens architectures. For example, the lens arrangements used herein may be used in mechanical focus or auto-focus systems whereby the optical arrangement is automatically or manually displaced relative to the image plane.

[0040] In at least one aspect of the subject disclosure, an optical imaging system is provided. The optical imaging system can comprise a first group of lenses and a second group of lenses. The optical imaging system can be focused by repositioning the first group of lenses relative to the second group of lenses along an optical axis of the optical imaging system. In at least one aspect of the subject disclosure, the second group of lenses includes an image sensor for the optical imaging system. In particular aspects of the subject disclosure, the first group of lenses can comprise a single lens. For instance, the single lens can include an object-side lens, which is an optical element closes to an object side of the optical imaging system.

[0041] Referring now to the drawings, Figure 1 depicts a block diagram of an example optical system 100 according to aspects of the subject disclosure. System 100 comprises an arrangement of optical elements 102 positioned transverse to an optical axis 104. As utilized herein, an optical element refers to a single piece of refractive or reflective material at least partially transparent to electromagnetic radiation at least partially within the visible spectrum (e.g. , including wavelengths approximately 400 to 700 nanometers [nm]). Examples of suitable material include ground and polished glass, molded glass or glass formed from a replication molding process, wafer-level optics (WLO), injection-molded plastic, etched micro optics formed on an optical substrate, or the like. Additionally, an optical element will have at least one refractive or reflective surface. One example of an optical element utilized herein is an optical lens. An optical lens is an optical element comprising two opposing refractive surfaces, and an edge between the opposing surfaces that defines an outer diameter (for a circular lens) or perimeter of the lens, and an edge thickness of the lens. A typical arrangement of optical lenses includes a series of lenses 102 at least generally transverse to an axis (optical axis 104). It should be appreciated, however, that other possible arrangements can exist consistent with the subject disclosure. A "lens component" is defined herein as (A) a single lens element spaced so far from any adjacent lens element that the spacing cannot be neglected in computing the image forming properties of the respective lens elements, or (B) two or more lens elements that have adjacent lens surfaces either in full overall contact or so close together that any spacing between the adjacent lens surfaces are so small that the spacing(s) can be neglected in computing image forming properties of the two or more lens elements. Thus, some lens elements can also be lens components, and the terms "lens element" and "lens component" are not mutually exclusive terms. In addition, it should be appreciated that the term "optical component" is utilized herein to refer to a superset of items having significant properties related to imaging optical systems, and includes optical elements such as lens elements and lens components, as well as various optical stops including but not limited to aperture stops, but can also include various other items such as a thin film, a bandpass filter, a lowpass or highpass filter, a polarizing filter, a mirror, etc. [0042] Light entering the left side, or object side, of optical elements 102 can interact sequentially with respective elements (102) and exit the right side, or image side, of the elements 102, toward an optical sensor 106. It should be appreciated that not all light interacting with the left side of the optical elements 102 will be transmitted to the sensor 106; some light can be reflected off of respective elements (102), some light can be scattered away from the optical axis 104 and absorbed (e.g. , by an optical stop - not depicted), and so forth. However, in general, the optical elements 102 will receive light from an object on one side of the elements (e.g. , the left side) and form a real image of the object on an opposite side of the elements (e.g. , on the right side). The real image will be formed along the optical axis 104 a certain distance from the optical elements 102, called an image distance (ID). Notably, the ID depends primarily on a corresponding object distance (OD - distance between the object and the optical elements 102 along the optical axis 104) and a refractive power, or optical power, of the combined optical elements 102.

[0043] Sensor 106 can be a digital device comprising a multi-dimensional array

(e.g. , a two dimensional array) of electro-optical sensors, or pixels. Examples of such a device can include a charge-coupled device (CCD) array, or a complementary metal- oxide semiconductor (CMOS) array, or some other suitable array of optical sensors. Each electro-optical sensor, or pixel, of such array is configured to output an electric signal when irradiated with light. Furthermore, an amount of electric current for the electric signal is directly related to energy density of light irradiating the pixel.

Accordingly, by collecting output current levels from each pixel of the array, sensor 106 can digitally reproduce a two dimensional radiant energy pattern of light irradiating the sensor 106. Additionally, where the pixel surface or sensor plane of sensor 106 is placed at the above-mentioned ID, the two dimensional radiant energy pattern that is produced is that of a real optical image generated by optical elements 102. Accordingly, sensor 106 can be utilized to digitally reproduce that image. Resolution of a digital image generated by sensor 106 depends on a number of pixels within an active array of sensor 106. In addition, optical system 100 can comprise a cover plate 108 between the optical elements 102 and image sensor 106, as depicted by Figure 1.

[0044] As depicted by optical system 100, optical elements 102 can comprise five optical lenses, including lens LI , lens L2, lens L3, lens L4 and lens L5, from the object-side of optical elements 102 to an image-side of optical elements 102. As depicted, lens LI is a biconvex lens having positive optical power, having convex object- side and convex image- side surfaces, Rl and R2, respectively. Additionally, lens LI can have a relatively strong positive optical power, relative to lenses L2, L3, L4 and L5. In at least one aspect, lens LI can have a relatively strong positive optical power relative to a combination of lenses L2, L3, L4 and L5. In a particular aspect, lens LI can provide at least about half or more of the combined focal length of optical elements 102. In an alternative aspect, lens LI can provide substantially about three-quarters or more of the combined focal length of optical elements 102. In related aspects, the optical power of the object-side lens (Ll_power) can be about 1.25x the combined optical power of optical elements 102 (e.g. , Ll_power < 1.25*(Ll_power + L2_power + L3_p0Wer + L4power + L5_power)- In ^a particular aspect, an aperture stop Al can be positioned at or in front of an object-side of lens LI. Aperture stop Al is described in more detail below.

[0045] Lens L2 can have an overall negative optical power. Further, lens L2, in one aspect, can have a mildly concave object-side surface R3. In an alternative aspect, object-side surface R3 can be flat, with no optical power. As yet another alternative aspect, object-side surface R3 can be mildly convex. An image-side surface R4 of lens L2 can have concave curvature. Moreover, lens L2 can be configured to provide chromatic aberration correction for optical system 100. In at least one aspect, lens L2 can provide a majority of chromatic aberration correction for optical system 100.

[0046] Lens L3 comprises an object-side surface R5 and an image-side surface

R6. Object-side surface R5 can be mildly concave, in particular aspects. Moreover, image-side surface R6 can be convex. In a particular aspect, lens L3 can have a positive optical power.

[0047] Lens L4 comprises an object-side surface R7 and an image-side surface

R8. Object-side surface R7 can have convex curvature near optical axis 104.

Moreover, in at least one aspect of the subject disclosure, object-side surface R7 can transition to concave further from optical axis 104. Moreover, image-side surface R8 can be substantially flat with little or no optical power near optical axis 104, and transition to convex curvature away from optical axis 104. In an alternative aspect, image-side surface R8 can be convex near optical axis 104 having significant optical power for low to mid field angles, as well as convex away from optical axis 104. In a particular aspect, lens L4 can have positive power for low field angles (e.g. , field angles between zero and about 12 to 15 degrees). In another aspect, lens L4 can have small positive, small negative, or substantially zero optical power for medium field angles (e.g. , field angles between about 12 to 15 degrees and about 22 to 25 degrees). In yet another aspect, lens L4 can have small positive, small negative, or substantially zero optical power for for high field angles (e.g. , field angles between about 22 to 25 degrees and about 33 or more degrees, up to a maximum accepted field angle of optical system 100).

[0048] Lens L5 comprises an object-side surface R9 and an image-side surface

R10. Object-side surface R9 can have concave curvature for low and medium field angles. In at least one aspect, object-side surface R9 can transition to mildly concave or no curvature for high field angles. Image-side surface R10 can be concave near optical axis 104. Moreover, image-side surface R10 can transition from concave to convex for medium and high field angles, as depicted.

[0049] As depicted, optical elements 102 can have respective spaces (e.g. , air spacing) between respective lenses LI, L2, L3, L4 and L5. In at least one disclosed embodiment, a first on-axis distance between lens LI and L2 can be substantially small compared with a third on-axis distance between lens L3 and lens L4. In another embodiment, the first on-axis distance can be substantially small compared to a second on-axis distance between lens L2 and L3, and a fourth on-axis distance between lens L4 and L5, in addition to the third on-axis distance. In at least one embodiment, the second, third and fourth on-axis distances can be substantially similar in magnitude, at least in comparison with the first on-axis distance. In other embodiments, these relations between the first, second, third and fourth on-axis distances need not exist. For instance, other relationships between the first, second, third and fourth on-axis distances may exist instead.

[0050] In at least one aspect of the subject disclosure, a MEMS actuator can be connected at least to lens LI . The MEMS actuator can be configured to reposition lens LI along optical axis 104 to focus objects at different object distances. As one example, the MEMS actuator can change the first distance between lens LI and lens L2 to focus objects at differing object distances. In at least one aspect, the MEMS actuator can position lens LI a distance Dio_cm HO from lens L2 to focus onto sensor 106 an image of an object that is substantially 10 centimeters (cm) from a position of aperture stop Al on optical axis 104.

[0051] According to further aspects, aperture stop Al can be fixed relative to optical axis 104. In another aspect, aperture stop Al can be fixed relative to a position of lens LI . In the latter aspect, aperture stop Al can be moved by a MEMS actuator in conjunction with lens LI when focusing an image of an object. According to still other aspects, the MEMS actuator can be configured to move lens LI , either alone or in conjunction with aperture stop Al , a total distance along optical axis 104. The total distance can, in a particular aspect, at one end thereof focus an image of an object at infinity, and at an opposite end thereof, focus an image of an object substantially at 10cm from aperture stop Al . As utilized herein, an object at infinity includes an object distance that satisfies the paraxial approximation known in the art of optical imaging science. The paraxial approximation, broadly stated, refers to an object at such a distance that an angle - subtending a first optical ray that is parallel with optical axis 104 and a second optical ray that originates at a point on the object farthest from the optical axis and passes through optical axis 104 at aperture stop Al - is substantially zero degrees. In yet another aspect, lens LI can have a focal length that is at least in part a function of a magnitude of the total distance. In still other aspects, a ratio of the focal length of lens LI and a combined focal length of optical elements 102 can at least in part be a function of the magnitude of the total distance.

[0052] Because the pixel array of sensor 106 generates an electronic reproduction of a real image, data generated by sensor 106 (and other sensors disclosed herein) in the form of electric signals can be saved to memory, projected to a display for viewing (e.g. , digital display screen), edited in software, and so on. Thus, at least one application of optical system 100 is in conjunction with a digital camera or video camera comprising a digital display. Furthermore, optical system 100 and other optical systems included in the subject disclosure can be implemented in conjunction with a camera module of an electronic device. Such an electronic device can include a wide array of consumer, commercial or industrial devices. Examples include consumer electronics, including a cell phone, smart phone, laptop computer, net-book, PDA, computer monitor, television, flat-screen television, and so forth, surveillance or monitoring equipment, including commercial equipment (e.g. , ATM cameras, bank teller window cameras, convenience store cameras, warehouse cameras and so on), personal surveillance equipment (e.g. , pen camera, eyeglass camera, button camera, etc.), or industrial surveillance equipment (e.g. , airfield cameras, freight yard cameras, rail yard camera, and so on). For instance in consumer electronics, because optical system 100 can comprise optical components having physical dimensions on the order of a few millimeters or less, and because at least some of optical elements 102 can have a fixed position, system 100 and other disclosed systems are well suited for various types of mini or micro camera modules. It is to be appreciated, however, that the disclosed systems are not limited to this particular application; rather, other applications known to those of skill in the art or made known by way of the context provided herein, are included within the scope of the subject disclosure.

[0053] Figure 2 illustrates a diagram of an example optical imaging system 200 according to additional aspects of the subject disclosure. Optical imaging system 200 can comprise a set of optical elements 202 arranged transverse to an optical axis 204. Furthermore, optical elements 202 can be configured to focus an image onto an image plane 206 of an object located substantially at infinity from an aperture stop Al of optical imaging system 200. In at least one aspect, optical elements 202 can be substantially similar to optical elements 102 of Figure 1, supra, except for the first distance between lens LI and lens L2. Particularly, this first distance in optical imaging system 200 can be a distance DI FINITY 210 configured to focus the object located substantially at infinity, discussed above. Furthermore, as described at Figure 1, supra, aperture stop Al can, in one aspect, be fixed in position relative to optical axis 204. In an alternative aspect, aperture stop Al can be fixed in position relative to lens LI, and move along optical axis 204 with lens L2.

[0054] It should be appreciated that surfaces Rl through R10 of lenses LI through L5 of optical elements 102 and 202 (as well as other optical surfaces described throughout the subject disclosure) can be of varying shapes. In one aspect, one or more of the surfaces can be spherical surfaces. In other aspects, one or more of the surfaces can be conic surfaces. In yet other aspects, one or more of the surfaces can be aspheric surfaces, according to a suitable aspheric equation, such as the even aspheric equation:

CY²

(1) z = ^ _{+ + j}g-)_C 2y2 2 ^ ⁺∑ (^At * ^Y ' ) , where z is the sag height (in mm) of a line drawn from a point on the aspheric lens surface at a radial distance, Y from the optical axis to the tangential plane of the aspheric surface vertex, C is the curvature of the aspheric lens surface on the optical axis, Y is the radial distance (in mm) from the optical axis, K is the conic constant, and A; is the 1^TH aspheric coefficient, with the summation over even number i. However, these aspects are not to be construed as limiting the scope of the subject disclosure. Rather, various surfaces can be odd aspheric, or of an aspheric equation comprising even and odd coefficients.

[0055] Further to the above, it should be appreciated that lenses of optical elements 102 and 202 (and optical lenses of various other optical systems provided throughout the subject disclosure) can be made of various suitable types of transparent material, and formed according to various suitable processes for generating an optical quality surface. In one aspect, lenses LI through L5 can be ground and polished glass, where the glass is selected to have an index of refraction resulting in a desired effective focal length for the combined lenses LI through L5. In another aspect, the lenses can be an optical-quality injected molded plastic (or plastic of optical quality formed by another suitable method), wherein the plastic has an index of refraction suitable to provide the desired effective focal length. In at least one other aspect, the lenses LI through L5 can be etched from a transparent glass, crystalline or other suitable structure (e.g. , silicon dioxide - Si0₂ wafer) with a lithographic etching process similar to that used to etch semiconductor chips (e.g. , solid state memory chip, data processing chip). In a particular aspect, optical elements 102 and optical elements 202 can be described according to the optical prescription of Tables 1 - 9, below.

Lens Units Millimeters (mm)

Angular Magnification 1.183246

Table 1: General Optical Properties

Table 2: Field Type v. Real Image Height (in mm)

Table 3: Vignetting Factors for Fields of Table 2

Table 4: Wavelengths Used for Ray tracing Surface Type Radius Thickness Material Diameter Conic Notes

Object Standard Infinity 100 132.3188 0

1 Standard Infinity 0.18 2.036472 0

Stop Standard Infinity -0.1 1 .85939 0

3 EvenAsph 1.974507 0.637634 APEL5514ML 1.907153 0

4 EvenAsph -13.5665 0.166808 1 .939212 0

0 not

Standard

5 Infinity 0.049504 1 .939212 vignetting

6 EvenAsph 68.79989 0.528506 OKP4HT 1.951274 0

7 EvenAsph 2.992822 0.247886 1.977445 0

0 Vignetting

Standard

8 Infinity 0.09498 2 at 1 .000

9 EvenAsph 143.3822 0.902332 APEL5514ML 2.122436 0

10 EvenAsph -24.6284 0.367969 2.741479 0

11 EvenAsph 1.97917 0.596974 APEL5514ML 3.225637 0

12 EvenAsph 91 .68886 0.360983 4.127183 0

13 EvenAsph -3.10061 0.382215 APEL5514ML 4.395569 0

14 EvenAsph 3.497914 0.2251 4.876466 0

15 EvenAsph Infinity 0.3 N-BK7 5.271775 0

16 Standard Infinity 0.55 5.427336 0

Image Standard 0 0

Table 5: Surface Data Summary

Coefficient on r 16

0

R3 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.01683

Coefficient on r 6

0.019474

Coefficient on r 8

-0.03875

Coefficient on r 10

0.034171

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R4 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.01678

Coefficient on r 6

0.057631

Coefficient on r 8

-0.06199

Coefficient on r 10

0.029185

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R5 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.07378

Coefficient on r 6

0.078871

Coefficient on r 8

-0.04834

Coefficient on r 10

0.007991

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R6 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.20739

Coefficient on r 6

0.12271

Coefficient on r 8

-0.04163

Coefficient on r 10

0.006751

Coefficient on r 12

0 Coefficient on r 14

0

Coefficient on r 16

0

R7 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.15706

Coefficient on r 6

0.019487

Coefficient on r 8

-0.00924

Coefficient on r 10

0.001005

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R8 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

0.054595

Coefficient on r 6

-0.04501

Coefficient on r 8

0.010689

Coefficient on r 10

-0.00087

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R9 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.01701

Coefficient on r 6

0.02087

Coefficient on r 8

-0.00363

Coefficient on r 10

0.000212

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0 IO Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.07822

Coefficient on r 6

0.013989

Coefficient on r 8

-0.00152

Coefficient on r 10

6.37E-05 Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

Table 6: Surface Aspheric Coefficients

Table 7: Edge Thickness Data

14ML

14 20 1 1 1 1 1

15 N-BK7 20 1 1 .523605 1 .520769 1 .518274 1.515909 1.51452

16 20 1 1 1 1 1

17 20 1 1 1 1 1

Table 8: Index of Refraction Data

Table 9: F/Number Data

Table 9A: F/Number Data (Continued)

[0056] Table 1 provides general optical information for an embodiment of optical imaging systems 100 and 200. Table 2 provides image heights in the y axis, measured at the image sensor 106 or image sensor 206, for eight different optical fields, and provides weights for the respective fields. Table 3 includes vignetting data for the eight fields indicated in Table 2. Table 4 depicts wavelengths of respective rays traced in optical imaging systems 100 and 200, depicted at Figures 1 and 2. Table 5 provides a summary of general optical surface characteristics for the lenses of optical elements 102 and optical elements 202, including surface type, radius of curvature, thickness, material (from standard glass and plastic catalogues), diameter, conic constant, and notes regarding vignetting. Table 6 describes even aspheric coefficients for the surfaces of Table 5, whereas Table 7 provides edge thickness information for those surfaces. Table 8 provides index of refraction data for multiple wavelengths for the optical fields identified at Table 2. Tables 9 and 9A provide F/# data for those same wavelengths and optical fields.

[0057] Figure 3 illustrates a diagram of an example injection molded plastic optical system 300 (also referred to as system 300) according to further aspects of the subject disclosure. System 300 can be formed from multiple injection molded plastic components. In one embodiment, two or more of lenses LI, L2, L3, L4 and L5 can be formed from a single mold. In other embodiments, respective lenses can be formed from separate molds and assembled, as depicted, after molding. In other aspects, formation of lenses LI, L2, L3, L4 and L5 can result from another optical fabrication technique, such as wafer-level optic fabrication. In at least one disclosed aspect, system 300 can be substantially similar to optical imaging system 100. In another aspect, system 300 can be substantially similar to optical imaging system 200. According to yet other aspects, system 300 can comprise MEMS hardware configured to displace lens LI along optical axis 302 to achieve focusing at an image plane 304 of system 300. In a particular embodiment, system 300 can comprise lens surfaces Rl and R2 of lens LI, surfaces R3 and R4 of lens L2, surfaces R5 and R6 of lens L3, surfaces R7 and R8 of lens L4, and surfaces R9 and R10 of lens L5, that are substantially similar to surfaces Rl - R10 described at Figure 1, supra.

[0058] Figure 4 illustrates a diagram of field curvature and F-Tan(Theta)

Distortion (referred to hereinafter as distortion) for an optical imaging system as described herein. Particularly, Figure 4 illustrates field curvature and distortion for an object distance of 10cm, which can correspond with optical imaging system 100 of Figure 1, supra. The field curvature and distortion graphs utilize five wavelengths, having wavelengths of 0.470, 0.510, 0.555, 0.610 and 0.650 μιη, respectively, and have a maximum field angle of 33.391 degrees. The left-hand graph depicts field curvature in millimeters along a y-axis at an image plane of an optical imaging system. Field curvature data is depicted for Sagittal rays (delineated as 'S' on Figure 4) and Tangential rays (delineated as ' on Figure 4). As is clear from the graph, field curvature is minimal for sagittal rays over most of the image plane, and field curvature is within a few microns for tangential rays for most of the image plane, and several microns at the outer edge of the image plane (high y values).

[0059] The distortion graph on the right hand side also includes curves for the above five wavelengths. The distortion data is normalized to 0% at the optical axis. Throughout the image plane, distortion is less than about 1.5%, and less than one percent for low field angles.

[0060] Figure 5 depicts a diagram of field curvature and distortion for an optical imaging system focusing an object at infinity. Thus, the graphs of Figure 5 can correspond with optical imaging system 200 of Figure 2, supra. The field curvature and distortion graphs of Figure 5 employ graphs for the same wavelengths as for Figure 4, for a maximum field angle of 34.897 degrees. Field curvature includes lines for sagittal rays (S) for the indicated wavelengths, as well as transverse rays (T) for those same wavelengths. As depicted, field curvature for an object in focus at 10cm is within about +/- 50 microns.

[0061] Distortion at infinity varies a bit more than for the 10cm graph of Figure

4. Distortion is again normalized to 0% on the optical axis. The distortion ranges from about a half percent at medium field angles to about negative one and a half percent at the edge of the image plane. Total distortion for all field angles is about two percent.

[0062] Figure 6 illustrates a graph of primary lateral color for an optical imaging system as described herein. Particularly, the primary lateral color graph of Figure 6 is for an object in focus at 10cm object distance, and therefore can correspond with optical imaging system 100 of Figure 1, supra. The maximum field for the primary lateral color graph is 2.9560 mm, and ranges in wavelengths between 0.4700 and 0.6500 μιη. As depicted, lateral color variation is well within a half a micron for small field angles, varies to just over negative one microns for medium field angles, and becomes as large as about negative one and a half microns for higher field angles. Overall distortion remains below two microns for the image plane.

[0063] Figure 7 illustrates a graph of primary lateral color for an object in focus at infinity. Accordingly, Figure 7 can correspond with optical imaging system 200 of Figure 2, supra. Similar to Figure 6, the maximum field is 2.9560 mm for wavelengths between 0.4700 and 0.6500 μιη. For low and medium field angles, primary lateral color remains at or below about one half a micron. Only at larger field angles does the primary lateral color exceed half a micron, reaching a peak at just over about two microns at an edge of the image plane.

[0064] Figure 8 illustrates several transverse ray fan plots at an image plane of an optical imaging system described herein. Particularly, the transverse ray fan plots of Figure 8 correspond with an object in focus at 10cm object distance, and therefore can correspond with optical imaging system 100 of Figure 1, supra. The transverse ray fan plots depict transverse ray error (e_y) along a vertical axis, and pupil diameter (P_y) along the horizontal axis, for various image heights. Flatter plots indicate optimal performance and minimal error, whereas greater deviations along the vertical axis indicate greater transverse ray error. As is depicted by Figure 8, transverse ray error is minimal for near the optical axis (small image height), and generally increases with image height. The scale ranges from positive 25 microns to negative 25 microns along the x and y axis, respectively. The transverse ray fan plots include wavelengths between 0.470 and 0.650 wavelengths.

[0065] Figure 9 depicts several transverse ray fan plots for an object in focus at infinity, and therefore can correspond with optical imaging system 200 of Figure 2, supra. Similar to Figure 8, the plots exhibit minimal error near the optical axis, and generally low error for small pupil diameters at all field angles. At higher field angles and particularly higher pupil diameters, the transverse ray error increases. Generally, transverse ray error for the object at infinity is less than for the object at 10cm.

[0066] Referring now to the drawings, Figure 10 depicts a cross sectional view of an optical system 1000 for an object at 10cm comprising an arrangement of optical elements 1002 positioned in a like manner relative to an optical axis 1004. Light entering the left side, or object side, of optical elements 1002 can interact sequentially with respective elements 1002 and exit the right side, or image side, of the elements 1002, toward an image sensor 1006. The real image will be formed along the optical axis 1004 a certain distance from the optical elements 1002, called an image distance (ID). Notably, the ID depends primarily on a corresponding object distance (OD - distance between the object and the optical elements 1002 along the optical axis 1004) and a refractive power, or optical power, of the combined optical elements 102.

[0067] Sensor 1006 can be a digital device comprising a multi-dimensional array {e.g. , a two dimensional array) of electro-optical sensors, or pixels, which can include a CCD array, or a CMOS array, etc. Resolution of a digital image generated by sensor 1006 depends on a number of pixels within the sensor plane array 1008, which in turn is dependent on pixel area and total array area. Thus, for example, for relatively square pixels approximately 1.4 microns per side (1.96 square microns), a 0.4 cm square sensor array can comprise as many as 8.1 megapixels (Mp). Said differently, such a sensor would have resolution of about 8Mp. Because the pixel array generates an electronic reproduction of a real image, data generated by sensor 1006 in the form of electric signals can be saved to memory, projected to a display for viewing (e.g. , digital display screen), edited in software, and so on.

[0068] It should be appreciated that the optical imaging arrangement 1000 depicted in Figure 10 (and other optical imaging systems disclosed herein) is not intended to be drawn to scale. For instance, lens thicknesses, positions and heights are not necessarily depicted in proper proportion with actual sizes. Rather, arrangement 1002 is intended to provide a visual context of an imaging system to aid conceptual understanding of other aspects disclosed herein.

[0069] Optical system 1000 comprises a first lens LI , a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5 centered upon an optical axis 104. The lenses are numbered starting from the object side to the image side. Thus, lens LI is closest to the object, and lens L5 is closest to the image. Aperture Al can be embedded into lens LI , or can be fixed to LI physically. Accordingly, in this embodiment, aperture Al does not move relative to lens LI . In certain aspects of the disclosure, the aperture Al can have a 50μιη depth.

[0070] Lenses LI through L5 each have two opposed refracting surfaces. A radius of curvature for the respective surfaces is denoted by the letter "R" followed by a surface number, starting with the object side surface of lens LI. Thus, the surfaces in order from object side to image side are object side surface Rl and image side surface R2 of lens LI, object side surface R3 and image side surface R4 of lens L2, object side surface R5 and image side surface R6 of lens L3, object side surface R7 and image side surface R8 of lens L4, and object side surface R9 and image side surface R10 of lens L5. The respective surface identifiers (Rl , R2, R3, . . . , R10) are also utilized to represent the radius of curvature for the respective surfaces. Additionally, refractive index ¾ denotes the refractive index of the lens medium associated with the 1^th surface, and v_di is the Abbe number of the lens medium associated with the 1^th surface.

[0071] Lens LI can have a large positive refractive power, with both optical surfaces, Rl and R2, being convex. As utilized herein, the terms large or small refractive power (whether positive or negative) are intended to be relative to other lenses of a particular optical system. Thus, for instance, referring to lens LI as having large positive refractive power implies that lens LI has greater than average positive refractive power as compared with other positive power lenses of optical system 1000. Conversely, a lens having small positive refractive power for optical system 1000 will have less than the average positive refractive power.

[0072] In an embodiment, LI can be moveable relative to lenses L2-L5 and the sensor plane 1008. Movement can be achieved using MEMS or other appropriate actuators. In this embodiment, L2-L5 remain fixed relative to the image sensor plane 1008 and image sensor 1006. In some aspects of the disclosure, the range of movement of LI is around ΙΟΟμιη. The movement of LI allows optical system 1000 to maintain focus on objects at various distances. In Figure 10, the optical system 1000 is focused on an object at a distance of 10cm from the optical system. In Figure 2, the optical system 1100 is focused on an object at optical infinity.

[0073] In certain embodiments, there is an inverse relationship between the refractive power of LI and the range of motion required to focus on objects at various distances. An LI with a higher power requires a shorter range of movement to focus on objects at various distances and vice versa. According to some aspects of the disclosure, the axial gap, or distance between lenses LI and L2 at the optical axis is around 125μιη, with a gap of about 170 μιη at the clear aperture.

[0074] L2 can have a meniscus shape (having smaller thickness near the optical axis than away from the optical axis), with optical surface R3 being convex, and optical surface R4 being concave. In some aspects of the disclosure, lens L2 provides most of the chromatic correction for optical system 1000 and has negative refractive power. Lens L3 can be biconvex near the optical axis 1004 as optical surface R5 is convex near the optical axis 1004 and concave away from the optical axis 1004 and image side optical surface R6 is convex. According to some aspects of the disclosure, lens L3 can have a positive refractive power. In certain embodiments, L2 can be mounted on to L3, such that L2 is fixed to L3, and L2 does not touch an optical barrel that arranges lenses LI - L5 of optical system 1000 along optical axis 1004.

[0075] Lens L4 has a concave object side optical surface R7, and a convex shaped image side optical surface R8. Lens L5 can be meniscus shaped with a convex optical surface R9 near optical axis 1004 and optical surface R10 that is concave near the optical axis 104. [0076] It should be appreciated that surfaces R1-R10 (as well as other optical surfaces described throughout the subject disclosure, including optical surfaces for system 200 can be of varying shapes. In one aspect, one or more of the surfaces can be spherical surfaces. In other aspects, one or more of the surfaces can be conic surfaces. In yet other aspects, one or more of the surfaces can be aspheric surfaces, according to a suitable aspheric equation, such as the even aspheric equation:

[0077] (1) z = (A_; * Y ¹ ) , where z is the sag

height (in mm) of a line drawn from a point on the aspheric lens surface at a radial distance, Y from the optical axis to the tangential plane of the aspheric surface vertex, C is the curvature of the aspheric lens surface on the optical axis, Y is the radial distance

(in mm) from the optical axis, K is the conic constant, and A; is the i^th aspheric coefficient, with the summation over even number i. However, these aspects are not to be construed as limiting the scope of the subject disclosure. Rather, various surfaces can be odd aspheric, or of an aspheric equation comprising even and odd coefficients.

[0078] Further to the above, it should be appreciated that lenses L1-L5 of optical system 1000 (and the optical lenses of optical system 1100) can be made of various suitable types of transparent material, formed according to various suitable processes for generating an optical quality surface. In one aspect, the lenses L1-L5 can be ground and polished glass, where the glass is selected to have an index of refraction resulting in a desired effective focal length for the combined lenses L1-L5. In another aspect, the lenses can be an optical-quality injected molded plastic (or plastic of optical quality formed by another suitable method), wherein the plastic has an index of refraction suitable to provide the desired effective focal length. In at least one other aspect, the lenses L1-L5 can be etched from a transparent glass, crystalline or other suitable structure {e.g. , silicon dioxide - Si0₂ wafer) with a lithographic etching process similar to that used to etch semiconductor chips {e.g. , solid state memory chip, data processing chip).

[0079] According to various aspects, the lenses LI , L2, L3, L4 and L5 can be made of plastic {e.g. , APL5014, OKP4HT, or ZE-330R or another suitable plastic having similar refractive index and Abbe number, or a suitable combination thereof). In one specific aspect, lenses LI, L3, and L5 are made of one plastic {e.g. , APL5014) while lenses L2 and L4 are made of different plastics {e.g. , OKP4HT and ZE-330R respectively). It should be appreciated, however, that in other aspects the lenses can be of other materials having similar Abbe numbers or refractive indices instead.

[0080] Turning now to Figure 11, a cross-section of a sample optical system focused at infinity according to aspects of the subject disclosure is shown. The optical system 1100 of Figure 11 is similar to optical system 100, although optical system 1100 is focused on an object at infinity as opposed to at 10 cm. A difference between optical system 1100 and optical system 1000 is that LI is positioned at a different distance from the sensor 1106 relative to lenses L2-L5.

[0081] According to one specific aspect of the subject disclosure, a prescription for the respective lenses LI, L2, L3, L4 and L5 is provided in Tables 10-13, below. Table 10 lists general lens data for the respective lenses, and Table 11 lists surface data including radius of curvature (R) (in mm) near the optical axis, distance between surfaces, diameter of the respective lenses, and material of the respective lenses.

Furthermore, Table 12 provides aspheric constants A; for i = 2, 4, 6, 8, 10, 12, 14, 16 of equation (1), supra, for aspheric surfaces of Table 11, where the index "i" is denoted by "r" {e.g. , as generated in the optical design software program ZEMAX, available from ZEMAX Development Corporation). Table 13 provides refractive index n_; of the 1^th lens for a set of wavelengths. Table 14 provides a range of fields versus image height, Table 15 provides vignetting information for optical systems 1000 and 1100, Table 16 provides wavelength and weights used for the raytracing of Figures 10 and 11, Table 17 provides surface data for optical systems 1000 and 1100, including radius, thickness, material, diameter, and conic constant. Additionally, Table 18 provides edge thickness information for optical systems 1000 and 1100.

Back Focal Length 0.5015793

TTL 5.299934

Image Space F/# 2.415692

Paraxial Working F/# 2.415692

Working F/# 2.40149

Image Space NA 0.202684

Object Space NA 8.867272e-011

Stop Radius 0.8867272

Paraxial Image Height 2.856

Paraxial Magnification 0

Entrance Pupil Diameter 1.773454

Entrance Pupil Position 0

Field Type Real Image height in mm

Maximum Radial Field 2.856

Primary Wavelength 0.555μιη

Lens Units mm

Angular Magnification 1.39828

Table 10: General Properties for Optical Systems 1000 and 1100

(Optical Properties defined in Optical Design Software Zemax)

15 Standard Infinity 0.4913 6

IMA Standard Infinity 6.4

Table 11: Surface Data for Lens Elements for Optical System 1000 and 1100

Table 11: Continued

Coeff on r8 -0.0065254167

Coeff on rlO 0

Coeff on rl2 0

Coeff on rl4 0

Coeff on rl6 0

Surface R3

Coeff on r2 0

Coeff on r4 -0.15575931

Coeff on r6 0.11775238

Coeff on r8 -0.040496241

Coeff on rlO 0

Coeff on rl2 0

Coeff on rl4 0

Coeff on rl6 0

Surface R4

Coeff on r2 0

Coeff on r4 -0.17899613

Coeff on r6 0.13165259

Coeff on r8 -0.041877243

Coeff on rlO 0

Coeff on rl2 0

Coeff on rl4 0

Coeff on rl6 0

Surface R5

Coeff on r2 0

Coeff on r4 -0.034806957

Coeff on r6 -0.055196853

Coeff on r8 -0.0076170308

Coeff on rlO 0

Coeff on rl2 0

Coeff on rl4 0

Coeff on rl6 0

Surface R6

Coeff on r2 0

Coeff on r4 0.020581236

Coeff on r6 -0.0065040866

Coeff on r8 -0.018006387

Coeff on rlO 0

Coeff on rl2 0

Coeff on rl4 0

Coeff on rl6 0

Surface R7 Coeff on r2 0

Coeff on r4 0.17752822

Coeff on r6 0.0025820117

Coeff on r8 0.0073104429

Coeff on rlO -0.0065708267

Coeff on rl2 0

Coeff on rl4 0

Coeff on rl6 0

Surface R8

Coeff on r2 0

Coeff on r4 0.03288338

Coeff on r6 0.076502466

Coeff on r8 -0.06842281

Coeff on rlO 0.038984099

Coeff on rl2 -0.0076836467

Coeff on rl4 0

Coeff on rl6 0

Surface R9

Coeff on r2 0

Coeff on r4 -0.1830718

Coeff on r6 0.075510932

Coeff on r8 -0.034603365

Coeff on rlO 0.0066539539

Coeff on rl2 -0.00029016159

Coeff on rl4 0

Coeff on rl6 0

Surface RIO

Coeff on r2 0

Coeff on r4 -0.15124446

Coeff on r6 0.071176496

Coeff on r8 -0.029255744

Coeff on rlO 0.0080879291

Coeff on rl2 -0.0014220241

Coeff on rl4 0.00014276636

Coeff on rl6 -6.2275295e-006

Table 12: Aspheric Coefficients for Optical System 1000 and 1100

L2 OKP4-HT 20 1 1.6564 1.6458 1.6369 1.6291 1.6248

L3 APL5014 20 1 1.5518 1.5483 1.5452 1.5424 1.5408

L4 ZE-330R 20 1 1.5172 1.5139 1.5111 1.5084 1.5069

L5 APL5014 20 1 1.5518 1.5483 1.5452 1.5424 1.5408

Table 13: Index of Refraction for Optical Systems 1000 and 1100

Table 14: Field Type v. Real Image Height (in mm)

Table 15: Vignetting Factors for Fields of Table 2

Table 16: Wavelengths Used for Ray tracing

Object Standard Infinity Infinity 0 0

Stop Standard Infinity 0.05 1 .773454 0

2 Standard Infinity -0.204 1 .773454 0

3 EvenAsph 2.031 962 0.545 APL5014 1 .774436 -1 L1

4 EvenAsph -17.6099 0.124209 1 .867362 -1

5 EvenAsph 4.1 7831 9 0.3 OKP4HT 1 .941112 -1 L2

6 EvenAsph 1 .60308 0.351 957 2.054041 -1

7 EvenAsph 5.790688 0.644562 APL5014 2.132792 -1 L3

8 EvenAsph -2.41 795 0.20021 9 2.449247 -1

9 EvenAsph -0.991 91 0.365894 ZE-330R 2.5699 -1 L4

10 EvenAsph -1 .22358 0.511 697 2.686087 -1

11 EvenAsph 12.46394 1 .123586 APL5014 2.987795 -1 L5

12 EvenAsph 2.132428 0.341511 4.646312 -1

13 Standard Infinity 0.3 D263T 6 0 I RCF

14 Standard Infinity 0.4913 N-BK7 6 0

Image Standard Infinity 6.4 0 0

Table 17: Surface Data Summary

Table 18: Edge Thickness Data

[0082] Figure 12 illustrates a graph of field curvature and distortion for optical configuration 1002. Further, the field curvature and distortion values are displayed for several wavelengths ranging from 0.470μιη to 0.650μιη. Field curvature is within about 10 microns for these wavelengths for low field angles, and is less than 100 microns even at the perimeter of the image plane. Further, distortion is well within the range of two and negative two percent. As would be clear to one of skill in the art, aberrations are well compensated for by the subject optical arrangement 1002.

[0083] Figure 13 illustrates a graph of field curvature and distortion for optical configuration 1102. Further, the field curvature and distortion values are displayed for several wavelengths ranging from 0.470μιη to 0.650μιη. Field curvature is well within the range of +/- 100 microns, and distortion is well within the range of two and negative two percent. As would be clear to one of skill in the art, aberrations are well compensated for by the subject optical arrangement 1102.

[0084] Figure 14 depicts a graph of lateral color for optical arrangement 1002.

A maximum field for the graph is 2.8560mm. Additionally, the lateral color curve is over a range of wavelengths from 0.470μιη to 0.650μιη. The primary lateral color for an object in focus at 10cm is about -3.5μιη as depicted by the graph.

[0085] Figure 15 depicts a graph of lateral color for optical arrangement 1102 for an object in focus at infinity. A maximum field for the graph is 2.8560mm.

Additionally, the lateral color curve is over a range of wavelengths from 0.470μιη to 0.650μιη. The primary lateral color for the object in focus at infinity is about +0.8 microns.

[0086] Figure 16 and Figure 17 depict transverse ray fan plots for optical arrangements 1002 and 1102 respectively. The transverse ray fan plots depict transverse aberration (e_y and e_x) along the y and x axis for pupil diameters P_y and P_x. The transverse ray fan plots are made at image heights 0.000mm (1600 and 1700),

0.5710mm (1602 and 1702), 1.1420mm (1604 and 1704), 1.7140mm (1606 and 1706), 2.2850mm (1608 and 1708), 2.5700mm (1610 and 1710), and 2.8560mm (1612 and 1712). The plots are generally within acceptable ranges for optical imaging and accordingly, the optical arrangements 1002 and 1102 have good imaging quality.

[0087] Figure 18 illustrates a diagram of an example ray plot diagram for an optical system 1800 according to alternative aspects of the subject disclosure. System 1800 comprises an arrangement of optical elements 1802. Optical rays are depicted intersecting optical elements 1802 within a field of view of optical system 1800. On- axis rays are focused onto the optical axis at an image plane or focal plane associated with optical elements 1802, and rays originating at larger field angles are depicted as converging at farther distances from the optical axis at the image plane.

[0088] A left-most side of optical elements 1802 is an object side of optical system 1800, and a right-most side of optical elements 1802 is an image side of optical system 1800. A real image of the object is formed at the image plane of optical elements 1802 when optical elements 1802 are properly in focus. In at least one aspect of the subject disclosure, optical system 1800 can comprise a variable focus optical system, in which a subset of optical elements 1802 can be moved along the optical axis to bring an image of an object into focus at the image plane. In particular aspects, a set of positions of the subset of optical elements 1802 can correspond with a set of object distances having respective images in focus at the image plane. In other words, when the subset of optical elements 1802 is positioned at one of the set of positions, an object at a corresponding one of the set of object distances will be in focus at the image plane. A position of optical elements 1802 as depicted by Figure 18 and Figure 19, infra, illustrate an example arrangement in which optical elements of system 1800 are in a position to focus an object located at infinity onto the image plane. A position of optical elements 1802 as depicted by Figures 23 and 24, infra, illustrate an example arrangement in which the optical elements are in a position to focus a near-field object onto the image plane.

[0089] Figure 19 depicts a diagram of an example optical system 1900 comprising optical elements and optical surfaces according to additional aspects of the subject disclosure. Optical system 1900 can be substantially similar to optical system 1800. As indicated, optical system 1900 is configured to focus an image of an object located in the far-field {e.g. , at infinity).

[0090] Optical system 1900 can comprise a set of optical elements 1902 centered along an optical axis 1904. Optical elements 1902 can be configured to focus an image that can be captured by a sensor 1908. Sensor 1908 can comprise a multidimensional array of optical-sensitive pixels located at an image plane of sensor 1908. The optical-sensitive pixels can output electrical signals in response to electro-magnetic energy {e.g. , light) focused by optical elements 1902 upon sensor 1908. Moreover, the electrical signals can have characteristics related to optical characteristics of the electromagnetic energy. These electrical signals can be utilized to re-produce the image focused by optical elements 1902 and captured by sensor 1908, as described herein or known in the art. Optical system 1900 can also comprise a cover plate 1906 for sensor 1908. Cover plate can protect the optical-sensitive pixels of sensor 1908 from dust or other particles that might otherwise absorb or scatter electro-magnetic energy focused by optical elements 1902, thereby distorting the image.

[0091] Optical elements 1902 can comprise five optical lenses, including lens

LI, lens L2, lens L3, lens L4 and lens L5 (referred to collectively as lenses LI - L5). The optical lenses are numbered from left - the object side of optical system 1900 - to right - the image side of optical system 1900. The left-most lens, LI, is therefore also referred to herein as the object-side lens. Alternatively, lens LI can be referred to as an objective lens of optical system 1900.

[0092] As depicted, lens LI is a bi-convex lens having positive optical power, and having a convex object-side surface Rl and convex image-side surface R2.

Furthermore, lens LI can have a strong optical power relative to lenses L2, L3, L4 and L5 of optical elements 1902. In particular aspects, lens LI can have greater positive optical power than either of lenses L2, L3, L4 or L5. In a further aspect, LI can have greater positive optical power than any subset of lenses L2, L3, L4 and L5. In at least one alternative or additional aspect, lens LI can have greater positive optical power than the combination of lenses L2, L3, L4 and L5. As depicted, an aperture stop Al can be located about the object side surface Rl of lens LI .

[0093] Lens 2 can be a lens having a negative optical power. Lens L2 can have an object-side surface R3 and an image-side surface R4. Surface R3 can be mildly convex, in some aspects of the subject disclosure. In other aspects, surface R3 can be substantially flat with no significant optical power. In still other aspects of the subject disclosure, surface R3 can have a complex curvature that is convex for a subset of pupil radii (e.g. , a range of distances from optical axis 1904) of surface R3, and concave for a different subset of pupil radii of surface R3. As an example, surface R3 can have a concave curvature from the optical axis 1904 to a first pupil radius, and can have a convex curvature from the first pupil radius to a second pupil radius, where the second pupil radius is larger than the first pupil radius. An image side surface R4 can have a concave curvature, providing the majority of negative optical power of lens L2.

[0094] Lens L3 can be a meniscus lens having a convex curvature toward the object side of lens L3. As depicted, lens L3 comprises an object side surface R5 and image side surface R6. Object side surface R5 can have convex curvature. In particular aspects, convexity of object side surface R5 can be stronger near optical axis 1904 than near a perimeter of lens L3. Said differently, a radius of curvature of object side surface R5 can increase with increasing pupil radius of object side surface R5, and in at least one aspect become infinite near the perimeter of lens L3. Image side surface R6 can have concave curvature. In at least one aspect, a radius of curvature of image side surface R6 can increase with increasing pupil radius of lens L3. In an alternative or additional aspect, image side surface R6 can be convex near the perimeter of lens L3.

[0095] Lens L4 comprises an object side surface R7 and an image side surface

R8. Lens L4 can be a meniscus lens toward the image side of optical elements 1902. Additionally, lens L4 can have mild positive optical power. In one alternative or additional aspect, positive power of lens L4 can be greater near optical axis 1904 as compared with a periphery of lens L4, whereas in other aspects the positive power can be substantially constant over the surface of image side surface R8.

[0096] Lens L5 comprises an object side surface R9 and image side surface

R10. Object side surface R9 can have concave curvature for low and medium field angles, and reduced curvature at higher field angles. Image side surface R10 can be concave near optical axis 1904. Further, image side surface R10 can transition from concave to convex for medium and high field angles.

[0097] Optical elements 1902 can have respective spaces (air gaps) between respective lenses LI, L2, L3, L4 and L5. In a particular aspect, an on-axis air distance between lens L4 and lens L5 can be a largest of a set of air distances among lenses LI - L5. In an alternative or additional aspect, an air distance between lens L3 and lens L4 can be a second largest of the set of air distances among lenses LI - L5.

[0098] In a further aspect of the subject disclosure, an actuator can be connected to a subset of optical elements 1902. In one example, the actuator can be a MEMS actuator, whereas in other aspects the actuator can be another type of actuator known in the art. The actuator can be configured to reposition the subset of optical lenses along optical axis 1904. Repositioning the subset of optical lenses can cause images of objects at different object distances to come into focus at sensor 1908 of optical system 1900. In particular aspects, optical lenses 1902 can be configured to focus an image of an object located in the far field (e.g. , infinity, . . .) onto sensor 1908. According to further aspects, the subset of optical elements 1902 can be repositioned to focus an object in the near field at sensor 1908. In a specific aspect, the subset of optical elements can include lens LI, and lens LI can be positioned as depicted by Figure 19 by the MEMS actuator to bring an object located at infinity into focus at sensor 1908, and can be positioned as depicted by Figure 23 by the MEMS actuator to bring an object at an object distance of substantially 12.8 centimeters (cm) into focus at sensor 1908.

[0099] In a further aspect, aperture stop Al can be fixed relative to optical axis

1904. In another aspect, aperture stop Al can be fixed relative to a position of lens LI. In the latter aspect, aperture stop Al can be moved by a MEMS actuator in conjunction with lens LI when focusing an image of an object onto sensor 1908. According to still other aspects, the MEMS actuator can be configured to move lens LI , either alone or in conjunction with aperture stop Al , a total distance along optical axis 1904. The total distance can, at one end thereof, focus an image of an object at infinity on sensor 1908, and at another end thereof, focus an image of an object at an object distance of substantially 12.8cm at sensor 1908.

[00100] Lenses LI - L5 can be of various suitable types of suitable optically transparent material, and formed according to a suitable method(s) for generating an optical quality surface. In one aspect, lenses LI - L5 can be ground or polished glass, where the glass is selected to have an index of refraction resulting in a desired effective focal length for the combined lenses LI - L5. In another aspect, the lenses can be an optical-quality injection molded plastic (or plastic of optical quality formed by another suitable fabrication method), wherein the plastic has an index of refraction suitable to provide the desired focal length. In another aspect(s), the lenses LI - L5 can be etched from a transparent glass, crystalline or other suitable structure with a lithographic etching process similar to that used to etch semiconductor chips. In a specific aspect(s), lenses LI - L5 can be of differing glasses, plastics or suitable optical-transparent medium, by one or more of the above or similar suitable fabrication techniques (note that cover 1908 is a fictional material). In a further aspect, optical elements 1902 can have be described according to the optical prescription of Tables 19 - 27 A.

Exit Pupil Diameter 1.214476

Exit Pupil Position -3.231397

Maximum Radial Field 3.492

Lens Units Millimeters (mm)

Angular Magnification 1.482119

Table 1: General Optical Properties (Object in Focus at Infinity)

Table 20: Field Type v. Real Image Height (in mm)

Table 21: Vignetting Factors for Fields of Table 20

4 0.5876 0.80

5 0.6563 0.10

Table 22: Wavelengths Used for Ray tracing

Table 23: Surface Data Summary

R2 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.018496708

Coefficient on r 6

0.041017657

Coefficient on r 8

-0.14989043

Coefficient on r 10

0.18705355

Coefficient on r 12

-0.081043198

Coefficient on r 14

0

Coefficient on r 16

0

R3 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.04452888

Coefficient on r 6

0.1590456

Coefficient on r 8

-0.32756888

Coefficient on r 10

0.38155806

Coefficient on r 12

-0.15580658

Coefficient on r 14

0

Coefficient on r 16

0

R4 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.067461498

Coefficient on r 6

0.16544449

Coefficient on r 8

-0.23156178

Coefficient on r 10

0.20660588

Coefficient on r 12

-0.067541427

Coefficient on r 14

0

Coefficient on r 16

0

R5 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.10351059

Coefficient on r 6

0.083284677

Coefficient on r 8

-0.073446626

Coefficient on r 10

0.031355945

Coefficient on r 12

-0.005953706

Coefficient on r 14

0 Coefficient on r 16

0

R6 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.080839736

Coefficient on r 6

0.05806703

Coefficient on r 8

-0.042396061

Coefficient on r 10

0.013117216

Coefficient on r 12

-0.001392345

Coefficient on r 14

0

Coefficient on r 16

0

R7 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.061283862

Coefficient on r 6

0.056005953

Coefficient on r 8

-0.023784572

Coefficient on r 10

0.004382924

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R8 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

0.005176523

Coefficient on r 6

0.02067126

Coefficient on r 8

0.001625502

Coefficient on r 10

-0.001134584

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R9 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

0.019100544

Coefficient on r 6

-0.000208483

Coefficient on r 8

5.84E-05

Coefficient on r 10

-3.36E-06

Coefficient on r 12

0 Coefficient on r 14

0

Coefficient on r 16

0

RIO Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.038366245

Coefficient on r 6

0.004903112

Coefficient on r 8

-0.000509017

Coefficient on r 10

1.88E-05

Coefficient on r 12

1.99E-07

Coefficient on r 14

0

Coefficient on r 16

0

Table 24: Surface Aspheric Coefficients

Table 25: Edge Thickness Data

2R

4 20 1 1 1 1 1 1

5 20 1 1 1 1 1 1

6 EP5000 20 1 1.67140227 1.65459312 1 .64171 7 1 .635484 1 .628005

7 20 1 1 1 1 1 1

8 20 1 1 1 1 1 1

9 EP5000 20 1 1.67140227 1.65459312 1 .64171 7 1 .635484 1 .628005

10 20 1 1 1 1 1 1

11 20 1 1 1 1 1 1

ZEONF5

12 2R 20 ₁ 1.5467026 1.54130926 1.53688 1 .53462 1 .531786

13 20 1 1 1 1 1 1

14 20 1 1 1 1 1 1

ZEON 1 .541309

15 F52R 20 ₁ 1.5467026 26 1.53688 1.53462 1 .531786

16 20 1 1 1 1 1 1

MODE 1.5267041 1 .522378

17 L 20 ₁ 6 72 1 .51871 9 1.516798 1 .514329

18 20 1 1 1 1 1 1

19 20 1 1 1 1 1 1

Table 26: Index of Refraction Data

Table 27: F/Number Data

5 1 .357 2.7494 2.7781 2.7555 2.7831

6 1 .696 2.81 73 2.8375 2.824 2.841 7

7 2.035 2.9694 2.907 2.9763 2.91 06

8 2.375 3.2 2.9879 3.2054 2.9909

9 2.714 3.5125 3.0759 3.5143 3.0782

10 3.053 4.1 067 3.1 722 4.1 033 3.1 741

11 3.392 5.1347 3.2934 5.1255 3.295

12 3.492 5.7553 3.3499 5.7426 3.3515

Table 27A: F/Number Data (Continued)

[00101] Table 19 provides general optical information for an embodiment of optical systems 1800, 1900 of Figures 18 and 19, respectively. Table 20 provides image heights in the y axis, measured at the image sensor 1906 for a set of optical fields, and respective weights for the respective fields. Table 21 includes vignetting data for the set of optical fields of Table 20. Table 22 depicts wavelengths of respective rays traced in optical imaging system 1800, depicted at Figure 18. Table 23 provides a summary of general optical surface characteristics for lenses of optical elements 1902, including surface type, radius of curvature, thickness, material (from standard glass and plastic catalogues; not that a fictitious material is used for cover glass 1908), diameter, conic constant and applicable notes. Table 24 describes aspheric coefficients for the surfaces of Table 23, whereas Table 25 provides edge thickness information for those surfaces. Table 26 provides index of refraction data for multiple wavelengths for the optical fields identified at Table 20. Tables 27 and 27A provide F/# data for those same wavelengths and optical fields.

[00102] Figure 20 depicts a diagram of field curvature and distortion for the optical systems 1800, 1900 of Figures 18 and 19, supra. Particularly, the field curvature and distortion depicted in Figure 20 correspond with the optical elements 1902 configured to focus an image of an object at infinity onto sensor 1906. The field curvature and distortion graphs utilize five wavelengths, including 0.436, 0.486, 0.546, 0.588 and 0.656 μιη respectively. Moreover, the rays are traced with a maximum field of 35.543 degrees. The left-hand graph depicts field curvature in millimeters along a y axis at an image plane of an optical imaging system. Field curvature curves are depicted for Sagittal rays (delineated by an 'S') and Tangential rays (delineated by a 'T'). The range of field curvature over the utilized wavelengths is within a few microns for sagittal and tangential rays. The distortion graphs on the right-hand side of Figure 20 also includes curves for the above five wavelengths. The distortion data is normalized to 0% at the optical axis. Throughout the image plane, distortion is less than about -1%, and for mid to low field angles below about + / - one half a percent.

[00103] Figure 21 illustrates a diagram of longitudinal aberration for a set of wavelengths. Longitudinal aberration of Figure 21 relates to optical elements 1902, configured to image an object located at infinity onto sensor 1906. The listed wavelengths include 0.436, 0.486, 0.546, 0.588 and 0.656 μιη. The graph charts longitudinal aberration in millimeters for increasing field angles, for a pupil radius of 0.9mm. At low field angles the longitudinal aberration is generally positive and less than about 0.02 millimeters. At high field angles, the longitudinal aberration is more negative and generally less than about 0.03 millimeters. The longitudinal aberration graph of Figure 21 indicates optical elements 1902 provide reasonably good aberration correction for the identified wavelengths.

[00104] Figure 22 depicts a graph of lateral color for optical elements 1902 of Figure 19, supra. Accordingly, the graph of lateral color relates to optical elements 1902 configured to focus an image of an object located at infinity onto sensor 1906. The maximum field for the lateral color graph is 3.3920 millimeters, and wavelengths for the lateral color graph range from 0.4358 through 0.6563 μιη. In addition, data is referenced to 0.546100 μιη. For most field angles the lateral color is within about + / - 0.5 microns. At high field angles, lower wavelengths exhibit lateral color about -1 micron or greater, and higher wavelengths exhibit lateral color about 1 micron.

[00105] Figure 23 illustrates a diagram of an example optical system 2300 according to still other aspects of the subject disclosure. Optical system 2300 can comprise a set of optical elements 2302, as depicted. In at least one aspect of the subject disclosure, optical elements 2302 can comprise a set of lenses substantially similar to optical elements 1802 and 1902 of Figures 18 and 19, supra, but having a different focus position. Specifically, a subset of optical elements 2302 can be positioned in a manner suitable to focus an image of a near- field object at an image plane of optical elements 2302. As depicted, the near-field object position for optical elements 2302 is 12.8cm. By repositioning the subset of optical elements 2302 between the position depicted by Figure 23 and that of optical elements 1902 of Figure 19, optical system 2300 can focus different object distances between the near-field object and an object at infinity.

[00106] Optical system 2300 illustrates a set of ray fans representing light incident upon optical elements 2302 at discrete field angles. A field angle of zero is depicted by rays of light that converge at an optical axis of optical system 2300 at an image plane of optical elements 2302. Light converging at points on the image plane at increasing distances from the optical axis represent rays of light encountering optical elements 2302 at correspondingly larger field angles.

[00107] Figure 24 depicts a diagram of an example optical system 2400 according to still other aspects of the subject disclosure. Optical system 2400 delineates optical lenses and associated optical surfaces of optical system 2300 of Figure 23. Further, in at least one aspect, the optical lenses and associated optical surfaces of optical system 2300 can be substantially similar to the optical lenses and optical surfaces of optical systems 1800 and 1900 of Figures 18 and 19, supra. Optical system 2400 can differ from optical systems 1800 and 1900 in that optical elements 2402 can be configured to focus an image of an object located at substantially 12.8cm at a sensor 2408. Other aspects of optical system 2400 and optical elements 2402, including optical surfaces Rl and R2 of lens LI, R3 and R4 of lens L2, R5 and R6 of lens L3, R7 and R8 of lens L4, and R9 and R10 of lens L5. Further, sensor 2408 and cover glass 2406 can be substantially similar to sensor 1906 and cover glass 1908 of optical system 1900.

[00108] According to a particular aspect of the subject disclosure, optical elements 2402 comprise an object lens, lens LI, which is connected to an actuator (e.g. , MEMS actuator, ...) to facilitate auto-focusing for optical system 2400. In the arrangement of optical elements 2402 depicted by Figure 24, and in particular an air distance distance_near between lens LI and lens L2, optical elements 2402 are configured to focus a real image of an object at an object distance of 12.8cm onto sensor 2408. By moving lens LI into a position depicted by optical elements 1902 of Figure 19, where the air distance between lens LI and lens L2 is a distance^, optical system 2400 can be configured to focus an image of an object at infinity, instead. In at least one alternative or additional aspect of the subject disclosure, lens LI can be repositioned to change the air distance between distance_near and distance^, thereby focusing an image of an object located at points between 12.8cm and infinity at sensor 2408. Optical elements 2402 can have image characteristics as described by the optical characteristics of Tables 28 - 31A.

Parameter Description Value Effective Focal Length (in air at system temperature and pressure) 4.673877

Effective Focal Length (in image space) 4.673877

Back Focal Length -0.05732965

Total Track Length (TTL) 5.668093

Image Space F/# 2.596598

Paraxial Working F/# 2.747179

Working F/# 2.738746

Image Space NA 0.1 790633

Object Space NA 0.007028331

Stop Radius 0.9

Paraxial Image Height 3.492

Paraxial Magnification -0.03861711

Entrance Pupil Diameter 1 .8

Entrance Pupil Position 0.05

Exit Pupil Diameter 1 .1 98642

Exit Pupil Position -3.269722

Maximum Radial Field 3.492

Lens Units Millimeters (mm)

Angular Magnification 1.501698

Table 28: General Optical Properties (Object in Focus at ~12.8cm)

Table 29: Vignetting Factors for Fields of Table 20 Surface Type Radius Thickness Material Diameter Conic Notes

Object Standard Infinity 128 179.1413 0

1 Standard Infinity 0.05 2.060591 0 Stopl

Stop Standard Infinity -0.176644 1.8 0 A1

3 EvenAsph 2.024203 0.721 ZEONF52R 1 .872 -1 R1

4 EvenAsph -11.8344 0.08 1 .89 0 R2

5 Standard Infinity 0.1656548 2.015092 0 Stop 2

6 EvenAsph -250 0.32 EP5000 1 .91 0 R3

7 EvenAsph 2.745619 0.3434152 2.093864 0 R4

8 Standard Infinity 0.00302399 2.284414 0 Stop 3

9 EvenAsph 2.970147 0.3494011 EP5000 2.456709 0 R5

10 EvenAsph 3.958667 0.1844251 2.735497 0 R6

11 Standard Infinity 0.3353069 2.905287 0 Stop 4

12 EvenAsph -4.5388 0.5144013 ZEONF52R 3.007844 0 R7

13 EvenAsph -1.56458 0.2719004 3.349097 -1 R8

14 Standard Infinity 0.421506 5.039133 0 Stop 5

15 EvenAsph -3.33374 0.908 ZEONF52R 5.142131 0 R9

16 EvenAsph 3.980869 0.6500583 6.098372 0 R10

17 Standard Infinity 0.3 6.852322 0 CG 1908

18 Standard Infinity 0.1 7.029509 0

Image Standard Infinity 7.027898 0

Table 30: Surface Data Summary

Table 31: F/Number Data

1 0 2.7437 2.7437 2.7514 2.7514

2 0.339 2.7524 2.7528 2.7599 2.7603

3 0.678 2.7716 2.7793 2.7789 2.7865

4 1 .01 8 2.7909 2.8208 2.7981 2.8276

5 1 .357 2.81 77 2.8733 2.8251 2.8794

6 1 .696 2.8924 2.9347 2.9003 2.9401

7 2.035 3.0664 3.0075 3.0742 3.0122

8 2.375 3.3337 3.0937 3.339 3.0977

9 2.714 3.7016 3.1 884 3.701 3.1 91 7

10 3.053 4.372 3.2943 4.3618 3.2971

11 3.392 5.5698 3.4337 5.5469 3.436

12 3.492 6.3558 3.5014 6.3211 3.5037

Table 31A: F/Number Data (Continued)

[00109] Tables 28 - 31 A comprise optical characteristics and image

characteristics of optical system 2400 that differ from the configuration of optical system 1900. Table 28 provides general optical information for the embodiment of optical system 2400. Table 29 includes vignetting data for the set of optical fields of Table 20. Table 30 provides a summary of general optical characteristics for lenses of optical elements 2402, including surface type, radius of curvature, thickness, material (from standard glass and plastic catalogues, including a fictitious material for cover glass 2408), diameter, conic constant and applicable notes. Tables 31 and 31 A provide F/# data for identified wavelengths and optical fields.

[00110] Figure 25 illustrates a diagram of field curvature and distortion for the optical system 2400 of Figure 24, supra. Wavelengths employed for the field curvature and distortion graphs include 0.436, 0.486, 0.546, 0.588 and 0.656 μιη. Rays traced to generate these graphs have units in field angle with a maximum field of 34.188 degrees. The field curvature for both tangential and sagittal rays are generally positive and less than about 0.05 mm for all field angles. Distortion is less than about 1% for mid to low field angles, and increases to about 1.6% at high field angles.

[00111] Figure 26 illustrates a diagram of longitudinal aberration for optical system 2400. The longitudinal aberration graph is provided for five wavelengths, including 0.436, 0.486, 0.546, 0.588 and 0.656 μιη. The graph charts longitudinal aberration in millimeters for increasing field angles, and with pupil radius of 0.9mm. At low field angles the longitudinal aberration is generally positive and less than about 0.04 millimeters. At higher field angles, the longitudinal aberration ranges positive to negative for different field angles, and is generally between positive 0.03 millimeters and about negative 0.035 millimeters. [00112] Figure 27 depicts a graph of lateral color for optical elements 2402 of Figure 24, supra. The graph of lateral color relates to optical elements 2402 configured to focus an image of an object located at about 12.8cm onto sensor 2406. The maximum field for the lateral color graph is 3.3920 millimeters, and wavelengths employed for the graph range from 0.4358 through 0.6563_μιη. In addition, data is referenced to 0.546100 μιη. For all field angles the lateral color is less than about +3 microns and greater than about -1 microns. At low and mid field angles, the lateral color ranges between about +1 micron and about -0.25 microns.

[00113] Figures 28A - 28D illustrate an example optical system according to one or more additional aspects of the subject disclosure. The optical system is depicted at Figure 28A on the upper left in a configuration to focus an image of an object at infinity onto a sensor of the optical system. Figures 29A - 29D illustrate the example optical system in a configuration to focus an image of a near-field object onto the sensor of the optical system. The latter configuration can be achieved, for instance, by decreasing an air distance between the first left-most lens closest to the object side of the optical system, closer to the second lens on the object side of the optical system.

[00114] Generally, the optical system comprises five lenses, from an object side to image side, including lens LI (also referred to as an objective lens), lens L2, lens L3, lens L4 and lens L5 (referred to collectively as lenses LI - L5). Moreover, the optical system of Figures 28 A - 28D can comprise two or more lens groups, defined at least in part on an on-axis inter- lens air distance between respective lenses of the two or more lens groups. As an example, the five lenses of the optical system can be arranged into two lens groups, a first of the lens groups comprising a first lens, second lens and third lens from the object side of the optical system, and where the second of the lens groups comprising a fourth lens and fifth lens from the object side of the optical system. The lens groups can be constrained to have on-axis air distances between lenses that is smaller than an on-axis air distance between the first and the second lens groups.

[00115] Figures 28B - 28D illustrate image characteristics for the optical system of Figure 28A configured to focus an image of an object at infinity on a sensor of the optical system (far field focus configuration). Figures 29B - 29D illustrate image characteristics for the optical system of Figure 29A configured to focus a near-field object on the sensor (near field focus configuration). Figure 28B depicts a graph of field curvature and distortion for the far field focus configuration, with a maximum field greater than about 32 degrees for wavelengths between about 0.47 and about 0.65 microns. Figure 28 C illustrates a graph of longitudinal aberration for the far field configuration at the above wavelengths, and for a pupil radius of about 0.991mm, and Figure 28D depicts a graph of lateral color for this configuration having a maximum field of about 2.956 millimeters having data referenced to wavelength of about 0.555 microns.

[00116] Figure 29B illustrates field curvature and distortion for the near field configuration of the optical system, depicted at Figure 29A. The field curvature and distortion has a maximum field of about 34.51 degrees for wavelengths between about 0.470 and about 0.650 microns. Figure 29C depicts longitudinal aberration for the near field configuration with pupil radius of about 0.991 millimeters and wavelengths of about 0.470, 0.510, 0.555, 0.610 and 0.650 microns. Figure 29D illustrates a graph of lateral color for the near field configuration, with a maximum field of about 2.9560 millimeters and with data referenced to wavelength of 0.555 microns. The optical system of Figures 28A and 29A are described by the optical and image characteristics provided by Tables 32 - 40A, below.

Maximum Radial Field 2.956

Lens Units Millimeters (mm)

Angular Magnification 1.400838

Table 32: General Optical Properties (Object in Focus at Infinity)

Table 33: Field Type v. Real Image Height (in mm)

Table 34: Vignetting Factors for Fields of Table 20

Table 35: Wavelengths Used for Ray tracing Surface Type Radius Thickness Material Diameter Conic Notes

Object Standard Infinity Infinity 0 0

Stop Standard Infinity -0.05 1 .762 0 Stop

2 Standard Infinity -0.05 1 .762 0 Vig

3 EvenAsph 1 .954112 0.658876 APEL5514ML 1 .86811 0 L1

4 EvenAsph -1 6.4984 0.123812 1 .900083 0

5 EvenAsph 28.78283 0.537232 EP5000-F 1 .936491 0 L2

6 EvenAsph 2.7513 0.242475 2.0091 9 0

7 Standard Infinity 0.05 2.05 0

8 Standard Infinity 0.08601 6 2.05 0

9 EvenAsph -34.5053 0.862679 APEL5514ML 2.120461 0 L3

10 EvenAsph -6.1921 6 0.424308 2.71 6502 0

11 EvenAsph 2.722564 0.5091 04 APEL5514ML 3.355454 0 L4

12 EvenAsph -4.26721 -0.1 9 4.009626 0

13 Standard Infinity 0.05 4.1 6 0

14 Standard Infinity 0.389066 4.1 6 0

15 EvenAsph -2.51369 0.4261 01 APEL5514ML 4.449728 0 L5

16 EvenAsph 2.608397 0.329 4.87851 7 0

17 Standard Infinity 0.3 N-BK7 5.233205 0 CG 1 908

18 Standard Infinity 0.55 5.402932 0

Image Standard Infinity 5.91 7565 0

Table 36: Surface Data Summary

R3 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

0.001774

Coefficient on r 6

-0.03857

Coefficient on r 8

0.035738

Coefficient on r 10

-0.00277

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R4 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.00027

Coefficient on r 6

0.001123

Coefficient on r 8

0.000761

Coefficient on r 10

0.006183

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R5 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.04891

Coefficient on r 6

0.029453

Coefficient on r 8

-0.01911

Coefficient on r 10

0.004124

Coefficient on r 12

0

Coefficient on r 14

0

Coefficient on r 16

0

R6 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.13503

Coefficient on r 6

0.048368

Coefficient on r 8

0.001742

Coefficient on r 10

-0.00582

Coefficient on r 12

0.00078

Coefficient on r 14

5.79E-05 Coefficient on r 16

0.000106

R7 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.1187

Coefficient on r 6

0.031933

Coefficient on r 8

-0.0214

Coefficient on r 10

0.008804

Coefficient on r 12

-0.0012

Coefficient on r 14

-0.00074

Coefficient on r 16

0.00021 6

R8 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

0.070788

Coefficient on r 6

-0.01663

Coefficient on r 8

-0.00017

Coefficient on r 10

-0.00047

Coefficient on r 12

0.000282

Coefficient on r 14

-1.50E-05

Coefficient on r 16

-2.54E-06

R9 Even Asphere

Coefficient on r 2

0

Coefficient on r 4

0.019234

Coefficient on r 6

0.011958

Coefficient on r 8

-0.00178

Coefficient on r 10

1.79E-05

Coefficient on r 12

5.79E-06

Coefficient on r 14

9.92E-07

Coefficient on r 16

4.90E-08 IO Even Asphere

Coefficient on r 2

0

Coefficient on r 4

-0.10214

Coefficient on r 6

0.027793

Coefficient on r 8

-0.0071

Coefficient on r 10

0.000868

Coefficient on r 12

1.66E-05 Coefficient on r 14

-1 .31 E-05

Coefficient on r 16

7.35E-07

Table 37: Surface Aspheric Coefficients

Table 38: Edge Thickness Data

APEL

5514

15 ML 20 1 1 .552896 1 .549574 1 .546504 1.543579 1 .541977

16 20 1 1 1 1 1 1

17 N-BK7 20 1 1 .523605 1 .520769 1 .518274 1.515909 1.51452

18 20 1 1 1 1 1 1

19 20 1 1 1 1 1 1

Table 39: Index of Refraction Data

Table 40: F/Number Data

Table 40A: F/Number Data (Continued)

[00117] Tables 32 - 40A provides optical and image characteristics for the optical system of Figure 28A, having a far field focus configuration. Table 32 provides general optical information for this optical system. Table 33 provides image heights in the y axis, measured at an image sensor of the optical system, for a set of optical fields and respective weights for the respective optical fields. Table 34 includes vignetting data for the set of optical fields of Table 33. Table 35 depicts wavelengths of respective rays traced in the optical imaging system of Figure 28. Table 36 provides a summary of general optical surface characteristics for lenses of this optical system, including surface type, radius of curvature, thickness, material (from standard glass and plastic catalogues), diameter, conic constant and applicable notes. Table 37 describes aspheric coefficients for the surfaces of Table 35, whereas Table 38 provides edge thickness information for those surfaces. Table 39 provides index of refraction data for multiple wavelengths and listed optical fields. Tables 40 and 40 A provide F/# data for those same wavelengths and optical fields.

[00118] As utilized herein, the word "exemplary" is intended to mean serving as an example, instance, or illustration. Any aspect or design described herein as

"exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form.

[00119] Furthermore, various portions of electronic systems associated with disclosed optical systems described herein may include or consist of artificial intelligence or knowledge or rule based components, sub-components, processes, means, methodologies, or mechanisms (e.g. , support vector machines, neural networks, expert systems, Bayesian belief networks, fuzzy logic, data fusion engines,

classifiers...). Such components, inter alia, and in addition to that already described herein, can automate certain mechanisms or processes performed thereby to make portions of the systems and methods more adaptive as well as efficient and intelligent. For instance, such components can automate optimization of image quality of an optical system, as described above (e.g. , see electronic device 500 of Figure 5, supra).

[00120] What has been described above includes examples of aspects of the claimed subject matter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the claimed subject matter, but one of ordinary skill in the art can recognize that many further combinations and permutations of the disclosed subject matter are possible.

Accordingly, the disclosed subject matter is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the terms "includes," "has" or "having" are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim.

Claims

CLAIMS What is Claimed is:

1. An optical imaging system arranged along an optical axis, comprising:

a set of optical lenses including a first lens group and a second lens group, wherein the second lens group is fixed in position along the optical axis;

a micro electromechanical system (MEMS) actuator mechanically connected to the first lens group and configured to adjust a position of the first lens group along the optical axis, wherein a first adjusted position is configured to focus an image of an object positioned far from the optical imaging system onto an image plane associated with the optical imaging system, and wherein a second adjusted position is configured to focus an image of an object positioned near to the optical imaging system onto the image plane;

wherein:

the set of optical lenses comprising five lenses;

the MEMS actuator is configured to adjust a position of the first lens group along the optical axis up to between 50 and 150 micrometers;

the first optical lens group comprising a biconvex object-side lens; and a ratio of the focal length of the biconvex object-side lens to a combined focal length of the five lenses is greater than one half.

2. The optical imaging system of claim 1 , further comprising an aperture stop positioned at an object-side of the biconvex object-side lens.

3. The optical imaging system of claim 2, wherein the aperture stop is fixed in position along the optical axis.

4. The optical imaging system of claim 2, wherein the aperture stop is fixed in position relative to the first lens group.

5. The optical imaging system of claim 4, wherein the MEMS actuator is configured to reposition the first lens group and the aperture stop along the optical axis and maintain the fixed position between the aperture stop and the first lens group at least at the first adjusted position and at the second adjusted position.

6. The optical imaging system of claim 1, the second lens group comprising four lens elements, including a second lens, a third lens, a fourth lens and a fifth lens.

7. The optical imaging system of claim 6, the second lens having a concave image- side surface and a flat or a weak convex curvature on an object-side surface.

8. The optical imaging system of claim 7, the second lens having a negative optical power, and formed of an OKP4HT plastic.

9. The optical imaging system of claim 6, the third lens having a concave object- side surface and a convex image-side surface, a positive optical power, and formed of an APEL5514ML glass.

10. The optical imaging system of claim 6, the fourth lens having an object-side surface that is convex near the optical axis and transitions to concave away from the optical axis, and an image-side surface having convex curvature.

11. The optical imaging system of claim 10, the fourth lens having positive optical power near the optical axis, and having small negative optical power, small positive optical power, or no optical power away from the optical axis, and the fourth lens is formed of an APEL5514ML plastic.

12. The optical imaging system of claim 6, the fifth lens having an object-side surface that is concave near the optical axis and that transitions to convex away from the optical axis, and an image-side surface that is concave near the optical axis and transitions to convex away from the optical axis.

13. The optical imaging system of claim 12, the fifth lens having large negative optical power near the optical axis, and positive optical power away from the optical axis, and the fifth lens is formed of an APEL5514ML plastic.

14. The optical imaging system of claim 1, the biconvex object-side lens is formed of an APEL5514ML plastic.

15. The optical imaging system of claim 1, wherein an optical power of the biconvex object-side lens is at least in part a function of a distance along the optical axis between the first adjusted position and the second adjusted position.

16. The optical imaging system of claim 1, wherein the ratio of the focal length of the biconvex object-side lens to a combined focal length of the five lenses is about three quarters.

17. The optical imaging system of claim 1, wherein the ratio of the optical power of the biconvex object-side lens to a combined optical power of the five lenses is at least in part a function of a distance along the optical axis between the first adjusted position and the second adjusted position.

18. The optical imaging system of claim 1, wherein the object positioned far from the optical system is positioned substantially at infinity, and wherein the object positioned near to the optical system is positioned at substantially 10cm from an aperture stop of the optical imaging system.

19. An optical system comprising:

a plurality of optical elements arranged along a common optical axis for forming a real image of an object, said optical elements including:

a first lens having a positive refractive power, with both surfaces, one facing an object side and another facing an image side, having convex shape;

a second lens having negative refractive power and a meniscus shape, with the surface facing the object side having a convex shape and the surface facing the image side having a concave shape;

a third lens having positive refractive power, and a biconvex shape near the optical axis, and the surface facing the object side is concave away from the optical axis;

a fourth lens, with the surface facing the object side having a concave shape, and the surface facing the image side having a convex shape; and

a fifth lens having a meniscus shape with the surface facing the object side having a convex shape and the surface facing the image side having a concave shape near the optical axis and a convex shape away from the optical axis; and

an actuator configured to move the first lens along the optical axis.

20. The optical system of claim 19, wherein the motor is a microelectromechanical system.

21. The optical system of claim 19, wherein the second lens performs a majority of chromatic correction for the optical system.

22. The optical system of claim 19, further comprising an aperture that is embedded into the first lens and moves with the first lens, wherein the aperture having a depth of 50μιη.

23. The optical system of claim 19, wherein the F- number of the optical system is approximately 2.4.

24. The optical system of claim 19, wherein one or more of the lenses are made of plastic.

25. The optical system of claim 19, wherein the surfaces of the lenses are aspheric.

26. The optical system of claim 19, wherein the refractive index of the lenses is within a range of about 1.5 to about 1.66.

27. The optical system of claim 19, wherein the range of movement for the first lens is between about Ομιη and about ΙΟΟμιη.

28. The optical system of claim 19, wherein an amount of movement to focus an image of an object is inversely proportional to the positive refractive power of the first lens.

29. The optical system of claim 19, wherein the primary lateral color range for the optical system focused on an object at infinity is equal to or less than approximately Ιμιη.

30. The optical system of claim 19, wherein the primary lateral color range for the optical system focused on an object at 10cm is equal to or less than approximately 4μιη.

31. An optical imaging system arranged along an optical axis, comprising:

a set of optical lenses including a first lens group and a second lens group, wherein the second lens group is fixed in position along the optical axis and comprises a majority of the optical lenses of the set of optical lenses; and

an actuator mechanically connected to the first lens group and configured to adjust a position of the first lens group along the optical axis, wherein a first adjusted position is configured to focus an image of an object positioned far from the optical imaging system onto an image plane associated with the optical imaging system, and wherein a second adjusted position is configured to focus an image of an object positioned near to the optical imaging system onto the image plane;

wherein:

the set of optical lenses comprising five lenses;

the actuator is configured to adjust a position of the first lens group along the optical axis up to between 50 and 150 micrometers;

the second optical lens group comprising a third lens of the set of optical lenses that is third in sequence from an object side of the set of optical lenses, the third lens having a meniscus shape that is convex toward the object side of the set of optical lenses.

32. The optical imaging system of claim 31, wherein the actuator comprises a micro electromechanical system (MEMS) actuator.

33. The optical imaging system of claim 31, the first optical lens group comprising a biconvex objective lens that provides a majority of the positive optical power of the set of optical lenses.

34. The optical imaging system of claim 33, wherein the biconvex objective lens has greater positive refractive power than a combined refractive power of the set of optical lenses.

35. The optical imaging system of claim 31, wherein an effective focal length of the set of optical lenses is between about 4.5 and about 5.0 millimeters.

36. The optical imaging system of claim 31, wherein a ratio of total track length to effective focal length of the optical system is between about 1.1 and about 1.2.

37. The optical imaging system of claim 31, wherein the first lens group comprises a single lens of the set of optical lenses.

38. The optical imaging system of claim 37, wherein the single lens is an objective lens of the optical system.

39. The optical imaging system of claim 37, wherein the second adjusted position focuses an image of an object at an object distance of about 12.8 centimeters onto the image plane.

40. The optical imaging system of claim 31 , wherein an air distance between a third lens and a fourth lens of the set of optical lenses, numbered from an object side of the set of optical lenses, is a largest of air distances between respective ones of the set of optical lenses.

41. The optical imaging system of claim 31, wherein an air distance between a fourth lens and a fifth lens of the set of optical lenses, numbered from an object side of the set of optical lenses, is a largest of air distances between respective ones of the set of optical lenses.

42. The optical imaging system of claim 31 , further comprising an aperture stop about an object side surface of a first lens of the set of optical lenses, numbered from an object side of the set of optical lenses.

43. The optical imaging system of claim 42, further comprising a stop between a second and third lens of the set of optical lenses, numbered from an object side of the set of optical lenses.

44. The optical imaging system of claim 43, further comprising a second stop between the third lens and a fourth lens of the set of optical lenses.

45. The optical imaging system of claim 44, further comprising a third stop between the fourth lens and a fifth lens of the set of optical lenses.